Loading...
HomeMy WebLinkAboutWPO201900015 Calculations 2019-09-25TIMBERWOOD SQUARE HYDROLOGIC/HYDRAULIC CALCULATIONS FOR TIMBERWOOD SQUARE September 25th, 2019 LOCATION: Tax Map 46, Section B4 Parcels 7A, 7B, & 7 City of Charlottesville, Virginia OWNER/DEVELOPER: HighlifeTownhomes, Inc Highlife Office, Inc Highlife, LLC 307 West Rio Rd Charlottesville, VA 22901 PREPARED BY: Roudabush, Gale & Associates, Inc. 172 South Pantops Drive Charlottesville, VA 22911 P: 434.977.0205 1CL014A Summary: APPROVED by the Albemarle County Community Developpment Department Date 09/26/2019 File WP0201900015 2-4 lAppendix 5D Worksheets: 5-20 Preliminary Hydrographs: 21-22 Postdeveloped Hydrographs: 23-24 Inlet DA Hydrographs and Pipe Reach system: 25-141 Unchanged sheets from SDP198800003: 142-206 Time of Concentration Proposed: 207 C factor Calculation: 208 Arbor Lake Inflow Hydrograph: 209-211 Arbor Lake Routed: 213-215 TIMBERWOOD SQUARE Stormwater Management Narrative: 9VAC25-870-48. Grandfathering. A. Any land -disturbing activity shall be considered grandfathered by the VSMP authority and shall be subject to the Part II C (9VAC25-870-93 et seq.) technical criteria of this chapter provided: 1. A proffered or conditional zoning plan, zoning with a plan of development, preliminary or final subdivision plat, preliminary or final site plan, or any document determined by the locality to be equivalent thereto (i) was approved by the locality prior to July 1, 2012, (ii) provided a layout as defined in 9VAC25-870-10, (iii) will comply with the Part II C technical criteria of this chapter, and (iv) has not been subsequently modified or amended in a manner resulting in an increase in the amount of phosphorus leaving each point of discharge, and such that there is no 1 increase in the volume or rate of runoff, 2. A state permit has not been issued prior to July 1, 2014; and 3. Land disturbance did not commence prior to July 1, 2014. B. Locality, state, and federal projects shall be considered grandfathered by the VSMP authority and shall be subject to the Part I1 C technical criteria of this chapter provided: 1. There has been an obligation of locality, state, or federal funding, in whole or in part, prior to July 1, 2012, or the department has approved a stormwater management plan prior to July 1, 2012; 2. A state permit has not been issued prior to July 1, 2014; and 3. Land disturbance did not commence prior to July 1, 2014. C. Land disturbing activities grandfathered under subsections A and B of this section shall remain subject to the Part II C technical criteria of this chapter for one additional state permit cycle. After such time, portions of the project not under construction shall become subject to any new technical criteria adopted by the board. D. In cases where governmental bonding or public debt financing has been issued for a project prior to July 1, 2012, such project shall be subject to the technical criteria of Part II C. E. Nothing in this section shall preclude an operator from constructing to a more stringent standard at his discretion. `A TIMBERWOOD SQUARE This project has a preliminary plan that was approved prior to July Ist, 2012. The new plan has been subsequently modified in a manner resulting in an increase in the amount of phosphorous leaving each point of discharge and such that there is an increase in the volume or rate of runoff. In order to qualify for the grandfathering terms we have provided a biofilter in order to reduce the amount of phosphorous and water quantity to the preliminary plan levels before purchasing offsite nutrient credits and using Arbor Lake for the 2yr and 10yr storm reductions (see attached water quality worksheets for clarity). The sizing of the biofilter is based off of the impervious areas from DA-EX4, DA-3, DA-2 and the back of Townhouse lots 25-32. Sizing for the Stormwater Management Handbook is based off of the impervious area flowing to it. We are using 2.5% of the impervious areas from this drainage area for 820 sf of biofilter area. The first flush of water from these immediate drainage areas will flow to the biofilter other waters will bypass the splitter structure and eventually into Arbor Lake. See routing calculations for the splitter structure and reductions to preliminary plan levels. Existing stormwater management facility (ID 56.01) known as "Arbor Lake" will be used for water quantity. A Forest Lakes Master Drainage Plan from the time of the original design of the pond (1988) anticipates commercial use where the Timberwood Square development is located. The design of the pond preceded the Stormwater Management Handbook and therefore, did not have any nutrient removal rate capability that could be used for the Timberwood Square site. Community Development has asked the applicant to perform a comparison analysis of the original routing design of SWF 56.01 and our proposed routing to see what happens to the water surface elevations of different stone events. There has been a net decrease in the proposed 1Oyr, and 100yr water surface elevations due to a decrease in the total drainage area to Arbor Lake. Refer to separate SWM Maintenance Agreement from the forest Lakes HOA to use Arbor Lake for stormwater quantity control. The remaining water quality control for Timberwood Square will be handled by a biofilter and offsite utilizing the Nutrient Credit Bank system. Overland, VA LLC has agreed to a nutrient exchange of 2.82 Ibs of Phosphorous per year based off of the increased impervious area of 1.68 Acres. A performance -based water quality calculation has been provided to determine the relative pollutant removal requirement. A letter of availability has also been provided with this submittal. Calculations from approved plans by Applied Technology and Engineering, P.C. were used for the existing stormwater management facility design. TIMBERWOOD SQUARE 1988 Applied Technology and Engineering P.C. approved design parameters *Post -developed 1988 APTE WSE has not been adjusted based on As -Built data* PREDEVELOPED POSTDEVELOPED AREA (Ac) 190 190 C 0.3 0.4 Tc (Min) 26 24 I10 (in/hr) 3.5 3.65 I100 (in/hr) 5.1 5.35 Q10 cfs) 199.5 277.4 Q100 (cfs) 290.7 406.6 Postdeveloped 1988 Postdeveloped 2019 (peak dischar Re Normal Pool = 473.00' Normal Pool = 473.24' Q10 inflow = 277.4 cfs Q10 inflow = 284.77 cfs Q 100 inflow = 406.6 cfs Q 100 inflow = 386.82 cfs 10YR W SE = 474.74' (Q l O peak = 79.70 cfs) 1 OYR WSE = 474.67' (Q 10 peak = 71.79 cfs) 100YR WSE = 475.57' (Q100 peak = 96.42 cfs) 100YR WSE = 475.18' (Q100 peak = 81.15 cfs) Rainfall Intensity Justification The rainfall intensity for the 1988 APTE study was done using the Intensity -Duration - Frequency curves. See the attached IDF curve for the correct use of 3.65 in/hr for the 10-year storm and 5.35 in/hr for the 100-year storm. VDOT encourages designers to use the B, D and E factors values for use with the Rational Method. The rainfall IDF values are described by the equation: B 1= (Tc+D)^E There are no B, D, E values for Albemarle County so the Charlottesville BDE values were used in its place (see attached chart). I10 for 24 min Tc is 3.53 in/hr 49.49 (24+9.85)^0.75 I100 for 24 min Tc is 4.79 in/hr 47.51 (24+8.34)^o.66 0 e .MINE MOIN EN ®�\�1®�01 ►"iMUNINNININ, i i i � • # .i Source: VDOT 1992 Plate 5-8 C'm3 Chapter 6 - Hydrology Appendix 6C-2 B, D, and E Factors B. D. R E faemn O+rdelennining ninfdl mh-nsily in the Rational and Modified Rational Methods (ha ed on NOA k NW-14 Atha dal:) 1-YR 2-YR 5-YR 10-YR 25-YR 50-YR ]00-YR STATION ID B D I E B D I E B D I E B D E B D E B D E B D E Ahimgdnn 3S 44-00-11 4RIN 11.74 0.96 49.15 12,15 0.S7 56.06 11S6 0.S5 59.35 12.91 0.54 61.55 12.56 0.91 6263 12.31 0.7R 63.71 1210 0.76 Akin Udon 7 WSW 44-0013 47 34 12_21 (L8S 49,59 12.21 0.87 5626 ❑.74 0.85 59,35 12.75 0,84 62.41 12.70 0 SI 63.39 12.46 0.79 63.54 1'-.44 077 Alluonia 2 SSE 44-0135 4150 1196 R47 49.41 12.26 0.87 5534 12.54 0.84 53.04 1212 OR'- 59.43 11.94 0.78 58.83 11.53 0.76 57.64 10.91) 0.74 Alncista 44-0166 4301 1)97 OS4 51.76 11.34 0.84 5fi05 11 An 0.91 57.34 11.01 0.75 55,75 10.31 0.74 51.93 9.81 0.71 52.14 925 0.69 Am6a 45W 44-0187 456S II.I'_ 0.54 54.40 11.55 0.94 58.09 11.54 O,SI 5826 1098 0.75 56.74 10.37 0.74 55.81 9.91 0.71 53.17 9,21 0.68 Aminrillc 4441103 41 1 1 1045 0.43 50.12 10,79 OR3 55.24 1OSO 0.41 56.53 10.51 0.75 55.74 9.75 0.74 54.80 9.11 0.71 53.46 9,54 0.6.4 Appommink 4441243 41.20 10.74 0.53 49.67 11. I6 0.83 5295 II.(TR TIM 54.17 10.74 0.77 5297 10.06 0.73 51.54 9.50 0.70 49.67 8.02 0.67 Ashland I SW 44-0-321 44 en 1094 0.84 52.62 1 LI 1 0.53 5633 11.15 0.8(1 5721 10.73 0,77 56.07 10.14 07.1 55.04 9.68 0.71 52.71 9,01 0.6S Back Ba) Wildlife 44-01%5 M. 53 os 11.15 0.85 59.65 11.38 0.54 54.44 1 L'_0 0.50 (11.10 I0.R4 0.77 5858 10.07 0.73 59.22 9.46 0.70 57.04 8.76 0.67 Bedford 44-W51 17 67 10.46 0.82 45.55 1094 0.92 50.40 10.91 11.79 51.89 10.64 0.17 51.55 10.03 0.73 50.54 9.57 0.70 44.91 4.99 OAS He "dw,, 44-0670 1,.70 o.20 0Q84 44,43 9.46 0.54 47.92 9.02 0,90 4921 R 53 0.78 49.83 7.75 0,74 49.99 7.14 0,71 4954 6.50 0.69 Bi•\7cadou, '_ 44-07](1 ;5.14 924 0.52 46.37 9AS 082 5045 927 0.71) 50.00 8.57 0.75 4965 7.79 072 4946 7.02 0.69 47.82 6.49 0.66 Biu St. 9u,(1a1 44-0733 4103 1146 0,96 49.16 11.90 0.46 55.20 1220 0.33 59.15 1223 0.S2 61.10 11.90 0.78 6205 11.42 0.76 63.99 11.25 0.74 Blacksburg 44-0765 3941 11.59 096 46.75 1144 0.85 52S8 1209. 0.93 54.67 1IA4 0.90 55.05 11.37 0.77 53.76 10.89 0.75 52.89 10.49 0.72 Rlnckehul g 3 Sli 44-0766 :9 .v7 11 64 0,136 4690 1 I CO 0.85 52.71 1195 9.83 54,71 11.75 0.80 54.72 11.21 0-77 53.42 10.73 0.74 52,9S 10.39 0.72 RlackNonc Wmcr Wm1c 44-077R 47.55 ILIS 0.85 57.66 11.62 0.85 61-12 1166 0.51 61.53 11.16 0.78 5593 IOAO 0.74 57.64 9.90 071 53.04 9.25 0.6.9 Bland 44-071" 11957 IISO 0S7 45,97 II.99 0.M 52.78 1234 0.M 5593 1226 0.82 55.71 12.11 0.79 59.90 11.88 0,77 60.64 11.55 0.75 Brcmn BlufI PuT 44-099' I6(, I LO1 0 84 45.44 10.84 0.92 47.37 1009 0.80 51.96 M83 0.77 50.16 10.06 0.73 50.71 9.67 0.71 49.32 9.16 0.64 Brookneal 44-1051 4i 17 11 34 0A5 5253 I IIS 0.84 57.02 11.41 0.51 57,13 11.00 0.75 56.50 10.42 0.74 54.70 9.97 0.71 5227 9.16 0.64 B9chmum 44-1121 37 03 10 71) 0.53 44.69 11.09 O.93 50.96 11.18 0.S1 51.57 10.98 0.78 51.57 10.37 0.74 51.00 9.95 0.72 50.15 9.54 0 69 Mackin^hmn 44-1116 403S In 66 0.83 46.65 I(L80 O.92 5125 11.10 0.90 5315 10.75 0.77 51.91 10.03 0.71 50.52 9.40 0.70 40.20 9.90 0.67 Buena \'i>u 44-IIp1 3749 11.10 0.,l'5 4539 11.50 0.55 51 An 11.77 0.42 54.43 11.67 0.0 53.71 WAR 0.76 54.10 10. 73 074 5158 10.35 0.72 Hnikcs Oankn 4441_011 1900 1145 096 46.42 1174 0,45 51.87 1204 103 55.10 11.97 0.81 56.42 11.47 0.75 59.60 11.52 0.76 60-RI 11.26 0.72 BAk,hv 3 \P 44-1251) .In DN 11.76 0-R6 46.35 11 SO 0 86 53.19 12.20 0.R3 55.73 12.01 0.41 58.62 11.79 0.78 59.61 I L50 0.76 61.47 I L34 0.74 Camp PickcO 44-1322 4R 57 11.29 0.95 5725 11.47 0.54 61.39 TIM TIM 61.86 11.13 0.18 58.96 1027 0.74 58.70 10.01 0.71 56.01 9.35 0.65 ('m:udla 44-1471 San;norimn 17.71 1091 0.44 45.37 11.10 0..93 5226 11.55 0.81 53.70 1124 079 5321 10,59 0.75 52.90 10.26 0.7.1 52-221 9,35 0.70 (3mddtc Cu9n Ilse 3\\' 44-ISRi 471S 111-- Ok5 54.56 IL54 0R4 55.4(1 1147 O.S1 6003 1L22 0.7K 5746 10-5 0.74 1 56A5 9,93 f1.71 535d 911) ()6S "14 9 - 10 5 chase Cih. 44-loon 1%14 11.37 0.45 5569 IL5_ O.Sd 59.04 II49 O.SI 6040 I1IS 07R 54.34 10.42 Ilt 56.52 493 0.7I 54.19 2'4 un5 1 of 6 VDOT DRAINAGE MANUAL PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 1 Page t of 3 PreI : la Si: C et_r 10—Zs1 II Determine the applicable area (A) and the post -developed impervious cover upe,t)• Applicable area (A)* = S. S 6 61 acres Post -development impervious cover: structures acres parking lot acres roadway = acres other: WO PCs = o . Zt ti l acres acres Total = 2 `1 ` '13 acres fleet = (total post -development impervious cover _ A) x 100 = y 1 - 2 % The area subject to the criteria may vary from locality to locality. Therefore, consult the locality for proper determination of this value. STEP 2 Determine the average land cover condition (I..,b d) nx the existing impervious cover (I.ist;nd. Average land cover condition (i..,hd): If the locality has determined land cover conditions for individual watersheds within its jurisdiction, use the watershed specific value determined by the locality as '.,,,hed• I.tashed = 1 t0 % Otherwise, use the Chesapeake Bay default value: �.tsshed _ 16% 5D-5 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet1 Page 2 of 3 Determine the existing impervious cover of the development site if present. Existing impervious cover: structures=--D—. —I'Lacres parking lot = Q 9D nacres roadway = acres other: WrOk 5 _ O. O-� acres acres Total = —L l 1. acres I,j; tj.g = (total existing impervious cover —A*) X 100 = M • g The area should be the same as used in STEP 1. STEPS Determine the appropriate development situation. The site information determined in STEP 1 and STEP 2 provide enough information to determine the appropriate development situation under which the performance criteria will apply. Check (✓) the appropriate development situation as follows: Situation 1: This consists of land development where the existing percent impervious cover (Lj,,j.g) is less than or equal to the average land cover condition (Ig�h.d) and the proposed improvements will create a total percent impervious cover (I..) which is less than or qual to the average land cover condition (I,.,�J. T Ipost 0 �0 :� watershed % 5D-6 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 1 Page 3 of 3 Situation 2: This consists of land development where the existing percent impervious cover (Lxi c d is less than or equal to the average land cover condition (Iwa heD and the proposed improvements will create a total percent impervious cover (1j which is greater than the average land cover condition Iexlsting O"n 5 Iwatasbed %; and 0 (post �n > lwatenhed % f Situation 3: This consists of land development where the existing percent impervious cover (Ie �x;�� is greater than the average land cover condition (J.,, �j. /-t (O1 0 % (existing I "� O �n � (watershed Situation 4: This consists of land development where the existing percent impervious cover (IeXs,d is served by an existing stormwater management BMP(s) that addresses water quality. If the proposed development meets the criteria for development Situation 1, than the low density development is considered to be the BMP and no pollutant removal is required. The calculation procedure for Situation 1 stops here. If the proposed development meets the criteria for development Situations 2, 3, or 4, then proceed to STEP 4 on the appropriate worksheet. 5D-7 PERFORMANCE -BASED WATERQUALITY CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 1 of 5 Summary of Situation 3 criteria: from calculation procedure STEP I thru STEP 3, Worksheet 1: Applicable area (A)* = 5 .• &-1 acres Inns, = (total post -development impervious cover z- A) x 100 = 21-1 Iwatershed _ f G°/n . or IA.atershed = 16% 'existing = (total existing impervious cover- A*) x 100 = 19 , 8 % 0 Iexisting 19.8 °/" > Iwatershed I(*/^ STEP Determine the relative pre -development pollutant load (Lin.). 1. Pre -development pollutant load based on the existing impervious cover: Lpre(existing) _ 10-.05 + (0.009 x Iexisting)) x A x 2.28 (Equation 5-17) where: Lpm(existing) = relative pre -development total phosphorous load (pounds per year) ICx;sting = existing site impervious cover (percent expressed in whole numbers) A = applicable area (acres) Lpre(existing) _ [0.05 + (0.009 x l°t. A )]x "'I x 2.28 = 3.05 pounds per year 5D-13 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 2 of 5 2. Pre -development pollutant load based on the average land cover condition: Lpre(watenhed) _ [0.05 + (0.009 x Iwx,e hed)] x A x 2.28 (Equation 5-16) where: Lp1e(WdC1h4 = relative pre -development total phosphorous load (pounds per year) IWa1C1s,ed = average land cover condition for specific watershed or locality or the Chesapeake Bay default value of 16% (percent expressed in whole numbers) A = applicable area (acres) Lpre(watershed) _ [0.05 + (0.009 x � (p .)] x S . 8 } x 2.28 = 2 • (,° pounds per year STEP 5 Determine the relative post -development pollutant load (LP j. Lpost = [0.05 + (0.009 x I . J] x A x 2.28 (Equation 5-21) where: Leos, = relative post -development total phosphorous load (pounds per year) 'punt = post -development percent impervious cover (percent expressed in whole numbers) A = applicable area (acres) Lpost = [0.05 + (0.009 x 4 11 )] x 5 .Bl x 2.28 S.49 pounds per year STEP 6 Determine the relative pollutant removal requirement (RR). M RR = Lpost — (0•9 x LPre(adstin9)) = S . 69 - (0.9 x 1 05 ) = 2.. 9 5 pounds per year RR = Lpost - LP.(. mW hea) = 55, q - Z.t.a = 1-01 pounds per year 5D-14 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D' Worksheet 3 ; Situation 3 Page 3 of 5 The pollutant removal requirement (RR) for Situation 3 is the lesser of the two values calculated above: RR = 2.55 pounds per year Pr, ( ,,-ti,.r' P�,.r P4.rW-0 ftAa W STEP 7 Identify best management practice (BMP) for the site. 1. Determine the required pollutant removal efficiency for the site: EFF = (RR—, Lpon) x 100 (Equation 5-22) where: EFF = required pollutant removal efficiency (percent expressed in whole numbers) RR = pollutant removal requirement (pounds per year) Lpos, = relative post -development total phosphorous load (pounds per year) EFF = ( — ) x 100 2. Select BMP(s) from Table 5-15 and locate on the site: BMP BMP 5D-15 PERFORIM ANCE-BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 4 of 5 3. Determine the pollutant load entering the proposed BMP(s): LBmr = [0.05 + (0.009 x IBA)] x A x 2.28 (Equation 5-23) where: LBw = relative post -development total phosphorous load entering proposed BMP (pounds per year) IBw = post -development percent impervious cover of BMP drainage area (percent expressed in whole numbers) A = drainage area of proposed BMP (acres) Lnw, _ [0.05 + (0.009 x )] x x 2.28 = pounds per year LBW2 = [0.05 + (0.009 x )] x pounds per year LBMP3 = 10.05 + (0.009 x )] x pounds per year x 2.28 x 2.28 4. Calculate the pollutant load removed by the proposed BMP(s): Lremoved _ EffB„e x LBMP (Equation 5-24) where: L1C0o ed = Post -development pollutant load removed by proposed BMP (pounds per year) EffBw = pollutant removal efficiency of BMP (expressed in decimal form) LBO = relative post -development total phosphorous load entering proposed BMP (pounds per year) LmovedMWI = x = pounds per year L'remove&BM 2 = x = pounds per year LmmovedMW3 = x = pounds per year 5D-16 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 5 of 5 5. Calculate the total pollutant load removed by the BMP(s): Lr oved/totat = L,aa,..mwt + L,e ,dBw2 + Lrom0vedBMr3 +. - . (Equation 5-25) where: L..,d to, j = total pollutant load removed by proposed BMPs L..&BW1= pollutant load removed by proposed BMP No. 1 = pollutant load removed by proposed BMP No. 2 Ll.edBM93 = pollutant load removed by proposed BMP No. 3 Ltemovedttotat = + + + .. . 6. Verify compliance: Lretoavedttotal 2 RR 2 pounds per year SD-17 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 1 Page t of 3 Pr0P-rcA STEP Determine the applicable area (A) and the post -developed impervious cover l+rtp.J• Applicable area (A)* = 5 Al acres Post -development impervious cover: other. structures = 1- 0 L acres parking lot = L S S acres roadway = acres = 0'273 acres acres Total = r - $ `t acres I�n = (total post -development impervious cover - A) X 100 = `t .g • N The area subject to the criteria may vary from locality to locality. Therefore, consult the locality for proper determination of this value. STEP 2 Determine the average land cover condition \'watershed) ar the existing impervious cover Average land cover condition (i a enaom: If the locality has determined land cover conditions for individual watersheds within its jurisdiction, use the watershed specific value determined by the locality as I.,.,,,d. 'watershed = I ( % Otherwise, use the Chesapeake Bay default value: watershed = 16% 5D-5 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 1 Page 2 of 3 Y1 1 ' 11 MA 1 y Determine the existing impervious cover of the development site if present. Existing impervious cover: structures = • Z°I acres parking lot =--2, a ° acres roadway = acres other: wv�1�-t — 0•01 acres acres Total — --Lk —(-acres IC%15ting = (total existing impervious cover = A*) x 100 = I) - I % The area should be the same as used in STEP 1. STEP 3 Determine the appropriate development situation. The site information determined in STEP 1 and STEP 2 provide enough information to determine the appropriate development situation under which the performance criteria will apply. Check (✓) the appropriate development situation as follows: Situation 1: This consists of land development where the existing percent impervious cover (I�-.ng) is less than or equal to the average land cover condition (Ikd1e,h,) and the proposed improvements will create a total percent impervious cover (W which is less than or equal to the average land cover condition \`watershed/• Ipmt d/e < 'watershed % 5D-6 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 1 Page 3 of 3 Situation 2: This consists of land development where the existing percent impervious cover (Iexi54a� is less than or equal to the average land cover condition (Iw„G and the proposed improvements will create a total percent impervious cover &,) which is greater than the average land cover condition (I.,,sshed). 0^ < 0 existing watershed ; and Post 0 �^ TT 'watershed % Situation 3: This consists of land development where the existing percent impervious cover (ICX1S n� is =ater than the average land cover condition llwa ersned) Iexis'existing"' g gin > 'Watershed lG % Situation 4: This consists of land development where the existing percent impervious cover 0existing) is served by anexisting stormwater management BMP(s) that addresses water q tat�lay. If the proposed development meets the criteria for development Situation 1, than the low density development is considered to be the BMP and no pollutant removal is required. The calculation procedure for Situation 1 stops here. If the proposed development meets the criteria for development Situations 2, 3, or 4, then proceed to STEP 4 on the appropriate worksheet. 5D-7 PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Workcheet 3 : Situation 3 Page 1 of 5 Summary of Situation 3 criteria: from calculation procedure STET1 thru STEP 3, Worksheet 1: Applicable area (A)* = S , g} acres IPnSr = (total post -development impervious cover-, A) x 100 = `( Lf % watershed `y ^/^ or wwaterhed = 16% Iuao,g = (total existing impervious cover - A*) x 100 = 0 • I % l l (Io/n ¢sating o/ ^ > k atershed STET' 4 Determine the relative pre -development pollutant load (Lp,). 1. Pre -development pollutant load based on the existing impervious cover: Lpre(ex;sting) _ [0.05 + (0.009 x Iexating)j x A x 2.28 (Equation 5-17) where: Lp.*j,,;,,g) = relative pre -development total phosphorous load (pounds per year) lexisting = existing site impervious cover (percent expressed in whole numbers) A = applicable area (acres) Lpre(existing) _ [0.05 + (0.009 x I" )] x 9.91 x 2.28 3.05 pounds per year ;J909l PERFORMANCE -BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 2 of 5 2. Pre -development pollutant load based on the average land cover condition: Lpre(watenhed) _ [0.05 + (0.009 x `.,ershed)] x A x 2.28 (Equation 5-16) where: Lpfe(w,e hed) = relative pre -development total phosphorous load (pounds per year) 'watershed = average land cover condition for specific watershed or locality ar the Chesapeake Bay default value of 16% (percent expressed in whole numbers) A = applicable area (acres) Lpre(watershed) = [0.05 + (0.009 x 6 )] x S. $3 x 2.28 = z- . v O pounds per year STEP 5 Determine the relative post -development pollutant load (LppJ. —LPost = [0.05 + (0.009-x;,,-)] z A x-2.28 - (Equation 5-21) - — - where: Lpost = relative post -development total phosphorous load (pounds per year) Ip,st = post -development percent impervious cover (percent expressed in whole numbers) A = applicable area (acres) Lpt,st = [0.05 + (0.009 x 4 8 .y )] x S. $ 7 x 2.28 G • S pounds per year STEP! Determine the relative pollutant removal requirement (RR). RR = Lpost — (0.9 x Lpre(e i.ti d = (0.54 - (0.9 x 3 1 5_) = 3 • T & pounds per year RR = Lpost — Lpm(watershed) = = 3 . ` 0 pounds per year 5D-14 PERFORb1ANCE-BASED WATER QUALITY- CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 3 of 5 The pollutant removal requirement (RR) for Situation 3 is the lesser of the two values calculated above: RR = 3 d G pounds per year 1b-bi W:.t t- b- STEP 2 Identify best management practice (BMP) for the site. 1. Determine the required pollutant removal efficiency for the site: EFF = (RR = Lp.) x 100 (Equation 5-22) where: EFF = required pollutant removal efficiency (percent expressed in whole numbers) RR = pollutant removal requirement (pounds per year) Lp"t = relative post -development total phosphorous load (pounds per year) - - - EFF-=-- 2. Select BMP(s) from Table 5-15 and locate on the site: BMPI: BMP IEM 1 5D-15 PERFORNIANCE-BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksh et : Situation 3 Page 4 of 5 3. Determine the pollutant load entering the proposed BMP(s): LBm? = [0.05 + (0.009 x I..)) x A x 2.28 (Equation 5-23) where: LBw = relative post -development total phosphorous load entering proposed BMP (pounds per year) IBw = post -development percent impervious cover of BMP drainage area (percent expressed in whole numbers) A = drainage area of proposed BMP (acres) LBMrt = [0.05 + (0.009 x a-h` • 6 )] x Z, Id x 2.28 • 91' pounds per year LBMr2 = [0.05 + (0.009 x )] x x 2.28 pounds per year LBMr3 = 10.05 + (0.009 x )l x x 2.28 f pounds per year 4. Calculate the pollutant load removed by the proposed BMP(s): Lremoved = EffENT x Lamp (Equation 5-24) where: L,�o d = Post -development pollutant load removed by proposed BMP (pounds per year) EffBte = pollutant removal efficiency of BMP (expressed in decimal form) LBw = relative post -development total phosphorous load entering proposed BMP (pounds per year) Lremoved/BM71 = 0 5 ° x 1• R D • R H pounds per year O lC ✓ LremovedBMP2 = x = pounds per year Lremove&BMP3 _ x = pounds per year 5D-16 "� PERFORNIANCE-BASED WATER QUALITY CALCULATIONS APPENDIX 5D Worksheet 3 : Situation 3 Page 5 of 5 5. Calculate the total pollutant load removed by the BMP(s): Lremovemtutal _ Lmmove&Bhel + Lremove&BNm + Lromoved/Bhp3 +. . • (Equation 5-25) where: Lrema�w,e = total pollutant load removed by proposed BMPs L=movcd,BI Pt = pollutant load removed by proposed BMP No. 1 L1e a C&BMn = pollutant load removed by proposed BMP No. 2 L.mow&BW3 = pollutant load removed by proposed BMP No. 3 Lremoved/tatal _ O.g`I+ + +' ' ' © ri y pounds per year 6. Verify compliance: L,emovedltotal 2 RR 1 Z.SZ fbr f. be Pw.t.�✓ I 5D-17 Hydrograph Report 21 - Hydrafloty Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 93 Preliminary Hydrograph type = Rational Peak discharge = 11.34 cfs frequency = 2 yrs Time to peak = 15 min iStorm Time interval = 1 min Hyd. volume = 10,203 cuft Drainage area = 5.870 ac Runoff coeff. = 0.55 Intensity = 3.511 in/hr Tc by User = 15.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 I Preliminary Q (cfs) Hyd. No. 93 -- 2 Yew 10 8 6 4 2 V VV 0 2 4 Hyd No. 93 6 8 10 12 14 16 18 20 Q (cfs) ).00 RE M RM w 00 22 24 26 28 30 Time (min) Hydrograph Report 22 - nyaranow nyarograpns =x ansian ror,vuioaesKu uvu ouw to 1 c uy r uwucon, uw. vavcu Hyd. No. 93 Preliminary Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 5.870 ac Runoff coeff. Intensity = 4.558 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 12.0 9 9 9 0. 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (min) ® Hyd No. 93 Preliminary Hyd. No. 93 — 10 Year Wednesday, 02 / 20 / 2019 = 14.72 cfs = 15 min = 13,244 cuft = 0.55 = 15.00 min = 1/1 Q (cfs) Hydrograph Report 23 Hyd. No. 94 Postdeveloped Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 5.870 ac Runoff coeff. Intensity = 3.511 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 14.00 12.00 10.00 MIZ . 11 4.00 0 11 Postdeveloped Hyd. No. 94 -- 2 Year Wednesday, 02 / 20 / 2019 = 12.16 cfs = 15 min = 10,945 tuft = 0.59 = 15.00 min = 1/1 Q (cfs) 14.00 12.00 10.00 M 4.00 r M D.00 ' 1 1 1 1 I 1 1 1 1 1 1 1 1 1 31 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (min) ® Hyd No. 94 Hydrograph Report 24 - - Hydraflow Hydrographs Extension for Autodesk® Civil 3DO2019 by Autodesk, Inc. v2020 Hyd. No. 94 Postdeveloped Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 5.870 ac Runoff coeff. Intensity = 4.558 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) Postdeveloped Hyd. No. 94 -- 10 Year Wednesday, 02/20/2019 = 15.79 cfs = 15 min = 14,208 cuft = 0.59 = 15.00 min = 1/1 • --------------- : � � 15.0C 12.0C 9.01 6.01 3.01 n n, 1 1 9 OOF 6 )10 3 1 0 5.00 2.00 X= INIIIIIIII IWIIIIIIII 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time (min) — Hyd No. 94 25 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Thursday, 02 121 / 2019 Hyd. No. 1 DA-EX6 Hydrograph type = Rational Peak discharge = 3.599 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 1,080 cuft Drainage area = 1.050 ac Runoff coeff. = 0.66 Intensity = 5.193 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (cfs) 4.00 2.00 1.00 DA-EX6 Hyd. No. 1 -- 2 Year Q (cfs) 4.00 3.00 2.00 1.00 0.00 Y I I i I I 1 1 31 0.00 0 1 2 3 4 5 6 7 8 9 10 Time (min) — Hyd No. 1 Hydrograph Report 26 rtydranow rryorograpns txtension for.cutoaesK(V uvu suU zu iv oy AutoaesK, Inc. vmzu Hyd. No. 1 DA-EX6 Hydrograph type = Rational Peak discharge r Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 1.050 ac Runoff. coeff. Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) DA-EX6 Hyd. No. 1 -- 10 Year Thursday, 02 / 21 / 2019 = 4.640 cfs = 5 min = 1,392 cuft = 0.66 = 5.00 min = 111 Q (cfs) VyV 0 1 2 3 4 5 6 7 8 9 10 Time (min) — Hyd No. 1 Hydrograph Report 27 HydraFlow Hydrographs Extension for Autodesk® Civil 3DV 2019 by Autodesk, Inc. v2U2U Hyd. No. 2 ' DA-EX5A Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.250 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact DA-EX5A Hyd. No. 2 -- 2 Year Wednesday, 02120 / 2019 = 0.987 cfs = 5 min = 296 cuft = 0.76 = 5.00 min = 1/1 2 3 4 5 6 7 8 9 Q (Cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 10 Time (min) Hydrograph Report 28 - Hydreflow Hydragraphs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 2 DA-EX5A Hydrograph type = Rational Peak discharge r Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.250 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 2.00 1.00 DA-EX5A Hyd. No. 2 — 10 Year Wednesday, 02 / 20 12019 = 1.272 cfs = 5 min = 382 cult = 0.76 = 5.00 min = 1/1 Q (Cfs) 2.00 1.00 0.00 'K II II I I I I I N 0.00 0 1 2 3 4 5 6 7 8 9 10 Hyd No. 2 Time (min) Hydrograph Report 29 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 3 DA-EX5 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.140 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact DA-EX5 Hyd. No. 3 -- 2 Year wee 0 1 2 3 4 5 — Hyd No. 3 Wednesday, 02 / 20 / 2019 = 0.502 cfs = 5 min = 150 cuft = 0.69 = 5.00 min = 1/1 30 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3002019 by Autodesk, Inc. v2020 Wednesday, 02 / 2012019 Hyd. No. 3 DA-EX5 Hydrograph type = Rational Peak discharge = 0.647 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 194 cuft Drainage area = 0.140 ac Runoff coeff. = 0.69 Intensity = 6.695 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 DA-EX5 Hyd. No. 3 — 10 Year 2 3 4 5 6 7 8 9 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 10 Time (min) Hydrograph Report 31 Hydraflow Hydrographs Extension for Autodesk® Civil 31D®2019 by Autodesk, Inc. v2020 Hyd. No. 4 DA-EX4 Hydrograph type = Rational. Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.350 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 2.00 V i, 0 1 — Hyd No. 4 2 3 DA-EX4 Hyd. No. 4 -- 2 Year 4 9 0 7 Q Wednesday, 02 / 2012019 = 1.327 cfs = 5 min = 398 cuft = 0.73 = 5.00 min = 1/1 O Q (cfs) 2.00 1.00 10 Time (min) 32 Hydrograph Report (- Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk. Inc. v2020 Wednesday, 02120 / 2019 Hyd. No. 4 DA-EX4 Hydrograph type = Rational Peak discharge = 1.711 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 513 cuft Drainage area = 0.350 ac Runoff coeff. = 0.73 Intensity = 6.695 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 DA-EX4 Hyd. No. 4 -- 10 Year V VV 0 1 2 3 4 5 6 7 8 9 — Hyd No. 4 10 Time (min) Hydrograph Report 33 Hydraflow Hydrographs Extension for Autodesk® Civil 31)®2019 by Autodesk, Inc. v2020 Hyd. No. 5 DA-EX4A Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.650 ac Runoff. coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 3.00 i•AQ11 1.00 0.00 0 1 — Hyd No. 5 Wednesday, 02/20/2019 = 2.532 cfs = 5 min = 759 cuft = 0.75 = 5.00 min = 1/1 DA-EX4A Hyd. No. 5 -- 2 Year Q (cfs) O nn 2 3 4 5 6 7 8 9 10 Time (min) 34 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 5 DA-EX4A Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.650 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 4. 191 9 0. — 0 1 2 3 4 5 6 7 8 9 10 Time (min) — Hyd No. 5 DA-EX4A Hyd. No. 5 -- 10 Year Wednesday, 02 / 2012019 = 3.264 cfs = 5 min = 979 cult = 0.75 = 5.00 min = 1/1 Q (cfs) 35 Hydrograph Report . Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 6 DA-3 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.050 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact f Q (cfs) I 0.50 I 0.45 0.40 I 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0 1 — Hyd No. 6 DA-3 Hyd. No. 6 — 2 Year Wednesday, 02 / 20 / 2019 = 0.187 cfs = 5 min = 56 cult = 0.72 = 5.00 min = 1/1 2 3 4 5 6 7 8 9 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 10 Time (min) r- 36 1 Hydrograph Report j Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 I Hyd. No. 6 DA-3 I Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.050 ac Runoff coeff. " Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact r Q (Cfs) f 0.5C r 0.4r. r 0.4( I 0.3E 0.3( 0.2E 0.2( 0.1E 0.V 0.0 0.01 0 1 — Hyd No. 6 DA-3 Hyd. No. 6 -- 10 Year Wednesday, 02 120 / 2019 = 0.241 cfs = 5 min = 72 cuft = 0.72 = 5.00 min = 1/1 Q (cfs) 2 3 4 5 6 7 8 9 10 Time (min) Hydrograph Report 37 - Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 0212012019 Hyd. No. 7 DA-2 Hydrograph type = Rational Peak discharge = 2.036 cfs - Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 611 cuft " Drainage area = 0.490 ac Runoff coeff. = 0.8 Intensity = 5.193 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (cfs) V VV 0 1 — Hyd No. 7 DA-2 Hyd. No. 7 -- 2 Year 2 3 4 5 6 7 8 9 Q (Cfs) .00 am 0 00 10 Time (min) Hydrograph Report 38 nyararioW nyorograpns exrension ror AucoaesKV uwi aUV Zu I a oy rwmaesK, Inc. vcuZu Hyd. No. 7 DA-2 Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.490 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 3.00 2.00 1.00 0.00 bE I 0 1 — Hyd No. 7 DA-2 Hyd. No. 7 -- 10 Year Wednesday, 02 / 20 12019 = 2.625 cfs = 5 min = 787 tuft = 0.8 = 5.00 min = 111 2 3 4 5 6 7 8 9 Q (cfs) 3.00 2.00 1.00 3- 0.00 10 Time (min) 39 Hydrograph Report - Hydraflow Hydrographs Extension for AutodeskO Civil 31DO2019 by Autodesk, Inc. v2020 Wednesday, 02 / 2012019 Hyd. No. 8 OFFSITE Hydrograph type = Rational Peak discharge = 7.769 cfs Storm frequency = 2 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 2,331 cuft Drainage area = 1.870 ac Runoffcoeff. = 0.8 Intensity = 5.193 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (cfs) 8.00 w 4.00 iAIQrl 0.00 le I I ' 0 1 2 3 Hyd No. 8 OFFSITE Hyd. No. 8 -- 2 Year 4 5 6 7 Q (cfs) 8.00 18 2.00 N 0.00 8 9 10 Time (min) 40 Hydrograph Report Hydraflow Hydrographs Extension for AutodeskO Civil 3D02019 by Autodesk, Inc. v2020 Wednesday, 02 / 2012019 Hyd. No. 8 OFFSITE Hydrograph type = Rational Peak discharge = 10.02 cfs Storm frequency = 10 yrs Time to peak = 5 min Time interval = 1 min Hyd. volume = 3,005 cuft Drainage area = 1.870 ac Runoff coeff. = 0.8 Intensity = 6.695 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (cfs) 12.00 10.00 Om 6.00 4.00 2.00 0.00 0 1 2 ® Hyd No. 8 OFFSITE Hyd. No. 8 -- 10 Year 3 4 5 6 7 8 Q (cfs) 12.00 Sux11z11 4.00 2.00 0.00 9 10 Time (min) Hydrograph Report 41 i-- Hydraflow Hydrographs Extension for Autodesk®Civi13D®2019 by Autodesk, Inc. v2020 ` • Hyd. No. 9 DA-12 " Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.290 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact DA-12 Hyd. No. 9 -- 2 Year 0 1 2 3 4 5 —Hyd No-9 Wednesday, 02 / 2012019 = 0.527 cfs = 5 min = 158 cult = 0.35 = 5.00 min = 1/1 42 Hydrograph Report - nyaranow nyarograpns tx[ension ror AU[oaeaKIV avu JUV zuia oy AuraaesK, inc. vzvzu Hyd. No. 9 DA-12 Hydrograph type = Rational Peak discharge - Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.290 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0 1 2 — Hyd No. 9 DA-12 Hyd. No. 9 -- 10 Year 3 4 5 6 Wednesday, 02 / 20 / 2019 = 0.680 cfs = 5 min = 204 cuft = 0.35 = 5.00 min 1/1 r - 43 Hydrograph Report i^ Hydraflow Hydrographs Extension for Autodesk® Civil 3DS 2019 by Autodesk, Inc, v2020 Hyd. No. 10 •( DA-13 'I Hydrograph type = Rational Peak discharge f Storm frequency = 2 yrs Time to peak ';� Time interval = 1 min Hyd. volume ' Drainage area = 0.120 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Wednesday, 02120 / 2019 = 0.530 cfs = 5 min = 159 cuft = 0.85 = 5.00 min 1/1 44 Hydrograph Report HydraFlow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 10 DA-13 Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.120 ac Runoff. coeff. Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) DA-13 Hyd. No. 10 — 10 Year Wednesday, 02 / 20 / 2019 = 0.683 cfs = 5 min = 205 cuft = 0.85 = 5.00 min = 1/1 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 V Vv 0 1 2 3 4 5 6 7 8 9 10 Time (min) — Hyd No. 10 45 Hydrograph Report _ - - Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 - Hyd. No. 11 DA-14 Hydrograph type = Rational Peak discharge - Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.150 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 — Hyd No. 11 DA-14 Hyd. No. 11 -- 2 Year Wednesday, 02120 / 2019 = 0.685 cfs = 0.08 hrs = 206 cuft = 0.88 = 5.00 min = 1/1 Q (Cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 000 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) Hydrograph Report 1 Hydraflow Hydrographs Extension for Autodesk® Civil 308 2019 by Autodesk, Inc. v2020 Hyd. No. 11 DA-14 Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.150 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 — Hyd No. 11 Wednesday, 02 f 2012019 = 0.884 cfs = 0.08 hrs = 265 cult = 0.88 = 5.00 min = 1/1 Q (Cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) Hydrograph Report 47 - myora➢ow nyorograpns ❑mension Tor numoesrcw 1 1VU 3UU cu I U uy Auwuubm' II U. v4u4u -_ Hyd. No. 12 DA-5A Hydrograph type = Rational Peak discharge - Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.540 ac Runoff. coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 3.00 2.00 1.00 0.00 if 0.0 0.0 — Hyd No. 12 DA-5A Hyd. No. 12 — 2 Year Wednesday, 02/20/2019 = 2.103 cfs = 0.08 hrs = 631 cuft = 0.75 = 5.00 min = 111 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 Q (cfs) 3.00 2.00 1.00 —X- 0.00 0.2 Time (hrs) Hydrograph Report 48 - Hydraflow Hydrographs Extension for Autodesk® Civil 300 2019 by Autodesk. Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 12 DA-5A Hydrograph type = Rational Peak discharge = 2.712 cfs Storm frequency = 10 yrs Time to peak = 0.08 hrs Time interval = 1 min Hyd. volume = 813 cult Drainage area = 0.540 ac Runoff coeff. = 0.75 Intensity = 6.695 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (Cfs) 3.00 1.00 0.00 = 0.0 0.0 — Hyd No. 12 DA-5A Hyd. No. 12 — 10 Year 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 Q (Cfs) 3.00 2.00 1.00 N 0.00 0.2 Time (hrs) Hydrograph Report I Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 13 DA-6 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.350 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 2.00 1.00 0.00 " ' 0.0 0.0 — Hyd No. 13 DA-6 Hyd. No. 13 -- 2 Year Wednesday, 02 / 20 / 2019 = 1.327 cfs = 0.08 hrs = 398 cult = 0.73 = 5.00 min = 1/1 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 Q (cfs) 2.00 1.00 '_ 0.00 0.2 Time (hrs) Hydrograph Report 50 r nyoranow nyarograpns ezfensfon for rmooesrcv fnvn auwz i uy rfuwueen, uic. vcvice Hyd. No. 13 DA-6 Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.350 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User IN Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 2.00 1.00 DA-6 Hyd. No. 13 — 10 Year Wednesday, 02 / 20 / 2019 = 1.711 cfs = 0.08 hrs = 513 cult = 0.73 = 5.00 min = 1/1 0.00 it 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 Hyd No. 13 Q (cfs) 2.00 1.00 — 0.00 0.2 Time (hrs) r- 51 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 30@ 2019 by Autodesk, Inc. v2020 Hyd. No. 14 -' DA-6A Hydrograph type = Rational Peak discharge r Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.240 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 ® Hyd No. 14 DA-6A Hyd. No. 14 — 2 Year Wednesday, 02 / 20 12019 = 0.997 cfs = 0.08 hrs = 299 cuft = 0.8 = 5.00 min = 1/1 Q (Cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 000 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) 52 ' Hydrograph Report ' Hydraflow Hydrographs Extension for AutodeskV CIVII RM 2019 by AutodesK, Inc. VZUZU Hyd. No. 14 DA-6A Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.240 ac Runoff coeff. r Intensity = 6.695 in/hr Tc by User OF Curve Eli = ALBEMARLE IDF.IDF Asc/Rec limb fact I I Q (Gfs) 2.00 r' 5 1.00 0.00 = 0.0 0.0 — Hyd No. 14 DA-6A Hyd. No. 14 — 10 Year Wednesday, 02/2012019 = 1.285 cfs = 0.08 hrs = 386 cuft = 0.8 = 5.00 min = 1/1 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 Q (cfs) 2.00 1.00 N 0.00 0.2 Time (hrs) Hydrograph Report 53 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 15 DA-8 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.160 ac Runoffcoeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 — Hyd No. 15 DA-8 Hyd. No. 15 -- 2 Year Wednesday, 02 / 20 / 2019 = 0.357 cfs = 0.08 hrs = 107 cult = 0.43 = 5.00 min = 1/1 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 0.00 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) 54 Hydrograph Report - nyaranoW rryorograpns tmension Tor AulooesKw uvn vuavzu iy oy,vuTooesK, mc. vcuLu Hyd. No. 15 DA-8 Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.160 ac Runoff. coeff. Intensity = 6.695 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 ® Hyd No. 15 DA-8 Hyd. No. 15 -- 10 Year Wednesday, 02 / 20 / 2019 = 0.461 cfs = 0.08 hrs = 138 cuft = 0.43 = 5.00 min = 1/1 Q (cfs) 0.50 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0.10 0.05 000 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) Hydrograph Report 55 Hydraflow Hydrographs Extension for Autodesk® Civil 3DO2019 by Autodesk, Inc. v2020 Hyd. No. 16 ' DA-9 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume ' Drainage area = 0.340 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 0.0 Hyd No. 16 DA-9 Hyd. No. 16 — 2 Year Wednesday,0212012019 = 0.759 cfs = 0.08 hrs = 228 cuft = 0.43 = 5.00 min = 1/1 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) Hydrograph Report 56 Hydraflow Hydrographs Extension for Autodesk® Civil 3DV 2019 by Autodesk, Inc. v2020 Hyd. No. 16 DA-9 Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.340 ac Runoff coeff. Intensity = 6.695 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact 0.0 0.0 ® Hyd No. 16 DA-9 Hyd. No. 16 -- 10 Year Wednesday, 02120 / 2019 = 0.979 cfs = 0.08 hrs = 294 cult = 0.43 = 5.00 min = 1/1 Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 000 0.0 0.1 0.1 0.1 0.1 01 0.1 0.2 0.2 Time (hrs) Hydrograph Report 57 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 i Hyd. No. 17 - DA-10 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.380 ac Runoff coeff. Intensity = 5.193 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact � �=�M 0.0 0.0 0.0 — Hyd No. 17 DA-10 Hyd. No. 17 -- 2 Year Wednesday, 02 / 20 / 2019 = 0.849 cfs = 0.08 hrs = 255 cuft = 0.43 = 5.00 min = 1/1 Q (Cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 Time (hrs) Hydrograph Report 58 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 17 DA-10 Hydrograph type = Rational Peak discharge = 1.094 cfs Storm frequency = 10 yrs Time to peak = 0.08 hrs Time interval = 1 min Hyd. volume = 328 cuft Drainage area = 0.380 ac Runoff coeff. = 0.43 Intensity = 6.695 in/hr Tc by User = 5.00 min OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (cfs) 2.00 1.00 DA-10 Hyd. No. 17 — 10 Year Q (cfs) 2.00 1.00 0.00 V1 1 1 1 1 1 1 1 1 ti 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 ® Hyd No. 17 Time (hrs) Hydrograph Report 59 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autndesk, Inc. v2020 Hyd. No. 18 DA-1 Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.870 ac Runoff coeff. Intensity = 4.180 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 2.00 1.00 0.00 r 0.0 0.0 Hyd No. 18 DA-1 Hyd. No. 18 — 2 Year Wednesday, 02 / 2012019 = 1.091 cfs = 0.17 hrs = 655 cult = 0.3 = 10.00 min = 1/1 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.3 Q (cfs) 2.00 1.00 fit- 0.00 0.3 Time (hrs) Hydrograph Report I - Hydraflow Hydrographs Extension for Autodesk® Civil 30.0 2019 by Autodesk, Inc. v2020 Hyd. No. 18 DA-1 ` Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 0.870 ac Runoff coeff. Intensity = 5.392 in/hr Tc by User OF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 2.00 1.00 0.00 —" 0.0 0.0 ® Hyd No. 18 DA-1 Hyd. No. 18 -- 10 Year Wednesday, 02 / 20 / 2019 = 1.407 cfs = 0.17 hrs = 844 cuft = 0.3 = 10.00 min = 1/1 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.3 Q (cfs) 2.00 1.00 0.00 0.3 Time (hrs) Hydrograph Report 61 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 32 OFFSITE-EX5 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 8 - OFFSITE Section type Reach length = 200.0 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 7.253 Rating curve m Ave. velocity = 2.47 fUs Routing coeff. Modified Aft -Kin routing method used. Q (cfs) 8.00 .M 4.00 MA OFFSITE-EX5 Hyd. No. 32 — 2 Year 0.00 — 0.0 0.0 0.0 0.1 0.1 0.1 — Hyd No. 32 Hyd No. 8 0.1 0.1 0.1 Wednesday, 02 / 2012019 = 6.886 cfs = 0.10 hrs = 2,477 cuft = Circular = 0.9 % = 2.0 ft = 0.0 ft = 1.250 = 0.6336 Q (cfs) 8.00 �1 4.00 2.00 0.00 0.2 0.2 0.2 0.2 0.2 0.2 Time (hrs) Hydrograph Report 62 nyaranow rtyarographs txtension Tor AutoaesKU UIVII 3UVZU1U oy AufoaesK, Inc. vZuzu - Hyd. No. 32 OFFSITE-EX5 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 8 - OFFSITE Section type Reach length = 200.0 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 7.253 Rating curve m Ave. velocity = 3.19 fUs Routing coeff. Modified Att-Kin routing method used. Q (cfs) 12.00 10.00 M .M 4.00 2.00 OFFSITE-EX5 Hyd. No. 32 - 10 Year 0.00 0.0 0.0 0.0 0.1 0.1 0.1 ® Hyd No. 32 ® Hyd No. 8 0.1 0.1 Wednesday, 02 / 2012019 = 9.345 cfs = 0.10 hrs = 3,165 cuft = Circular = 0.9 % = 2.0 ft = 0.0 ft = 1.250 = 0.7483 Q (cfs) 12.00 10.00 E:111if, GY411 4.00 2.00 0.00 0.1 0.2 0.2 0.2 0.2 0.2 Time (hrs) Hydrograph Report 63 - Hydraflow Hydragraphs Extension for Autodesk(D Civil 3D®2019 by Aulodesk, Inc. v2020 Hyd. No. 30 EX6-EX5 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 1 - DA-EX6 Section type Reach length = 48.0 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 13.084 Rating curve m it Ave. velocity = 2.93 fUs Routing coeff. Modified Att-Kin routing method used. Q (cfs) 4.00 3.00 2.00 1.00 0.00 = 0.0 0.0 0.0 ® Hyd No. 30 EX6-EX5 Hyd. No. 30 -- 2 Year 0.1 0.1 ® Hyd No, 1 Wednesday, 02 / 20 12019 = 3.797 cfs = 0.10 hrs = 1,120 cuft = Circular = 3.5 % = 1.3ft = 0.0 ft = 1.250 = 1.3923 0.1 0.1 0.1 0.1 0.2 0.2 3.00 2.00 1.00 — N- 0.00 0.2 Time (hrs) Hydrograph Report 64 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 30 EX6-EX5 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 1 - DA-EX6 Section type Reach length = 48.0 ft Channel slope Manning's In = 0.012 Bottom width Side slope = 0.0:1 Max. depth ' Rating curve x = 13.084 Rating curve m Ave. velocity = 3.78 fUs Routing coeff. Modified Att-Kin routing method used. Q (Cfs) 5.00 4.00 3.00 01111 1.00 EX6-EX5 Hyd. No. 30 -- 10 Year 0.00 0.0 0.0 0.0 0.1 0.1 e Hyd No. 30 ® Hyd No. 1 0.1 0.1 0.1 0.1 Wednesday, 02/20/2019 = 4.928 cfs = 0.10 hrs = 1,442 cuft = Circular = 3.5 % = 1.3ft = 0.0 ft = 1.250 = 1.4942 Q (cfs) 5.00 3.00 WA1411I EKiP] N 0.00 0.2 0.2 0.2 Time (hrs) Hydrograph Report 65 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 31 EX5A-EX5 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 2 - DA-EX5A Section type Reach length = 40.0 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 12.303 Rating curve m Ave. velocity = 0.80 ftls Routing coeff. Modred Att-Kin routing method used. AILMN 11 11 11 1 1 1 1 Wednesday, 02/20/2019 = 0.954 cfs = 0.10 hrs = 309 cuft = Circular = 3.1 % = 1.3 ft = 0.0 ft = 1.250 = 0.8596 Hydrograph Report 66 - . Hydrafiow Hydrographs Extension for Aulodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 ' Hyd. No. 31 EX5A-EX5 Hydrograph type = Reach Peak discharge = 1.268 cfs Storm frequency = 10 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 397 cuft Inflow hyd. No. = 2 - DA-EX5A Section type = Circular Reach length = 40.0 ft Channel slope = 3.1 % Manning's n = 0.012 Bottom width = 1.3 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 12.303 Rating curve m = 1.250 Ave. velocity = 1.04 ft/s Routing coeff. = 0.9857 Modified Att-Kin routing method used Q (cfs) 2.00 1.00 EX5A-EX5 Hyd. No. 31 — 10 Year 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 — Hyd No. 31 — Hyd No. 2 Q (cfs) 2.00 1.00 --11- 0.00 0.2 Time (hrs) Hydrograph Report 67 Hydraflow Hydrographs Extension for Autodesk® Civil 30@ 2019 by Autodesk, Inc. v2020 Wednesday, 02120 / 2019 Hyd. No. 34 EX5 Combined Hydrograph type = Combine Peak discharge = 11.64 cfs Storm frequency = 2 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 3,906 cuft Inflow hyds. = 30, 31, 32 Contrib. drain. area = 0.000 ac EX5 Combined Q (Cfs) Hyd. No. 34 -- 2 Year Q (cfs) 12.00 12.00 10.00 10.00 8.00 8.00 6.00 6.00 4.00 4.00 Oor 2.00 2.00 0.00 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 Time (hrs) - Hyd No. 34 -Hyd No. 30 -Hyd No. 31 -Hyd No. 32 Hydrograph Report s$ Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02120 / 2019 Hyd. No. 34 EX5 Combined Hydrograph type = Combine Peak discharge = 15.54 cfs Storm frequency = 10 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 5,004 cuft Inflow hyds. = 30, 31, 32 Contrib. drain. area = 0.000 ac Q (cfs) 18.00 15.00 12.00 • M . m 3.00 EX5 Combined Hyd. No. 34 -- 10 Year Q (cfs) 18.00 15.00 12.00 M M 3.00 0.00 I I I I I i 1 — 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 Time (hrs) — Hyd No. 34 —Hyd No. 30 —Hyd No. 31 —Hyd No. 32 Hydrograph Report 69 Hydraflow Hydrographs Extension for Autodesk® Civil 3CO 2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 '- Hyd. No. 35 EX5-EX4 Hydrograph type = Reach Peak discharge = 11.72 cfs Storm frequency = 2 yrs Time to peak = 0.12 hrs Time interval = 1 min Hyd. volume = 4,050 cuft Inflow hyd. No. = 34 - EX5 Combined Section type = Circular Reach length = 130.0 ft Channel slope = 1.8 % Manning's n = 0.012 Bottom width = 2.0 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 10.006 Rating curve m = 1.250 Ave. velocity = 3.70 ft/s Routing coeff. = 1.0332 Modified Att-Kin routing method used Q (cfs) 12.00 10.00 1:111p1 go 4.00 2.00 0.00 0.0 0.0 0.0 0.1 - Hyd No. 35 EX5-EX4 Hyd. No. 35 -- 2 Year 0.1 0.1 0.1 Hyd No. 34 Q (cfs) 12.00 111161111A1 We .5 4.00 FA1I11 0.00 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 Time (hrs) Hydrograph Report 70 Hydraflow Hydmgraphs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 35 EX5-EX4 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 34 - EX5 Combined Section type - Reach length = 130.0 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth ` Rating curve x = 10.006 Rating curve m _ Ave. velocity = 4.95 ft/s Routing coeff. Modified Att-Kin routing method used Q (cfs) 18.00 15.00 12.00 • KI 3.00 EX5-EX4 Hyd. No. 35 - 10 Year 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 - Hyd No. 35 Hyd No. 34 Wednesday, 02/20/2019 = 16.00 cfs = 0.12 hrs = 5,166 cuft = Circular = 1.8 % = 2.0 ft = 0.0 ft = 1.250 = 1.1760 Q (cfs) 18.00 15.00 12.00 • IX 3.00 'I 10.00 0.2 0.2 0.2 0.2 0.2 Time (hrs) Hydrograph Report 71 - Hydraflow Hydrographs Extension for Autodesk® Civil 3DO 2019 by Aulodesk. Inc. v2020 Hyd. No. 36 EX4A-EX4 " Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 5 - DA-EX4A Section type Reach length = 40.0 ft Channel slope Manning's n = 0.120 Bottom width Side slope = 0.0:1 Max. depth " Rating curve x = 1.230 Rating curve m Ave. velocity = 2.06 fUs Routing coeff. Modified Att-Kin routing method used. Q (cfs) 3.00 1.00 0.00 0.0 0.0 0.0 — Hyd No. 36 EX4A-EX4 Hyd. No. 36 — 2 Year 0.1 0.1 Hyd No. 5 Wednesday, 02/20/2019 = 2.653 cfs = 0.10 hrs = 788 cult = Circular = 3.1 % = 1.3 ft = 0.0 ft = 1.250 = 1.3183 0.1 0.1 0.1 0.1 0.2 0.2 Q (cfs) 3.00 WA1UI 1.00 --b- 0.00 0.2 Time (hrs) Hydrograph Report 72 Hydraflow Hydrographs Extension for Autodesk® Civil 3DID 2019 by Autodesk, Inc. v2020 Hyd. No. 36 EX4A-EX4 I` Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 5 - DA-EX4A Section type Reach length = 40.0 ft Channel slope Manning's n = 0.120 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 1.230 Rating curve m Ave. velocity = 2.66 ft/s Routing coeff. Modified Att-Kin routing method used Q (cfs) 4.00 3.00 1.00 0.00 if I' 0.0 0.0 0.0 — Hyd No. 36 EX4A-EX4 Hyd. No. 36 — 10 Year 0.1 0.1 Hyd No. 5 Wednesday, 02 / 20 / 2019 = 3.453 cfs = 0.10 hrs = 1,015 cuft = Circular = 3.1 % = 1.3 ft = 0.0 ft = 1.250 = 1.4275 0.1 0.1 0.1 0.1 0.2 0.2 Q (Cfs) 4.00 3.00 2.00 1.00 --Ai- 0.00 0.2 Time (hrs) Hydrograph Report 73 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 37 r EX4 Combined Hydrograph type = Combine Peak discharge = 14.34 cfs ' Storm frequency = 2 yrs Time to peak = 0.12 hrs Time interval = 1 min Hyd. volume = 5,236 cult Inflow hyds. = 4, 35, 36 Contrib. drain. area = 0.350 ac EX4 Combined Q (cfs) Hyd. No. 37 -- 2 Year Q (cfs) 15.00 15.00 12.00 12.00 9.00 9.00 6.00 6.00 3.00 3.00 0.00 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 Time (hrs) — Hyd No. 37 —Hyd No. 4 —Hyd No. 35 —Hyd No. 36 Hydrograph Report 74 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 37 EX4 Combined Hydrograph type = Combine Peak discharge Storm frequency = 10 yrs Time to peak '. Time interval = 1 min Hyd. volume Inflow hyds. = 4, 35, 36 Contrib. drain. area Wednesday, 02120 = 19.28 cfs = 0.12 hrs = 6,695 cuft = 0.350 ac / 2019 Q (cfs) EX4 Combined Hyd. No. 37 -- 10 Year Q (cfs) 21.00 21.00 18.00 18.00 15.00 15.00 12.00 12.00 9.00 9.00 6.00 6.00 3.00 3.00 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 - Hyd No. 37 -Hyd No. 4 -Hyd No. 35 -Hyd 0.00 0.2 0.2 0.2 Time (hrs) No. 36 Hydrograph Report 73 A Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Thursday, 02 / 21 12019 Hyd. No. 38 EX4-3 Hydrograph type = Reach Peak discharge = 14.54 cfs Storm frequency = 2 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 5,368 cuft Inflow hyd. No. = 37 - EX4 Combined Section type = Circular Reach length = 57.7 ft Channel slope = 4.3 % Manning's n = 0.012 Bottom width = 2.0 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 15.649 Rating curve m = 1.250 Ave. velocity = 4.56 ft/s Routing coeff. = 1.4955 Modified Att-Kin routing method used. Q (cfs) 15.00 12.00 M . of 3.00 0.00 0 1 2 — Hyd No. 38 EX4-3 Hyd. No. 38 -- 2 Year 3 4 5 6 7 Hyd No. 37 Q (cfs) 15.00 12.00 • 1i . 1i 3.00 8 9 10 11 12 13 14 15 Time (min) 74 A Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3DS 2019 by Autodesk, Inc. v2020 Hyd. No. 38 EX4-3 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 37 - EX4 Combined Section type Reach length = 57.7 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 15.649 Rating curve m Ave. velocity = 6.14 fUs Routing coeff. Thursday, 02 / 21 ! 2019 = 19.44 cfs = 7 min = 6,900 cuft = Circular = 4.3 % = 2.0 ft = 0.0 ft = 1.250 = 1.5989 Modified Aft -Kin routing method used. EX4-3 Q (cfs) Hyd. No. 38 -- 10 Year Q (cfs) 21.00 21.00 18.00 18.00 15.00 15.00 12.00 12.00 9.00 9.00 IF 6.00 6.00 3.00 3.00 0.00 0.00 0 1 2 3 4 5 6 7 8 9 10 11 12 — Hyd No. 38 —Hyd No. 37 13 14 15 Time (min) Hydrograph Report 75 - f Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 ` Hyd. No. 39 3 Combined Hydrograph type = Combine Peak discharge = 14.62 cfs Storm frequency = 2 yrs Time to peak = 0.13 hrs Time interval = 1 min Hyd. volume = 5,424 cuft Inflow hyds. = 6, 38 Contrib. drain. area = 0.050 ac Q (cfs) 15.00 12.00 9.00 6.00 3.00 0.00 0.0 0.0 0.0 0.1 — Hyd No. 39 3 Combined Hyd. No. 39 -- 2 Year 0.1 0.1 0.1 — Hyd No. 6 0.1 Q (cfs) 15.00 12.00 M 3.00 — 0.00 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 — Hyd No. 38 Time (hrs) Hydrograph Report 76 Hydraflow Hydrographs Extension for Autodesk® Civil 3D0 2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 12019 Hyd. No. 39 3 Combined Hydrograph type = Combine Peak discharge = 19.59 cfs Storm frequency = 10 yrs Time to peak = 0.12 hrs Time interval = 1 min Hyd. volume = 6,972 cuft Inflow hyds. = 6, 38 Contrib. drain. area = 0.050 ac Q (cfs) 21.00 18.00 15.00 12.00 • 11 . MI K 11 3 Combined Hyd. No. 39 — 10 Year Q (cfs) 21.00 18.00 15.00 12,00 • 11 3.00 0.00 r I 1 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 Time (hrs) — Hyd No. 39 —Hyd No. 6 —Hyd No. 38 77 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 31)®2019 by Autodesk, Inc. v2020 Hyd. No. 40 3-2 Hydrograph type = Reach Peak discharge ' Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 39 - 3 Combined Section type " Reach length = 115.1 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 7.369 Rating curve m Ave. velocity = 4.65 fUs Routing coeff. Modified Aft -Kin routing method used. Q (Cfs) 15.00 i9911111111 • e� 3.00 0.00 0.0 0.0 Hyd No. 40 3-2 Hyd. No. 40 — 2 Year 0.1 0.1 Hyd No. 39 Wednesday, 02 / 20 / 2019 = 14.64 cfs = 0.15 hrs = 5,608 cuft = Circular = 1.0 % = 2.0 ft = 0.0 ft = 1.250 = 1.2049 0.1 0.2 0.2 0.2 Q (cfs) 15.00 EVAUX �1 �1 3.00 x 0.00 0.3 Time (hrs) Hydrograph Report Hydraflow Hydrographs Extension for AutodeskO Civil 3DO 2019 by Autodesk, Inc. v2020 Hyd. No. 40 3-2 Hydrograph type = Reach Peak discharge " Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 39 - 3 Combined Section type ' Reach length = 115.1 ft Channel slope Manning's In = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 7.369 Rating curve m Ave. velocity = 6.23 ft/s Routing coeff. Modified Att-Kin routing method used. Q (cfs) 21.00 15.00 WAIDI • m ma 3.00 0.00 0.0 0.0 — Hyd No. 40 3-2 Hyd. No. 40 — 10 Year 0.1 0.1 0.1 Hyd No. 39 78 Wednesday, 02 / 20 / 2019 = 21.09 cfs = 0.13 hrs = 7,212 cuft = Circular = 1.0 % = 2.0 ft = 0.0 ft = 1.250 = 1.3400 0.2 0.2 0.2 Q (cfs) 21.00 18.00 15.00 12.00 &M 3.00 0-=-- 0.00 0.3 Time (hrs) ' Hydrograph Report 79 Hydraflow Hydrographs Extension for Autodesk® Civil 3002019 by Autodesk, Inc. v2020 Wednesday, 02120 / 2019 Hyd. No. 41 2 Combined Hydrograph type = Combine Peak discharge = 15.34 cfs Storm frequency = 2 yrs Time to peak = 0.13 hrs Time interval = 1 min Hyd. volume = 6,219 cuft Inflow hyds. = 7, 40 Contrib. drain. area = 0.490 ac Q (cfs) 18.00 iLXIYI 12.00 M [: lild 3.00 0.00 ' ' 0.0 0.0 — Hyd No. 41 2 Combined Hyd. No. 41 — 2 Year 0.1 0.1 — Hyd No. 7 0.1 0.2 Hyd No. 40 0.2 0.2 Q (cfs) 18.00 15.00 12.00 . 1� 3.00 =b.L- 0.00 0.3 Time (hrs) Hydrograph Report 80 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 2012019 ` Hyd. No. 41 2 Combined Hydrograph type = Combine Peak discharge = 22.14 cfs ' Storm frequency = 10 yrs Time to peak = 0.13 hrs Time interval = 1 min Hyd. volume = 7,999 cuft Inflow hyds. = 7, 40 Contrib. drain. area = 0.490 ac Q (Cfs) 24.00 �4011il, 16.00 12.00 90 4.00 0.00 `� 0.0 0.0 — Hyd No. 41 2 Combined Hyd. No. 41 -- 10 Year 0.1 0.1 Hyd No. 7 0.1 0.2 — Hyd No. 40 0.2 0.2 Q (Cfs) 24.00 20.00 16.00 12.00 4.00 M-t- 0.00 0.3 Time (hrs) 81 Hydrograph Report I Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 42 i� 2-1A Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 7 - DA-2 Section type Reach length = 46.0 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 7.445 Rating curve m '. Ave. velocity = 0.65 ft/s Routing coeff. Modified Att-Kin routing method used. Q (cfs) 3.00 r M 1.00 0.00 it 0.0 0.0 0.0 — Hyd No. 42 2-1 A Hyd. No. 42 -- 2 Year 0.1 0.1 0.1 Hyd No. 7 Wednesday, 02/20/2019 = 1.856 cfs = 0.10 hrs = 646 cuft = Circular = 1.0 % = 2.0 ft = 0.0 ft = 1.250 = 0.6916 0.1 0.1 0.1 0.2 0.2 0.2 0.2 Q (cfs) 3.00 2.00 1.00 =='- 0.00 0.2 Time (hrs) Hydrograph Report I - Hydraflow Hydrographs Extension for Autodesk® Civil 308 2019 by Autodesk, Inc. v2020 Hyd. No. 42 2-1 A Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 7 - DA-2 Section type Reach length = 46.0 ft Channel slope Manning's In = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 7.445 Rating curve m Ave. velocity = 0.84 ft/s Routing coeff. Modified Att-Kin routing method used. Q (cfs) 3.00 2.00 1.00 0.00 ; ' 0.0 0.0 0.0 — Hyd No. 42 2-1 A Hyd. No. 42 -- 10 Year 0.1 0.1 0.1 Hyd No. 7 Wednesday, 02 / 20 / 2019 = 2.502 cfs = 0.10 hrs = 826 cuft = Circular = 1.0 % = 2.0 ft = 0.0 ft = 1.250 = 0.8106 0.1 0.1 0.1 0.2 0.2 0.2 Q (cfs) 3.00 fWAIIIIIII] 1.00 --V- 0.00 0.2 Time (hrs) Hydrograph Report 83 " Hydraflow Hydrographs Extension for Autodesk® Civil 30@ 2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 43 1A Flow into Splitter Hydrograph type = Combine Peak discharge = 16.71 cfs Storm frequency = 2 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 6,865 cuft Inflow hyds. = 41, 42 Contrib. drain. area = 0.000 ac 1A Flow into Splitter Q (cfs) Hyd. No. 43 -- 2 Year Q (cfs) 18.00 18.00 15.00 15.00 12.00 12.00 9.00 9.00 6.00 6.00 3.00 3.00 0.00 0.00 0 2 4 6 8 10 12 14 16 Time (min) — Hyd No. 43 —Hyd No. 41 —Hyd No. 42 84 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 02 120 / 2019 Hyd. No. 43 1A Flow into Splitter Hydrograph type = Combine Peak discharge = 23.83 cfs Storm frequency = 10 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 8,825 cuft Inflow hyds. = 41, 42 Contrib. drain. area = 0.000 ac 1A Flow into Splitter Q (cfs) Hyd. No. 43 — 10 Year Q (cfs) 24.00 24.00 20.00 20.00 16.00 16.00 If 12.00 12.00 8.00 8.00 4.00 4.00 0.00 0.00 0 2 4 6 8 10 12 14 16 Time (min) — Hyd No. 43 —Hyd No. 41 —Hyd No. 42 Hydrograph Report 85 Hydraflow Hydrographs Extension for Autodesk® Civil 300 2019 by Autodesk, Inc. v2020 Hyd. No. 45 Structure 1A Splitter Hydrograph type = Reservoir Peak discharge Storm frequency = 2 yrs Time to peak . Time interval = 1 min Hyd. volume Inflow hyd. No. = 43 - 1 A Flow into Splitter Max. Elevation Reservoir name it = Structure 1A Max. Storage Storage Indication method used. l Structure 1ASplitter Q (cfs) Hyd. No. 45 -- 2 Year I 1 d.uu 15.00 12.00 9.00 6.00 3.00 riLTP Wednesday, 02/2012019 = 16.83 cfs = 0.13 hrs = 6,869 cult = 483.39 ft = 29 cult Q (cfs) 18.00 15.00 12.00 &XIIIA1 3.00 R $ i7 0.0 0.0 0.1 0.1 0.1 0.2 0.2 0.2 0.3 — Hyd No. 45 — Hyd No. 43 .__ Total storage used = 29 cuft 0.3 Time (hrs) Hydrograph Report 86 Hydraflow Hydrographs Extension for Autodesk® Civil 3DO2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 45 Structure 1A Splitter Hydrograph type = Reservoir Peak discharge = 23.69 cfs Storm frequency = 10 yrs Time to peak = 0.13 hrs Time interval = 1 min Hyd. volume = 8,837 cuft Inflow hyd. No.. = 43 - 1A Flow into Splitter Max. Elevation = 484.14 ft Reservoir name = Structure 1A Max. Storage = 39 cuft Storage Indication method used Q (cfs) 24.00 20.00 16.00 12.00 0.00 a 0.0 0.0 — Hyd No. 45 Structure 1A Splitter Hyd. No. 45 -- 10 Year 0.1 0.1 0.1 0.2 0.2 0.2 0.3 Hyd No.43 =_._ Total storage used = 39 cult Q (cfs) 24.00 20.00 16.00 4.00 1 0.00 0.3 Time (hrs) Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 '1 Hyd. No. 45 `( Structure 1A Splitter 87 Wednesday, 02 / 20 / 2019 Hydrograph type = Reservoir Peak discharge = 35.44 cfs Storm frequency = 100 yrs Time to peak = 0.13 hrs j... Time interval = 1 min Hyd. volume = 11,876 cuft Inflow hyd. No. = 43 - 1A Flow into Splitter Max. Elevation = 487.66 ft I Reservoir name = Structure 1A Max. Storage = 63 cuft Storage Indication method used. Structure I Splitter Q (cfs) Hyd. No. 45 -- 100 Year Q (cfs) 40.00 30.00 20.00 10.00 m 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 _ Time (hrs) — Hyd No. 45 — Hyd No. 43 ____' Total storage used = 63 cult Pond Report BS Hydraflow Hydrographs Extension for Autodesk® Civil 3DS 2019 by Autodesk, Inc. v2020 Wednesday, 02 ! 20 / 2019 Pond No. 1 - Structure 1A Pond Data Contours -User-defined contour areas. Conic method used for volume calculation. Begining Elevation = 480.50 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sgft) Incr. Storage (cult) Total storage (cuft) 0.00 480.50 13 0 0 1.00 481.75 13 13 13 2.00 482.75 13 13 25 3.00 483.75 13 13 38 4.00 484.75 13 13 50 5.00 485.75 13 13 63 6.00 486.75 13 13 75 7.16 487.66 13 15 90 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in) = 12.00 24.00 0.00 0.00 Crest Len (ft) = 0.00 0.00 0.00 0.00 Span (in) = 12.00 24.00 0.00 0.00 Crest EL (ft) = 0.00 0.00 0.00 0.00 No. Barrels = 1 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert El. (ft) = 480.50 481.50 0.00 0.00 Weir Type = - - - - Length (ft) = 39.90 0.00 0.00 0.00 Multi -Stage = No No No No Slope (%) = 0.63 0.00 0.00 n/a N-Value = .012 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Contour) Multi -Stage = n/a No No No TIN Elev. (ft) = 0.00 Note: Culvwucrinnw ouNowsare analyzed underinlet(ic) and outlet(oc) mrdml. Weirriserscheckedfarodfimmnditims(ic)andwbmMence(s). Stage (ft) 8.00 6.00 mom 2.00 0.00 r 0.00 4.00 Total Q Stage / Discharge 8.00 12.00 16.00 20.00 24.00 28.00 32.00 36.00 40.00 44.00 Elev (ft) 488.50 486.50 MIMI 482.50 1 480.50 48.00 Discharge (cfs) Hydrograph Report q Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 46 IA-1 Hydrograph type = Diversion1 Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hydrograph = 45 - Structure 1A Splitter 2nd diverted hyd. Diversion method = Pond - Structure 1A Pond structure Q (cfs) 18.00 15.00 12.00 • M 3.00 0.00 r 0 2 4 Hyd No. 46 -- Pond outlet 1A-1 Hyd. No. 46 — 2 Year 6 8 10 12 — Hyd No. 45 -- Inflow Thursday, 02 / 2112019 = 11.48 cfs = 8 min = 3,687 cuft = 47 = Culy/Orf B Q (cfs) 18.00 15.00 12.00 MO MI 3.00 0.00 14 16 18 Time (min) Hyd No. 47 -- 45 minus 46 Hydrograph Report M Hydrallow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 46 1 A-1 Hydrograph type = Diversion'! Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hydrograph = 45 - Structure I Splitter 2nd diverted hyd Diversion method = Pond -Structure 1A Pond structure Q (cfs) 24.00 001 11 16.00 12.00 : 11 01 0.00 0 2 4 — Hyd No. 46 -- Pond outlet 1 A-1 Hyd. No. 46 -- 10 Year 6 8 10 12 — Hyd No. 45 -- Inflow Thursday, 02 / 21 / 2019 = 17.37 cfs = 8 min = 5,366 cuft = 47 = Culy/Orf B Q (cfs) 24.00 20.00 16.00 12.00 4.00 0.00 14 16 18 Time (min) Hyd No. 47 — 45 minus 46 . Hydrograph Report 91 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Thursday, 02 / 2112019 Hyd. No. 47 Biofilter Hydrograph type = Diversion2 Peak discharge = 5.350 cfs Storm frequency = 2 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 10,029 cuft Inflow hydrograph = 45 - Structure 1A Splitter 2nd diverted hyd. = 46 Diversion method = Pond - Structure 1A Pond structure = Culy/Orf B Biofilter Q (cfs) Hyd. No. 47 -- 2 Year Q (cfs) 18.00 18.00 15.00 15.00 12.00 12.00 9.00 9.00 6.00 6.00 Oz 3.03 3.00 0.00 0.00 0 2 4 6 8 10 12 14 16 18 Time (min) — Hyd No. 47 -- Qin -Pond outlet —Hyd No. 45 -- Inflow —Hyd No. 46 M Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 47 Biofilter Hydrograph type = Diversion2 Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hydrograph = 45 -Structure 1A Splitter 2nd diverted hyd Diversion method = Pond -Structure 1A Pond structure Q (cfs) 24.00 16.00 12.00 4.00 0.00 r 0 2 4 6 — Hyd No. 47 — Qin - Pond outlet Biofilter Hyd. No. 47 — 10 Year 8 10 — Hyd No. 45 — Inflow Thursday, 0212112019 = 6.323 cfs = 8 min = 10,327 cult = 46 = Culy/Orf B 12 14 Hyd No. 46 Ic Q (Cfs) 24.00 20.00 511-10b1 12.00 i 4.00 ... 1- 0.00 18 Time (min) Hydrograph Report 93 Hydraflow Hydrographs Extension for Autodesk® Civil MOD 2019 by Autodesk, Inc. v2020 _ Hyd. No. 47 Biofilter Hydrograph type = Diversion2 Peak discharge ' Storm frequency = 100 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hydrograph = 45 - Structure 1A Splitter 2nd diverted hyd Diversion method = Pond -Structure 1A Pond structure Q (cfs) x 40.00 30.00 20.00 10.00 0.00 = 0 1 2 3 4 5 — Hyd No. 47 -- Gin - Pond outlet Biofilter Hyd. No. 47 -- 100 Year 6 7 8 9 Hyd No. 45 — Inflow Thursday, 02/21/2019 = 8.229 cfs = 8 min = 10,745 cuft = 46 = Culy/Orf B 10 11 12 13 — Hyd No. 46 14 Q (cfs) 40.00 30.00 20.00 10.00 =a-'- 0.00 15 Time (min) Hydrograph Report 94 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 52 10-9 Hydrograph type = Reach Peak discharge ' Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 17 - DA-10 Section type ' Reach length = 110.7 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 13.146 Rating curve m Ave. velocity = 1.08 ftls Routing coeff. Modified Att-Kin routing method used. Wednesday, 02 / 20 / 2019 = 0.708 cfs = 0.10 hrs = 273 cuft = Circular = 3.8 % = 1.0 ft = 0.0 ft = 1.250 = 0.5359 10-9 Q (cfs) Hyd. No. 52 -- 2 Year Q (cfs) 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 000 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 000 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 Time (hrs) - Hyd No. 52 -Hyd No. 17 Hydrograph Report 95 Hydraflow Hydrographs Extension for Autodeska0 Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 ! 20 / 2019 Hyd. No. 52 �10-9 Hydrograph type = Reach Peak discharge = 0.974 cfs ' Storm frequency = 10 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 348 cuft Inflow hyd. No. = 17 - DA-10 Section type = Circular Reach length = 110.7 ft Channel slope = 3.8 % - Manning's n = 0.012 Bottom width = 1.0 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 13.146 Rating curve m = 1.250 Ave. velocity = 1.39 fUs Routing coeff. = 0.6412 Modified Att-Kin routing method used Q (cfs) 2.00 1.00 0.00 ' 0.0 0.0 0.0 0.1 — Hyd No. 52 10-9 Hyd. No. 52 -- 10 Year 0.1 0.1 0.1 0.1 — Hyd No. 17 Q (cfs) 2.00 1.00 ' 10.00 0.1 0.2 0.2 0.2 0.2 0.2 0.2 Time (hrs) Hydrograph Report 96 Hydraflow Hydrographs Extension for Autodesk® Civil 3DS 2019 by Autodesk, Inc. v2020 Hyd. No. 53 9 Combined Hydrograph type = Combine Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 16, 52 Contrib. drain. area Wednesday, 02 / 20 / 2019 = 1.316 cfs = 0.10 hrs = 501 cuft = 0.340 ac 1 Q (cfs) 9 Combined Hyd. No. 53 — 2 Year Q (cfs) 2.00 2.00 1.00 1.00 or 0.00 0.00 0.0 0.0 0.0 0.1 0.1 DA 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 Time (hrs) — Hyd No. 53 —Hyd No. 16 —Hyd No. 52 Hydrograph Report 97 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 53 9 Combined Hydrograph type = Combine Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 16, 52 Contrib. drain. area Q (Cfs) 2.00 1.00 0.00 0.0 0.0 0.0 Hyd No. 53 9 Combined Hyd. No. 53 -- 10 Year 0.1 0.1 0.1 — Hyd No. 16 0.1 0.1 0.1 — Hyd No. 52 Wednesday, 02 / 20 / 2019 = 1.757 cfs = 0.10 hrs = 642 cuft = 0.340 ac 0.2 0.2 0.2 0.2 Q (Cfs) 2.00 1.00 0,00 0.2 Time (hrs) Hydrograph Report 98 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 55 r 9-8 Hydrograph type = Reach Peak discharge r Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 53 - 9 Combined Section type Reach length = 57.3 ft Channel slope - Manning's n = 0.012 Bottom width Side slope I = 0.0:1 Max. depth Rating curve x = 9.824 Rating curve m Ave. velocity = 1.68 ft/s Routing coeff. r, Modified Att-Kin routing method used. Q (efs) 2.00 1.00 9-8 Hyd. No. 55 — 2 Year Wednesday, 02 / 20 / 2019 = 1.319 cfs = 0.10 hrs = 519 cuft = Circular = 2.2 % = 1.0 ft = 0.0 ft = 1.250 = 1.0460 0.00 I ' 0.0 0.0 0.1 0.1 0.1 0.2 02 0.2 Hyd No. 55 — Hyd No. 53 Q (cfs) 2.00 1.00 --.&- 0.00 0.3 Time (hrs) Hydrograph Report Ir Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 55 9-8 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 53 - 9 Combined Section type Reach length = 57.3 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 9.824 Rating curve m Ave. velocity = 2.24 fUs Routing coeff. Modified Att-Kin routing method used. Q (cfs) 2.00 1.00 0.00 0.0 0.0 0.0 0.1 — Hyd No. 55 9-8 Hyd. No. 55 — 10 Year 0.1 0.1 0.1 0.1 — Hyd No, 53 Wednesday, 02/20/2019 = 1.802 cfs = 0.10 hrs = 663 cuft = Circular = 2.2 % = 1.0ft = 0.0 ft = 1.250 = 1.1882 Q (Cfs) 2.00 1.00 0.00 0.1 0.2 0.2 0.2 0.2 0.2 0.2 Time (hrs) Hydrograph Report 100 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 56 8 Combined r. Hydrograph type = Combine Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 15, 55 Contrib. drain. area Q (cfs) 2.00 1.00 0.00 ri 1 1 1 0.0 0.0 0.0 0.1 — Hyd No. 56 8 Combined Hyd. No. 56 -- 2 Year 0.1 0.1 0.1 — Hyd No. 15 0.1 0.1 0.2 0.2 — Hyd No. 55 Wednesday, 02 / 20 12019 = 1.605 cfs = 0.10 hrs = 626 cult = 0.160 ac 0.2 0.2 0.2 0.2 Q (cfs) 2.00 1.00 0.00 0.3 Time (hrs) Hydrograph Report 101 Hydrallow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2020 Wednesday, 09 12512019 Hyd. No. 56 8 Combined Hydrograph type = Combine Peak discharge = 2.170 cfs Storm frequency = 10 yrs Time to peak = 6 min Time interval = 1 min Hyd. volume = 801 cuft Inflow hyds. = 15, 55 Contrib. drain. area = 0.160 ac Q (cfs) 3.00 2.00 1.00 0.00 — 0 1 2 Hyd No 56 8 Combined Hyd. No. 56 -- 10 Year 3 4 5 6 — Hyd No. 15 7 8 9 — Hyd No. 55 Q (cfs) 3.00 2.00 1.00 •+ 0.00 10 11 12 13 14 Time (min) Hydrograph Report 102 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 09 125 / 2019 Hyd. No. 58 8-7 Hydrograph type = Reach Peak discharge = 1.651 cfs Storm frequency = 2 yrs Time to peak = 0.12 hrs Time interval = 1 min Hyd. volume = 644 cuft Inflow hyd. No. = 56 - 8 Combined Section type = Circular Reach length = 40.5 ft Channel slope = 6.4 % Manning's n = 0.012 Bottom width = 1.0 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 16.923 Rating curve m = 1.250 Ave. velocity = 0.00 fus Routing coeff. = 1.3089 Modified Att-Kin routing method used. Q (cfs) 2.00 1.00 0.00 0.0 0.0 Hyd No. 58 8-7 Hyd. No. 58 -- 2 Year 0.1 0.1 — Hyd No. 56 0.1 0.2 0.2 0.2 Q (cfs) 2.00 1.00 wm+- 0.00 0.3 Time (hrs) Hydrograph Report 103 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc, v2020 Hyd. No. 58 8-7 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 56 - 8 Combined Section type Reach length = 40.5 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 16.923 Rating curve m Ave. velocity = 0.00 ft/s Routing coeff. Modified Aft -Kin routing method used Q (Cfs) 3.00 2.00 1.00 8-7 Hyd. No. 58 -- 10 Year Wednesday, 09/25/2019 = 2.242 cfs = 0.12 hrs = 822 cuft = Circular = 6.4 % = 1.0ft = 0.0 ft = 1.250 = 1.4384 Q (Cfs) 3.00 2.00 1.00 0.00 If I IrI IrI I I I I 10.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 Hyd No. 58 — Hyd No. 56 Time (hrs) Hydrograph Report 104 Hydraflow Hydrographs Extension for Autodesk® Civil 3DO2019 by Autodesk, Inc. v2020 Hyd. No. 59 7-EX2 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 58 - 8-7 Section type Reach length = 12.3 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 14.786 Rating curve m Ave. velocity = 0.00 fus Routing coeff. Modified Att-Kin routing method used. Q (cfs) 2.00 1.00 0.00 0.0 0.0 Hyd No. 59 7-EX2 Hyd. No. 59 -- 2 Year 0.1 0.1 Hyd No. 58 Wednesday, 09/25/2019 = 1.668 cfs = 0.13 hrs = 658 cuft = Circular = 4.9 % = 1.0 ft = 0.0 ft = 1.250 = 1.7298 0.1 0.2 0.2 0.2 0.3 Q (cfs) 2.00 1.00 1 0.00 0.3 Time (hrs) Hydrograph Report 105 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc, v2020 Hyd. No. 59 7-EX2 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 58 - 8-7 Section type Reach length = 12.3 ft Channel slope Manning's n = 0.012 Bottom width - Side slope = 0.0:1 Max. depth Rating curve x = 14.786 Rating curve m Ave. velocity = 0.00 ft/s Routing coeff. u Modified Att-Kin routing method used Q (cfs) 3.00 2.00 1.00 7-EX2 Hyd. No. 59 -- 10 Year Wednesday, 09 / 25 / 2019 = 2.256 cfs = 0.12 hrs = 840 cuft = Circular = 4.9 % = 1.0ft = 0.0 ft = 1.250 = 1.7938 Q (cfs) 3.00 2.00 1.00 0.00 " 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 Time (hrs) — Hyd No. 59 —Hyd No. 58 Hydrograph Report 106 n e Hydraflow Hydrographs Extension for Autodesk® Civil 3DO2019 by Autodesk, Inc. v2020 Hyd. No. 60 EX2-5 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 59 - 7-EX2 Section type Reach length = 61.4 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 8.076 Rating curve m Ave. velocity = 0.00 ft/s Routing coeff. Modified Att-Kin routing method used. Q (cfs) 2.00 1.00 EX2-5 Hyd. No. 60 -- 2 Year 0.00 0 0 0 0 0 0 0 0 0 0 0 i i 0 0 Hyd No. 60 — Hyd No. 59 Wednesday, 09 / 25 / 2019 = 0.904 cfs = 0.18 hrs = 849 cult = Circular = 0.9 % = 4.5 ft = 0.0 ft = 1.250 = 0.1204 Q (cfs) 2.00 1.00 0.00 1 1 1 Time (hrs) Hydrograph Report 107 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 09 / 25 / 2019 Hyd. No. 60 EX2-5 Hydrograph type = Reach Peak discharge = 1.321 cfs Storm frequency = 10 yrs Time to peak = 0.18 hrs Time interval = 1 min Hyd. volume = 1,028 cuft Inflow hyd. No. = 59 - 7-EX2 Section type = Circular Reach length = 61.4 ft Channel slope = 0.9 % Manning's n = 0.012 Bottom width = 4.5 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 8.076 Rating curve m = 1.250 Ave. velocity = 0.00 ft/s Routing coeff. = 0.1595 Modified Aft -Kin routing method used. Q (cfs) 3.00 2.00 t 1.00 EX2-5 Hyd. No. 60 -- 10 Year Q (cfs) 3.00 2.00 1.00 0.00 l 1 1 1 1 1 1 Y I 1 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 Time (hrs) — Hyd No. 60 —Hyd No. 59 Hydrograph Report 108 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 62 6A-6 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 14 - DA-6A Section type Reach length = 89.9 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 10.267 Rating curve m Ave. velocity = 0.00 ft/s Routing coeff. Modified Att-Kin routing method used 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.00 0.0 0.0 Hyd No. 62 0.1 0.1 - Hyd No. 14 Wednesday, 09/25/2019 = 0.814 cfs = 0.10 hrs = 322 cult = Circular = 2.2 % = 1.3 ft = 0.0 ft = 1.250 = 0.5063 0.1 0.2 0.2 0.2 0 Q (Cfs) 1.00 0.70 0.60 0.50 0.40 0.30 0.20 109 Hydrograph Report Hydraflow Hydrogrephs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 " Hyd. No. 62 6A-6 Hydrograph type = Reach Peak discharge = 1.124 cfs Storm frequency = 10 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 410 cuft Inflow hyd. No. = 14 - DA-6A Section type = Circular Reach length = 89.9 ft Channel slope = 2.2 % Manning's n = 0.012 Bottom width = 1.3 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 10.267 Rating curve m = 1.250 Ave. velocity = 1.05 fbs Routing coeff. = 0.6083 Modified Att-Kin routing method used. I 6A-6 Q (Cfs) Hyd. No. 62 -- 10 Year Q (Cfs) 2.00 2.00 1.00 1.00 i I l 0.00 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 — Hyd No. 62 — Hyd No. 14 Time (hrs) 110 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 ' Hyd. No. 63 6 Combined Hydrograph type = Combine Peak discharge = 1.953 cfs Storm frequency = 2 yrs Time to peak = 0.08 hrs ,Time interval = 1 min Hyd. volume = 720 cuft Inflow hyds. = 13, 62 Contrib. drain. area = 0.350 ac L a 6 Combined Q (cfs) Hyd. No. 63 — 2 Year Q (Gfs) 2.00 2.00 1.00 1.00 00, 0.00 0.00 0.0 0.0 0.0 0.1 0.1 0.1 0.1 0.1 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 Time (hrs) — Hyd No. 63 —Hyd No. 13 —Hyd No. 62 Hydrograph Report 111 Hydraflow Hydrographs Extension for Autodesk® Civil 3D02019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 63 6 Combined Hydrograph type = Combine Peak discharge = 2.583 cfs Storm frequency = 10 yrs Time to peak = 0.08 hrs Time interval = 1 min Hyd. volume = 923 cuft Inflow hyds. = 13, 62 Contrib. drain. area = 0.350 ac Q (cfs) 3.00 2.00 1.00 0.00 = 0.0 0.0 0.0 — Hyd No. 63 6 Combined Hyd. No. 63 -- 10 Year 0.1 0.1 0.1 — Hyd No. 13 0.1 0.1 0.1 Hyd No. 62 0.2 0.2 0.2 0.2 Q (cfs) 3.00 2.00 1.00 0.00 0.2 Time (hrs) Hydrograph Report 112 ' Hydraflow Hydrographs Extension for Autodesk® Civil 3138 2019 by Autodesk, Inc. v2020 Hyd. No. 65 6-5 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 63 - 6 Combined Section type Reach length = 35.4 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth - Rating curve x = 19.619 Rating curve m Ave. velocity = 1.59 ft/s Routing coeff. Modified Att-Kin routing method used. Q (Cfs) 2.00 1.00 0.00 ' 1 1' 0.0 0.0 0.0 0.1 — Hyd No. 65 6-5 Hyd. No. 65 -- 2 Year 0.1 0.1 0.1 Hyd No. 63 0.1 Wednesday, 02 / 20 / 2019 = 2.044 cfs = 0.10 hrs = 742 tuft = Circular = 8.0 % = 1.3 ft = 0.0 ft = 1.250 = 1.2553 Q (Cfs) 2.00 1.00 ' 0.00 0.1 0.2 0.2 0.2 0.2 0.2 0.2 0.3 Time (hrs) Hydrograph Report 113 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 02 ! 20 / 2019 Hyd. No. 65 6-5 Hydrograph type = Reach Peak discharge = 2.745 cfs Storm frequency = 10 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 950 cuft Inflow hyd. No. = 63 - 6 Combined Section type = Circular Reach length = 35.4 ft Channel slope = 8.0 % Manning's n = 0.012 Bottom width = 1.3 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 19.619 Rating curve m = 1.250 Ave. velocity = 2.11 ft/s Routing coeff. = 1.3807 Modified Att-Kin routing method used Q (Cfs) 3.00 2.00 1.00 0.00 ' ' 0.0 0.0 0.0 — Hyd No. 65 6-5 Hyd. No. 65 -- 10 Year 0.1 0.1 0.1 0.1 — Hyd No. 63 0.1 0.1 0.2 0.2 0.2 0.2 0.2 Q (cfs) 3.00 2,00 1.00 wnl►- 0.00 0.2 Time (hrs) Hydrograph Report 114 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk. Inc. v2020 r_ Hyd. No. 66 5A-5 Hydrograph type = Reach Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 12 - DA-5A Section type Reach length = 11.1 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 18.776 Rating curve m Ave. velocity = 0.00 ft/s Routing coeff. Wednesday, 09 125 12019 = 2.234 cfs = 0.10 hrs = 654 cuft = Circular = 7.3 % = 1.3 ft = 0.0 ft = 1.250 = 1.7052 I Modified Att-Kin routing method used. I 5A-5 Q (Cfs) Hyd. No. 66 -- 2 Year f Q (ofs) 3.00 3.00 2.00 2.00 JO 1.00 1.00 0.00 . 0.0 0.0 — Hyd No. 0.0 0.1 0.1 0.1 66 — Hyd No. 12 0.1 0.1 0.1 0.2 0.00 0.2 0,2 Time (hrs) Hydrograph Report 115 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 66 5A-5 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 12 - DA-5A Section type Reach length = 11.1 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 18.776 Rating curve m Ave. velocity = 2.21 ft/s Routing coeff. Modified Att-Kin routing method used Q (cfs) 3.00 2.00 1.00 0.00 K ' ' 0.0 0.0 0.0 — Hyd No. 66 5A-5 Hyd. No. 66 — 10 Year 0.1 0.1 — Hyd No. 12 Wednesday, 0212012019 = 2.867 cfs = 0.10 hrs = 843 cuft = Circular = 7.3 % = 1.3 ft = 0.0 ft = 1.250 = 1.7635 0.1 0.1 0.1 0.1 0.2 0.2 Q (cfs) 3.00 2.00 1.00 1 0.00 0.2 Time (hrs) Hydrograph Report 116 ' Hydraflow Hydrographs Extension for Autodesk® Civil 31382019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 67 5 Combined Hydrograph type = Combine Peak discharge = 4.750 cfs Storm frequency = 2 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 2,245 cuft Inflow hyds. = 60, 65, 66 Contrib. drain. area = 0.000 ac Q (cfs)' 5.00 4.00 3.00 2.00 1.00 5 Combined Hyd. No. 67 — 2 Year 0.00 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 — Hyd No. 67 — Hyd No. 60 — Hyd No. 65 0 1 1 — Hyd No. 66 Q (Cfs) 5.00 4.00 3.00 2.00 1.00 0.00 1 1 Time (hrs) Hydrograph Report 117 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02 / 20 / 2019 Hyd. No. 67 5 Combined Hydrograph type = Combine Peak discharge = 6.275 cfs Storm frequency = 10 yrs Time to peak = 0.10 hrs Time interval = 1 min Hyd. volume = 2,821 cuft Inflow hyds. = 60, 65, 66 Contrib. drain. area = 0.000 ac Q (cfs) 7.00 5.00 4.00 3.00 2.00 1.00 5 Combined Hyd. No. 67 - 10 Year Q (cfs) 7.00 M 5.00 4.00 3.00 2.00 1.00 0.00 ' 1 1 1 1 10.00 0.0 0.0 0.1 0.1 0.1 0.2 0.2 0.2 0.3 0.3 0.3 0.4 0.4 0.4 0.5 0.5 Time (hrs) Hyd No. 67 -Hyd No. 60 -Hyd No. 65 -Hyd No. 66 118 Hydrograph Report Hydrafiow Hydrographs Extension for Autodesk® Civil 3DS 2019 by Autodesk, Inc. v2020 Wednesday, 02 120 / 2019 Hyd. No. 69 5-E7 Hydrograph type = Reach Peak discharge = 3.006 cfs Storm frequency = 2 yrs Time to peak = 0.15 hrs Time interval = 1 min Hyd. volume = 2,632 cuft Inflow hyd. No. = 67 - 5 Combined Section type = Circular Reach length = 102.6 ft Channel slope = 0.9 % Manning's n = 0.012 Bottom width = 4.5 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 8.302 Rating curve m = 1.250 Ave. velocity = 0.30 ft/s Routing coeff. = 0.1969 Modified Att-Kin routing method used. Q (cfs) 5.00 4.00 3.00 PA41I am Q Ids) 5.00 4.00 3.00 1.00 0.00 1 1 1 1 1 1 1 1 1 1 I I I 1 1 1 -i 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 Time (hrs) — Hyd No. 69 —Hyd No. 67 Hydrograph Report 119 Hydraflow Hydrogmphs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Wednesday, 02120 12019 ' Hyd. No. 69 5-E7 Hydrograph type = Reach Peak discharge = 4.294 cfs ' Storm frequency = 10 yrs Time to peak = 0.15 hrs Time interval = 1 min Hyd. volume = 3,211 cuft Inflow hyd. No. = 67 - 5 Combined Section type = Circular Reach length = 102.6 ft Channel slope = 0.9 % ,+ Manning's n = 0.012 Bottom width = 4.5 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 8.302 Rating curve m = 1.250 Ave. velocity = 0.39 fUs Routing coeff. = 0.2521 Modified Att-Kin muting method used. r ,i Q (Cfs) r 7.00 6.00 5.00 4.00 3.00 2.00 1.00 5-E7 Hyd. No. 69 -- 10 Year Q (cfs) 7.00 we A11111 4.00 3.00 2.00 1.00 0.00 ff ' ' ' ' ' ' ' — 0.00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 — Hyd No. 69 — Hyd No. 67 Time (hrs) Hydrograph Report 120 - Hydraflow Hydrographs Extension for Autodesk® Civil 3DID2019 by Autodesk, Inc. v202D Hyd. No. 80 E7 Combined Hydrograph type = Combine Peak discharge ' Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 69, 78 Contrib. drain. area Q (cfs) 5.00 4.00 3.00 2.00 1.00 E7 Combined Hyd. No. 80 — 2 Year Wednesday, 02120 / 2019 = 4.312 cfs = 9 min = 3,213 cuft = 0.000 ac Q (cfs) 5.00 4.00 3.00 2.00 1.00 0.0o -► 1 I I I I I 1 - 1 i 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Time (min) — Hyd No. 80 —Hyd No. 69 —Hyd No. 78 Hydrograph Report 121 Hydraflow Hydrographs Extension for Autodesk® Civil ME) 2019 by Autodesk, Inc. v2020 Wednesday, 02120 12019 Hyd. No. 80 E7 Combined Hydrograph type = Combine Peak discharge = 6.055 cfs Storm frequency = 10 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 3,954 cult Inflow hyds. = 69, 78 Contrib. drain. area = 0.000 ac Q (Cfs) 7.00 4X6I17 4.00 3.00 2.00 1.00 0.00 W I I' 0 2 4 6 — Hyd No. 80 E7 Combined Hyd. No. 80 -- 10 Year Q (cfs) 7.00 We 5.00 4.00 3.00 2.00 MRoU] ' ' 0.00 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 Time (min) — Hyd No. 69 —Hyd No. 78 Hydrograph Report 122 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Wednesday, 0212012019 Hyd. No. 81 E7-1 Hydrograph type = Reach Peak discharge = 2.979 cfs Storm frequency = 2 yrs Time to peak = 12 min Time interval = 1 min Hyd. volume = 3,948 cuft Inflow hyd. No. = 80 - E7 Combined Section type = Circular Reach length = 143.8 ft Channel slope = 1.3 % Manning's n = 0.012 Bottom width = 4.5 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 9.702 Rating curve m = 1.250 Ave. velocity = 0.27 ft/s Routing coeff. = 0.1321 Modified Att-Kin routing method used Q (cfs) 5.00 4.00 3.00 2.00 1.00 E7-1 Hyd. No. 81 — 2 Year 0.00 0 10 20 30 40 50 — Hyd No. 81 — Hyd No. 80 Q (cfs) 5.00 1 3.00 2.00 1.00 WE*- 0.00 60 Time (min) Hydrograph Report 123 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 81 E7-1 Hydrograph type = Reach Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 80 - E7 Combined Section type Reach length = 143.8 ft Channel slope Manning's n = 0.012 Bottom width Side slope = 0.0:1 Max. depth Rating curve x = 9.702 Rating curve m Ave. velocity = 0.38 ft/s Routing coeff. Modified Att-Kin routing method used. Q (cfs) 7.00 . �Z 5.00 MIX 3.00 2.00 1.00 E7-1 Hyd. No. 81 — 10 Year Wednesday, 02 / 20 / 2019 = 4.421 cfs = 12 min = 4,647 cuft = Circular = 1.3 % = 4.5 ft = 0.0 ft = 1.250 = 0.1807 Q (cfs) 7.00 MM 5.00 4.00 3.00 2.00 1.00 0.00 — 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (min) — Hyd No. 81 —Hyd No. 80 Hydrograph Report 124 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 83 1 Combined Hydrograph type = Combine Peak discharge !, Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 18, 46, 81 Conthb. drain. area Q (cfs) 15.00 12.00 • 01 . 11 3.00 1 Combined Hyd. No. 83 -- 2 Year Thursday, 02 121 / 2019 = 14.64 cfs = 8 min = 8,289 cult = 0.870 ac Q (cfs) 15.00 12.00 WE 3.00 0.00 9— r ' ' ' ' ' „' 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (min) — Hyd No. 83 —Hyd No. 18 —Hyd No. 46 —Hyd No. 81 Hydrograph Report 125 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Thursday, 02 / 21 / 2019 Hyd. No. 83 1 Combined Hydrograph type = Combine Peak discharge = 21.92 cfs Storm frequency = 10 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 10,858 cuft Inflow hyds. = 18, 46, 81 Contrib. drain. area = 0.870 ac Q (cfs) 24.00 20.00 16.00 12.00 M 4.00 0.00 cam,— ' ' 0 2 4 6 — Hyd No, 83 1 Combined Hyd. No. 83 — 10 Year Q (cfs) 24.00 20.00 16.00 12.00 4.00 ' 0.00 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Time (min) — Hyd No. 18 —Hyd No. 46 —Hyd No. 81 126 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D@ 2019 by Autodesk, Inc. v2020 Thursday, 02 / 2112019 Hyd. No. 84 1-Arbor Hydrograph type = Reach Peak discharge = 21.27 cfs Storm frequency = 2 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 8,427 cuft - Inflow hyd. No. = 83 - 1 Combined Section type = Circular _- Reach length = 85.2 ft Channel slope = 1.3 % " Manning's n = 0.012 Bottom width = 0.0 ft Side slope = 0.0:1 Max. depth = 0.0 ft Rating curve x = 0.000 Rating curve m = 1.250 Ave. velocity = Infinity ft/s Routing coeff. = 2.0000 t I -Arbor .No. 84 -- 2 Year Q i 30C 15. pit I .00 r�■■■■■■■ i ��i �►�a,... _Minn■■■■■■■■ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (min) — Hyd No. 84 —Hyd No. 83 3) Hydrograph Report 127 1/2019 Q (cfs) 24.00 ri I� 16.00 12.00 WE I I. 0.00 1 I 1 1 1 1 1 1 1 1 1 1 • I r I y Iy Iy-r%rrcM 1� 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Time (min) — Hyd No. 84 —Hyd No. 83 Hydrograph Report 128 Hydraflow Hydrographs Extension for Autodesk® Civil 3DO 2019 by Autodesk, Inc. v2020 Hyd. No. 86 Overland Flow to Biofilter Hydrograph type = Rational Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 1.840 ac Runoff. coeff. Intensity = 3.511 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 3.00 2.00 1.00 0.00 Y 0 2 4 — Hyd No. 86 Overland Flow to Biofilter Hyd. No. 86 — 2 Year 6 8 10 12 Thursday, 02/21/2019 = 2.132 cfs = 15 min = 1,919 cult = 0.33 = 15.00 min = 1/1 Q (cfs) 3.00 EC 1.00 I I 1 I 1 I I 1y 0.00 14 16 18 20 22 24 26 28 30 Time (min) Hydrograph Report 129 Hydraflow Hydrographs EMension for Autodesk® Civil 308 2019 by Autodesk, Inc. v2020 Hyd. No. 86 Overland Flow to Biofilter Hydrograph type = Rational Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 1.840 ac Runoff coeff. r Intensity = 4.558 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (cfs) 3.00 2.00 1.00 0.00 r I ' 0 2 4 — Hyd No. 86 Overland Flow to Biofilter Hyd. No. 86 -- 10 Year 6 8 10 12 14 Thursday, 02 121 / 2019 = 2.768 cfs = 15 min = 2,491 cuft = 0.33 = 15.00 min = 1/1 Q (cfs) 3.00 2.00 1.00 0.00 16 18 20 22 24 26 28 30 Time (min) Hydrograph Report 130 Hydrafiow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 r Hyd. No. 86 Overland Flow to Biofilter Hydrograph type = Rational Peak discharge Storm frequency = 100 yrs Time to peak Time interval = 1 min Hyd. volume Drainage area = 1.840 ac Runoff. coeff. Intensity = 6.017 in/hr Tc by User IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact Q (Cfs) 4.00 3.00 2.00 1.00 0.00 — 0 2 4 Hyd No. 86 6 8 Overland Flow to Biofilter Hyd. No. 86 -- 100 Year Thursday, 02 / 21 / 2019 = 3.653 cfs = 15 min = 3,288 cuft = 0.33 = 15.00 min = 1/1 Q (cfs) 4.00 3.00 2.00 1.00 II I I I I I I 1 1 V 0.00 10 12 14 16 18 20 22 24 26 28 30 Time (min) Hydrograph Report 131 Hydrallow Hydrographs Extension for Autodesk® Civil 3136 2019 by Autodesk, Inc. v2020 Thursday, 02 / 2112019 Hyd. No. 87 Combined inflow to BF Hydrograph type = Combine Peak discharge = 6.519 cfs Storm frequency = 2 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 11,948 cult Inflow hyds. = 47, 86 Contrib. drain. area = 1.840 ac Q (cfs) 7.00 . M 611N11 4.00 3.00 2.00 1.00 0.00 0 2 4 Hyd No. 87 M Combined inflow to BF Hyd. No. 87 — 2 Year Q (cfs) 7.00 . 11 5.00 4.00 3.00 2.00 1.00 L I i i WMEM"t- 0.00 8 10 12 14 16 18 20 22 24 26 28 30 Time (min) — Hyd No. 47 —Hyd No. 86 Hydrograph Report 132 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Thursday, 02 / 21 / 2019 Hyd. No. 87 Combined inflow to BF Hydrograph type = Combine Peak discharge = 7.799 cfs Storm frequency = 10 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 12,818 cuft Inflow hyds. = 47, 86 Contrib. drain. area = 1.840 ac Q (cfs) 8.00 4.00 2.00 0.00 '� ' 0 2 4 Hyd No. 87 Combined inflow to BF Hyd. No. 87 -- 10 Year 6 8 10 12 14 — Hyd No. 47 Q (cfs) 8.00 4.00 2.00 0.00 16 18 20 22 24 26 28 30 Hyd No. 86 Time (min) Hydrograph Report 133 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Thursday, 02 / 21 / 2019 Hyd. No. 87 Combined inflow to BF Hydrograph type = Combine Peak discharge = 10.18 cfs Storm frequency = 100 yrs Time to peak = 8 min Time interval = 1 min Hyd. volume = 14,033 cuft Inflow hyds. = 47, 86 Contrib. drain. area = 1.840 ac Q (cfs) 12.00 10.00 am 4.00 2.00 0.00 0 2 4 — Hyd No. 87 Combined inflow to BF Hyd. No. 87 -- 100 Year 6 8 10 12 14 — Hyd No. 47 Q (Cfs) 12.00 10.00 : e, 4.00 2.00 0.00 16 18 20 22 24 26 28 30 Time (min) — Hyd No. 86 Hydrograph Report 134 nyoranow nyarograpns txrension Tor RUTooesxw Uwn sUW Zu-ie ay Humaeer<, mu. v<u<u . Hyd. No. 89 Biofilter - Hydrograph type = Reservoir Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 87 - Combined inflow to BF Max. Elevation Reservoir name = Biofilter Max. Storage J j " Storage Indication method used. :I Biofilter Q (cfs) Hyd. No. 89 -- 2 Year 7.00 6.00 f 5.00 4.00 3.00 l i- 2.00 1.00 0.00 �='' 0 2 4 6 — Hyd No. 89 Thursday, 02 121 / 2019 = 6.470 cfs = 9 min = 11,355 tuft = 478.79 ft = 928 cuft M 5.00 4.00 3.00 2.00 1.00 1 i I I I I I I I fir 0.00 8 10 12 14 16 18 20 22 24 26 28 30 32 34 — Hyd No. 87 =7 Total storage used = 928 tuft Time (min) 135 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D@ 2019 by Autodesk, Inc. v2020 Thursday, 02 / 21 / 2019 Hyd. No. 89 Biofilter Hydrograph type = Reservoir Peak discharge = 7.643 cfs Storm frequency = 10 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 12,225 cuft Inflow hyd. No. = 87 - Combined inflow to BF Max. Elevation = 478.82 ft Reservoir name = Biofilter Max. Storage = 968 cuft Storage Indication method used. Q (cfs) 8.00 6.00 4.00 2.00 Biofilter Hyd. No. 89 -- 10 Year Q (cfs) 8.00 - II 2.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (min) — Hyd No. 89 — Hyd No. 87 ____. Total storage used = 968 cuft 136 Hydrograph Report Hydrailow Hydrographs Extension for Autodesk® Civil 3D0 2019 by Autodesk, Inc. v2020 Thursday, 0212112019 Hyd. No. 89 Biofilter • Hydrograph type = Reservoir Peak discharge = 9.436 cfs Storm frequency = 100 yrs Time to peak = 9 min Time interval = 1 min Hyd. volume = 13,439 cult Inflow hyd. No. = 87 - Combined inflow to BF Max. Elevation = 478.89 ft Reservoir name i = Biofilter Max. Storage = 1,025 cuft Storage Indication method used. Biofilter Q (cfs) Hyd. No. 89 -- 100 Year Q (cfs) 12.00 10.00 8.00 6.00 4.00 2.00 000 12.00 10.00 8.00 6.00 4.00 2.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 Time (min) — Hyd No. 89 —Hyd No. 87 _ - _ __ Total storage used = 1,025 cult Pond Report 137 r - nyurauow nyvrograpns G enslon for wutooesKw uvn aww cv I a uy nuwuebR, Inc. vcucu "j Pond No. 3 - Biofilter Pond Data i°( Contours -User -defined contour areas. Conic method used for volume calculation. Begining Elevation = 478.00 It Stage / Storage Table Stage (ft) Elevation (ft) Contour area (sqft) [nor. Storage (tuft) Total storage (cult) 0.00 478.00 986 0 0 1.00 479.00 1,384 1,179 1,179 2.00 480.00 1.839 1,606 2.785 Culvert / Orifice Structures [A] [B] [C] [PrfRsr] Rise (in) = 18.00 0.00 0.00 0.00 Span (in) = 18.00 0.00 0.00 0.00 No. Barrels = 1 0 0 0 Invert El. (ft) = 474.55 0.00 0.00 0.00 Length (ft) = 35.15 0.00 0.00 0.00 Slope (%) = 2.50 0.00 0.00 n/a N-Value = .012 .013 .013 n1a Orifice Coeff. = 0.60 0.60 0.60 0.60 Multistage = n/a No No No Stage (ft) 2.00 1.80 1.60 1.40 1.20 1.00 0.80 0.60 0.40 0.20 0 00 Thursday, 02/21/2019 Weir Structures [A] [B] [C] [D] Crest Len (ft) = 12.56 Inactive 0.00 0.00 Crest El. (ft) = 478.50 0.00 0.00 0.00 Weir Coeff. = 3.33 3.33 3.33 3.33 Weir Type = 1 Ciplti - - Multi -Stage = Yes No No No Exfll.(in/hr) = 0.000(by Wet area) TW Elev. (ft) = 0.00 Note: CulverVOnfoe outflows are analyzed under inlet(ic) and nutlet(oc) control. Weir risers checked for onfice conditions(ic) and submergence(s). Stage I Discharge Elev (it) 480.00 479.80 479.60 479.40 479.20 479.00 478.80 478.60 478.40 478.20 47800 0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00 16.00 18.00 20.00 Total 0 Discharge (cfs) Hydrograph Report 138 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 91 Arbor + Biofilter Hydrograph type = Combine Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 84, 89 Contrib. drain. area Q (Cfs) 28.00 24.00 20.00 16.00 12.00 o 4.00 Arbor + Biofilter Hyd. No. 91 -- 2 Year Thursday, 02 / 2112019 = 27.74 cfs = 9 min = 19,782 cuft = 0.000 ac Q (cfs) 28.00 24.00 20.00 16.00 12.00 MI 4.00 0.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 Time (min) — Hyd No. 91 —Hyd No. 84 —Hyd No. 89 Hydrograph Report 139 Hydraflow Hydrographs Extension for Autodesk® Civil 3D®2019 by Autodesk, Inc. v2020 Hyd. No. 91 Arbor + Biofilter Hydrograph type = Combine Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 84, 89 Contrib. drain. area Q (cfs; 50.00 40.00 30.00 20.00 10.00 Thursday, 02/21/2019 = 43.18 cfs = 9 min = 23,234 tuft = 0.000 ac Q (cfs) 50.00 40.00 30.00 20.00 10.00 0.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Time (min) — Hyd No. 91 —Hyd No. 84 —Hyd No. 89 Hydrograph Report 140 Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 96 i, New Plan no Biofilter Hydrograph type = Combine Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 46, 84, 86 Contrib. drain. area Q (cfs) 35.00 30.00 25.00 20.00 15.00 10.00 5.00 New Plan no Biofilter Hyd. No. 96 — 2 Year Thursday, 02/21/2019 = 33.25 cfs = 9 min = 14,033 cuft = 1.840 ac Q (cfs) 35.00 30.00 25.00 20.00 15.00 10.00 5.00 0.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 Time (min) — Hyd No. 96 —Hyd No. 46 —Hyd No. 84 —Hyd No. 86 Hydrograph Report ME Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 96 New Plan no Biofilter Hydrograph type = Combine Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyds. = 46, 84, 86 Contrib. drain. area Q (cfs) 60.00 50.00 40.00 30.00 20.00 10.00 0.00 0 2 4 6 — Hyd No. 96 New Plan no Biofilter Hyd. No. 96 -- 10 Year Thursday, 02121 12019 = 52.00 cfs = 9 min = 18,866 cuft = 1.840 ac Q (cfs) 60.00 50.00 40.00 30.00 20.00 10.00 0.00 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 Time (min) — Hyd No. 46 —Hyd No. 84 —Hyd No. 86 JN�Y OF /�LDCny�n o t •1 �X el Department of Planning SUBDIVISION PLAT APPLICATION X Preliminary Plat Final Plat Date Submitted 1/4/8 8 _ First Hearing Month Desired Number of Copies Submitted (First Submittal, 12 Copies Requiredl 14 TITLE OF PROTECT FOREST LAKES (Phase I - Section II) Number of Lots 99 70' x 140' (55) Average Size SS' x 1nq'_(44) Open Area: 7.94 AC Residue TnYprnal Rnar9s• 5.01 AC Acreage of Site 41.42 Type Use Single Family Residential Other LOyA•ri ON : Off east side of Rt. 29 N. , North c5f Hollymead- Lake and extending --1' northward Magisterial District Rivanna Existing zoning R-4 Tax Map Part of Parcels 46-29D, Parcel(s) 46-29, 46-29E OWNER/DEVELOPER porpat T,akeS ASSOCiateS Address 500 Faulconer Drive, Charlottesville VA Tel.979-9500 22901 SURVEYOR/ARCHITECT/LAND PLANNER Clower Associates, Inc. Address P. 0 Box 29349 Richmond VA 23229 Tel. 741-1754 CONTACT PERSON Gary L. Clower or Robert H. Fitz, Jr. Address P. 0. Box 29349, Richmond VA 23229 Tel. 741-7154 • Subdivision Plat Fee Paid Due • The Subdivision Plat application process tn�ludes providing the Planning Commission with all the information required in the Land Subdivision and Development Ordinance, Chapter 18 of the County Code. • The.foregoing information is complete and correct to the best of my knowledge- I have read and understand the provisions of the Albemarle County Land Subdivision and Dcvclnpmcnt Ordinance applicable to this application. ? , Date January A 19e8 . (rool.cr, Uonl,.lc"Iurchenor. Agrnt) J Location of existing and proposed ingress to and egress from the site, showing the distance to the centerline of the nearest existing street intersection Location and dimensions including height where applicable of all existing and proposed improvements including: buildings (maximum footprint) and other structures, walkways, fences, walls, rash container'outdoor lighting, landscaped areas and open space�€c°rcTational area and facilities, parking lots and other paved areas, loading and service areas together with proposed paving material types for all walks, parking lots and driveways, and signs Area dedicated or reserved for public use Landscape plan (Section 32.7.9) jJJA Traffic generation figures if required Q�pp`d r' Boundary dimensions r PROJECT DESCRIPTION Proposed uses and maximum acreage occupied by each use VMaximum number of dwelling units by type v Gross residential density _ pppp��-� �rr���_� ,,JJ����� �l�'l� I Square footage of recreation area (94-C� biv MP �I U Percent and acreage of open space r' —�Vla ximum square footage for commercial and industrial uses "_—Maximum number of employees Maximum floor area ratio and lot coverage if industrial _ / Vl/ Maximum height of all structures t tl Schedule of parking including maximum amount required and j' amount provided Maximum amount of impervious cover on the site If landscape plan is required, maximum amount of paved r parking and vehicular circulation areas EXISTING CONDITIONS/PROPOSED IMPROVEMENTS 17 Proposed phase lines and timing of development V Existing topography (5 foot contours up to 20% slope, 10 foot contours over 20€ slope) for entire site and a minimum of 200 feet outside the site Proposed grading (maximum 5 foot contours) supplemented whdre necessary by spot elevations , — Areas noted with slope of 25% or greater Cif Existing landscape features (32.7.9.4c) Name and location of all watercourses and other bodies of water adjacent to or on the site 400000 Indicate if the site is located within a reservoir watershed 9WLocation of septic setback lines from watercourses including intermittent streams and other bodies of water 100 year flood plain limits as shorn on official flood insurance maps for Albemarle County ?_ Existing and proposed streets, access easements and travelways, street names, state route rs, night of way �� lines and widths, centerline radi' pavement w Z,41 eld P _V Location and size of: existing water and sanitary sewer facilities and casements, storm sewer facilities, drainage channels and drainage easements '/ Proposed conceptual layout for water and sanitary sewer facilities and storm drainage facilities, including storm detention ponds or structures, indicating direction of flow in all pipes and water courses with arrows J Location of other existing and proposed utilities and utility easements , , , PRELIMINARY PLAN CHECKLIST FILING REQUIREMENTS _ Minimum accuracy standards: 7bley,�wv�o Boundary, setback, zoning lines - 1 foot:1,000 feet Existing contours - 1/2 contour interval Proposed contours - 5 feet horizontally and vertically Existing structures and features - 5 feet Proposed improvements - 5 feet Fourteen (14) clearly legible blue or back line copies for initial submittal. _ Seven (7) full-sized revised copies and one (1) reduced copy no larger than 11" x 17" at revision deadline _ Written waiver request(s) clearly stating the spocific item being requested for waiver and justification therefor Plan scale of 1 inch equals 20 feet or larger. —' No sheet to be larger than 42 inches by 36 inches. If more than 1 sheet, match lines must be indicated. TITLE BLOCK AND IDENTIFICATION Name of development ,Name of owner/developer Name of individual who prepared the plan ✓ max Map and Parcel number ✓_% zoning with description of variances, zoning proffers and /. bonus factors applicable to the site ✓/. Magisterial district J County and state 7 North Point Scale rnyUV� _ OnM-Rd"atwn reference for elevation ✓ source of the topography ✓ Source of th- survey 7 Sheet number and total number of sheets V Date of drawing Date and description of latest revision '7C Owner zonin tax map rce er, departing lot lines an t�resent use of adjacent parcels Minimum setback lines, yard and building separation requirements Vicinity map at scale of 1 inch equals 2,000 feet ve l:O1N0ULLll.Y v1 aiv y.a.y Luc au, auu .. dwelling units per acre) residentia This property is within the nated for low density (1-4 use. School Impact: Project enrollment from this Section I subdivision is 78 students, who will attend Hollymead, Jack Jouett and Albemarle High Schools. The Education Department commented that Hollymead School has a new roof and expanded media center, and Jouett and Albemarle have no additional classroom space. Environmental Conditions: The topography ranges from relatively level to moderately steep. There are small areas of critical slope and portions of the existing Hollymead Lake floodplain on some proposed lots. Two lakes are proposed on the eastern side of Powell Creek Drive adjacent to Section 1A, and one lake is proposed on the western side between the proposed recreation area and a future townhouse area. Soils in this area consist of Glenelg loam and Elioak loam. These are deep and well drained soils. There may also be some very shallow Hazel loam on some of the steep slopes. These soils are also very erosive. This project is located outside the local watersupply watershed management areas. Measures should be undertaken during development to provide for water quality protection to the receiving streams. Utilities; Fire Protection: An eight inch water line is located within the right-of-way of Powell Creek Road. Fireflow from the nearest public hydrant within Hollymead is 1040 gallons per minute at 20 pounds per square inch, and from the hydrant at Route 29 is 1960 gallons per minute at 20 psi. An 18 inch sewer line is located 400 feet distant. The Service Authority is presently reviewing preliminary water and sewer plans. The proposed routing of the sewer line is consistent with Albemarle County Service Authority plans. The Service Authority is in the process of determining the sizing of the sewer line to accommodate other development in the area. The Fire Officer recommends hydrants. In the recreation area and future multi -family area, handicapped provisions are required. Stormwater Detention: Prior to signing (final approval) of the plat, a master drainage study shall be approved by the County Engineering Department. This study will have to be refined and updated to reflect current development with each phase of development. The lakes (existing and proposed) will provide stormwater detention. Transportation: (See attached Virginia Department of Transportation comments.) A traffic study is presently under review by the Virginia Department of Transportation (See "Staff Comment"). 9e r]� / C� / zl IDI / J -., I z2 ��• jV ; mL `IOA To / I Jr 2 N • . IDL �. �\• 1 / Js \ g � �! EO I' I InCJfn IT � ♦4�� / of b +4i s'y �.. / °Q•`�. �_ � u � j20G.N°ice%%- qb + t0. Ri NB 1 ! taf . ' t ♦ 20 ry„ Z94 139C .1) b tIJ N FDREsT4 4KE3 TxrN/-laUa� •�JEVEc.bPMJFNT.4 t.. : - �: ' S5 T. .. 1yi )O 11457 11 tE\ p IN f•1� / A] 2TA _3 31 EeA'\ P99 \ , u I • 6 / 29E � _ 19D •-1 ia. SIA O 35 Y 33F 1 • ba ,6Ten ..n -.. n-rftf 1 / Je6 \ d\ 31 no v rot 4 an •\ M / _ Ise \ tT •1 (jam y �K 38 ,Lh_ // 0 n , 4e ! P1. 78a 04 ez \. � IN / / •�?Ij' Y r�g66 . /� -I,)y- \ \. 444 57 \ 19 5TA • _ ILI V T 1 AT. leA � Pa �• N 4 24 % J 1 9ar93JnA ° h b • Vt / Aa9 \\ _ �.4UUM{++ 99 1. 95+ 99 /C r °•r�y n '. fie nA �w II. INTERNAL ROADS All proposed lots are to be served by internal roads as opposed to having direct access to either Meadowcreek or Forest Lakes Parkways. The plat has been designed to provide internal road intersections with Meadowcreek Parkway and Forest Lakes Parkway which provide the required crossover spacing. The Virginia Department of Transportation recommends an urban section for the internal roads, and the applicant has agreed. Joint driveways may be required for some cul-de-sac lots, where minimum entrance spacing cannot be met. This subdivision plat will meet the requirements of the Zoning ordinance and staff recommends approval subject to the following: RECOMMENDED CONDITIONS OF APPROVAL 1. The final plat shall be reviewed by the Planning Commission. The final plat will not be reviewed until the Virginia Department of Transportation has approved the traffic generation study. 2. The final plat will not be signed until the following conditions have been met: a. County Engineering approval of road and drainage plans and calculations; b. County Engineering approval of stormwater detention plans and calculations, to include installation and design of an emergency spillway on the existing dam; C. Virginia Department of Transportation approval of road and drainage plans and calculations, and approval of detention facilities which abut future state roads; d. Virginia Department of Transportation approval of Route 29 improvements and issuance of a commercial entrance permit in accordance with letter of October 8, 1987; e. Issuance of an erosion control permit; f. Issuance of an Operations and Maintenance Permit on the existing dam, from the State Water Control Board; g. County.Engineering approval of a comprehensive master drainage plan. Drainage plan is to be revised and kept updated with each phase of development; h. Albemarle County Service Authority approval of final water and sewer plans onsite and offsite; i. Fire Officer approval; 4 re Parkway/Powell Creek Drive to be closed at the northern end of the Phase I Forest Lakes development, at the point of intersection with Loop Road A. In addition, Forest Lakes Parkway is proposed to run east -west from Route 29 to Meadowcreek Parkway. (See discussion of Route 29) Consideration was given to permitting Powell Creek Drive to remain open out to Proffit Road, or to extending it as far as the connecting road to Jefferson Village. The existing Maple Grove Church building obstructs full sight distance to the east on Route 649. In addition, no development in the Phase I proposal would need this extension for direct access. A future connection to Jefferson Village, particularly for the purpose of school bus travel, will be further addressed with the Education Department and the traffic study. Although the Virginia Department of Transportation has not yet given approval to the applicant's traffic study, it appears that the alignment and right-of-way width are not subject to change. At issue is the number of lanes and corresponding design category for these roads. Agreements similar to those developed for Mill Creek PUD will be necessary for the Virginia Department of Transportation to accept these roads not built to their ultimate. B. Route 29 Access points and crossovers on Route 29 are delineated by the proffer with ZMA-85-20. The proposed Forest Lakes Parkway is to intersect Route 29 at Access Point two (AP2) at the New Crossover one. This New Crossover one requires the closing of the existing crossover (EC1) to the south. This closing will be completed by the Virginia Department of Transportation and is necessitated due to spacing requirements and the inadequate sight distance at this location. In the approval of the Central Fidelity Bank Plan, the Commission requested.that the Virginia Department of Transportation close the northern crossover. A full length left turn and taper lane will be constructed at the new crossover. Also in accordance with ZMA-85-20, a third lane on Route 29 will be constructed from the southern property line to this new connection. The traffic study will determine if a traffic signal will be necessary. 3 The recreation area is proposed to solely serve this development. The facilities include a swim and tennis club, several lakes, multi -purpose fields, basketball courts, and a network of jogging/biking trails. Planning staff recommends administrative approval of the recreation plans, as is typically done. The plat shows an area for three (3) future lots on which there is substantial floodplain and critical slopes. Approval for these lots is not sought at this time. It is noted "Future lots to be developed per County requirements." �i The plat proposes two (2) lakes, part of which will be under a 120 foot Virginia Power easement. The local office has recommended approval, and they are awaiting approval from the home office in Richmond. This is a condition to be met prior to signing the final plat. The existing Hollymead Lake and three (3) proposed lakes will provide stormwater detention. The Engineering Department has required submittal of a master drainage plan, to be updated as development occurs. In regards to existing Hollymead Lake, the following will be provided: a. Issuance of an Operations and Maintenance Permit on the existing dam from the State Water Control Board; b. Whether or not required by State Water Control Board, an emergency spillway will have to be constructed. The applicants intends to take measures to lower the existing floodplain, which will effectively diminish damage from flooding; C. A restriction to the minimum finished floor elevation to minimize loss from flooding. A discussion of roads external (Route 29, Route 649 and Meadowcreek Parkway) and internal to the development, is as follows: I. EXTERNAL i A. Meadowcreek Parkway The CATS study and Comprehensive Plan show the Meadowcreek Parkway extension to Proffit Road to generally align with the existing Powell Creek Drive. As the Commission is aware, this portion of Meadowcreek Parkway is not yet designed or formally committed. The present end of state maintenance for Powell Creek Drive is at the northern intersection of Tinker's Cove Road, just south of the dam for Hollymead Lake. The road presently continues northward to an intersection with Proffit Road. Partly as a result of the lack of approved road plans for this segment and partly due to the lack of the applicable dam permit, this segment has never been accepted into the state system. 2 STAFF PERSON STAFF REPORT AMELIA M. PATTERSON NOVEMBER 10, 1987 FOREST LAKES PHASE I. SECTION 1 PRELIMINARY PLAT Proposal: This plat (Section 1) proposes the creation of 164 single family lots from 109 acres, with the average lot size ranging from 0.26 acre (Section 1D) to 0.55 acre (Section 1A) for a gross density of 1.5 dwelling units per acre. All lots are to be served by proposed internal public roads. The plat proposes 7.9 acres of common open space and 11.7 acres of active recreation area, including swim and tennis facilities. Location: Off the east side of Route 29 North, adjacent to the north of the Hollymead Lake and extending northward. Proposed Section lA (8 acres) is on the east side of Powell Creek Drive and Sections 1B-D (67.5 acres) and the recreation area are on the west side. Tax Map 46, Parcels 29, 29D and 29E. Zoned R-4, Residential with proffer of 1.7 dwelling units per acre. Rivanna Magisterial District. STAFF COMMENT: The preliminary plat is presented as the Phase I Master Plan. In addition to the proposed single family lots, the plan shows area for townhouses and villas. The Phase I summary is as follows: I. SINGLE FAMILY "A" 8.09 ACRES/10 LOTS/0.55 ACRE AVERAGE SINGLE FAMILY "B" 17.78 ACRES/37 LOTS/0.33 ACRE AVERAGE SINGLE FAMILY "C" 17.23 ACRES/41 LOTS/0.29 ACRE AVERAGE SINGLE FAMILY "D" 32.47 ACRES/76 LOTS/0.26 ACRE AVERAGE II. VILLA "A" 9.10 ACRES/50 LOTS VILLA "B" 9.88 ACRES/40 LOTS III. TOWNHOUSES 4.50 ACRES/40 LOTS TOTAL 294 LOTS/DWELLING UNITS ON 276 ACRES = 1.07 DWELLING UNIT PER ACRE The proposed density (1.07 dwelling units per acre) is in compliance with the proffer (1.70 dwelling units per acre) of ZMA-83-19 Hollymead Land Trust and Albemarle Bank and Trust Company. Prior to completion of the final plat, there may be minor shifts in density. The villa and townhouse areas (Phas 1 COUNTY OF ALBEMARLE r Department of Zoning 401 McIntire Road Charlottesville, Virginia 22901-4596 ' (804) 296-5875 MEMORANDUM TO: Amelia Patterson Planner FROM: Kathy J. Brittain Administrative Assistant RE: Forest Lakes Phase I, Section II Preliminary Plat Forest Lakes Swim and Recreation Area Preliminary Site Plan Forest Lakes Townhouse Development Phase I "A" DATE: January 12, 1988 Please be advised that Charlie Burgess and I have reviewed the above referenced plan, and have the following comments: If the recreational facilities are not just for Forest Lake residents, a special use permit will be required. Also, please contact this department at your earliest convenience regarding density requirements. Your cooperation in this matter is appreciated. kib JAN is 1988 PLANNING DIVISION. 0 COMMONWEALTH OF VIRGINIA DEPARTMENT OF TRANSPORTATION Mrs. Amelia M. Patterson Site Plan Review Meeting Items 1 - 3 2. Forest Lakes Swim and Recreation Area Page 2 January 21, 1988 Route 2 North - A 100' long 12' wide right turn lane with a 100' long taper lane is required on Timber Wood Boulevard for the entrance to this site. The Department recommends a left turn lane on Timber Wood Boulevard for this site. The Department recommends two outbound lanes and one inbound lane for the entrance to this site. The commercial entrance should have 25' radii, if on an urban section and 35' radii, if on a rural section. The minimum sight distance requirments are 350' in each direction, if Timber Wood Boulevard is a two lane roadway and 400' of sight distance if it is a four lane highway. A sight easement may be necessary to the southeast of the entrance across the frontage of this site depending on the pavement and right of way width on Timber Wood Boulevard. 3. Forest Lake Route 2 North - a with CG-6 is adequate for this entrance. -,Me Department recommends that the first two parking entrances on site be eliminated so that vehicles do not back out into the entrance. The Department recommends that there be one lane inbound. (16' wide) and two lanes outbound (24' wide) for this entrance. The Department recommends that there be a 25' continuous radius on the eastern side of the entrance and this would necessitate redesigning the internal travelway. Any entrance aligning across from a future crossover on Timber Wood Parkway is required to a minimum of 475' of sight distance in all directions. The Department recommends that the entrance to this site align across from Cross Timbers Road so that there will not be a crossover at the minimum of 600' separation on Timber Wood Parkway at every location. Yours truly, D. S. Roosevelt Resident Engineer By: J. A. Echols Ass't. Resident Engineer JAE/dlc cc: Mr. J. F. Coates MEMO TO: John T.P.Horne January 22, 1988 Page Three FOREST LAKES - Swim & Tennis Recreation Area - Site Plan P�G)i.vr i /I d y 1) County EngineeringAapproval of road and drainage plans and calculations: a) Forest Lakes Parkway (Timberwood Boulevard) Nt .`i _ r - _ .. -i4C'Z�SYJ 111 V1L � "�� Eer-ciazze �r�--iettas--e�9s`c�'o--� � Q"� ! 4) Issuance of an Erosion Control Permit. I 5) County Engineering approval of site plan. FOREST LAKES - TOWNHOUSES "A" - Site Plan 1) County Engineering approval of road and drainage plans and calculations: a) Forest Lakes Parkway (Timberwood Boulevard) b) Meadowcreek Parkway (Timberwood Parkway) 2) County Engineering approval of stormwater detention plans and calculations to include installation and design of an emergency spillway on the existing dam. 3) Virginia Department of Transportation approval of road and L. drainage plans and calculations, and approval of detention facilities which abut future State roads. 4) Virginia Department of Transportation approval of Route 29 improvements and issuance of a commercial entrance permit in accordance with letter of October B, 1987. 5) Issuance of an Erosion Control Permit. 6) issuance of an Operations and Maintenance Permit on the existing dam. Forest Lakes Swim and Recreation Area Preliminary Site Plan (1) Must indicate type of curb cut in sidewalk at handicapped parking areas. (2) Fire flow requirements will be based on ISO stipulations and as approved by this office. Type of construction and square footage of buildings will need to be provided for evaluation as it pertains to minimum fire flows. Phase I "A" Fire flow requirements will be based on ISO stipulations and as approved by this office. Type of construction and square footage of buildings will need to be provided for evaluation as it pertains to minimum fire flows. RWJ/kgm ALBEMARLE - CHARLOTTESVILLE OFFICE OF WATERSHED MANAGEMENT 401 MCINTIRE ROAD I CHARLOTTESVILLE, VIRGINIA 22901-4596 WILLIAM K. NORRIS'ti( •...1 t .•' -<"( LEPHONE WATERSHED MANAGEMENT OFFICIAL 77 "F-1 - µ I�}`1 "d,(+. �'�._ (604 )11296-5641 1(yyY* � y MEMORANDUM ,�`! t_; i:;+, TO: Amelia M. Patterson, Planner FROM: William K. Norris, Watershed Management Official WK� DATE: January 19, 1988 SUBJECT: Site Plan Review Meeting January 21, 1988 Watershed Management Comments items Reviewed: Forest Lakes Phase I, Section II Preliminary Plat Forest Lakes Swim and Recreation Area Preliminary Site Plan Forest Lakes Townhouse Development Phase I "AI' Preliminary Site Plan - by: Clower Associates, Inc., January 4, 1988 Location: o The properties are located off of Route 29 North, at its intersection with Route 649 in Hollymead o Tax Map 46, Parcels 29, 29D and 29E Watershed Boundaries: o South Fork Riyanna-River Watershed o South Fork kivanna River Subwatershed o Powell Creek Basin o Hollymead/Forest Lake Subbasin Comment: o These projects are located outside of the local watersupply watershed. WKN/mlm wsm81-23 ALBEMARLE COUNTY SERVICE AUTHORITY MEMO To: Amelia Patterson, Planner FROM: W. L. Rossie, Chief Engineer DATE: January 20, 1988 RE: Site Plan Technical Review for: Forest Lakes Townhouse Development Phase I "A" The below checked items apply to this site. (TM 46, Parcel 29E) X_ 1. This site plan is12(2fX within the Authority's jurisdictional area for. X_ A. Water and sewer B. Water only _ C. Water only to existing structure _ _ D. Limited service as show (ffield verify) �i�tant. X_ 2. An 8 inch water line is located approximately X 3. Fire flow from nearest public hydrant, located distant from this site plan, is 1040 gpn at 20 psi residual. X_ 4. An 18 inch sewer Iine is located 48501+ distant. (offsite to intercept, 5. An Industrial Waste Ordinance survey form must be completed. X 6. No improvements or obstructions shall be placed within existing or future easements. _ 7, and plans are currently under review. _ 8. and plans have been received and approved. 9. No plans are required. X 10. Final water and sewer plans are required for our review and approval prior to construction. (offsite and onsite) 11. Prior to construction a sewer lateral connection sketch must be approved for non-residential connections (commercial, industrial, institutional). Comments: The site plan does not show or incorrectly shows: meter locations water line locations sewer line locations easements water line size sewer line size expected wastewater flows expected water demands SITE REVIEW CON14ENTS - FOREST LAKES TOWNHOUSE A PRELIMINARY PLAN 1. As we have discussed, please realign the entrance across from Cross Timbers Road. As we have agreed, instead of dedication at this time, please note reservation for potential future extension to serve other properties. 2. Read carefully comments by Virginia Department of Transportation. Incorporate those relevant to this plan. 3. Revise the plan to include the following: a. Travelway minimum width is measured excluding the gutter pan; b. Once the entrance is revised, avoid proposing parking spaces which involve backing in that area; C. Note the benchmark used; d. Note owner, zoning and present use of adjacent parcels; e. Note building setback lines and separation requirements; f. Note the building square footage by groupings and total; g. Note the maximum amount of impervious cover on the site; h. Note any areas of existing slope 250 or greater; i. Note proposed trash containers; j. Show a pathway for pedestrian access to the recreation complex. Provided that you meet the stated deadline for revisions, and the revisions are satisfactory, your plan/plat will be heard by the Planning Commission on February 23, 1988, 7:30 p.m., Meeting Room #7, Second Floor, County Office Building, 401 McIntire Road. THE APPLICANT OR A REPRESENTATIVE MUST BE PRESENT AT THE PLANNING COMMISSION MEETING. The Planning Commission will not review plans/plats which occasion sight distance, grading, or other easements (excluding those for public utilities), without evidence from the developer that permission is obtainable. This evidence must be submitted by the revision deadline for this item to proceed to the Planning Commission at the above -noted date. Thank you. AMP/jmc CC: Bill Roudabush Robert H. Fitz, Jr. COUNTY OF ALBEMARLE Dept. of Planning & Community Development 401 McIntire Road Charlottesville, Virginia 229014596 (804) 296-5823 TO: Forest Lakes Associates ���© FROM: Amelia M. Patterson, PlannerV"I" DATE: January 25, 1988 RE: Site Review Committee Comments - Forest Lakes Townhouse A Preliminary Plan The Site Review Committee reviewed the above referenced plan/plat on January 21, 1988. Pertinent comments from the following agencies are attached: o i Planning Department - contact Planner - 296-5823 County Engineer - contact Steve Cresswell - 296-5861 all, Fire Officer - contact Bob Jenkins - 296-5832 o/ Service Authority - contact Lou Rossie - 296-5810 o Health Department - contact Jack Collins - 295-0161 q," Virginia Department of Transportation - contact Jeff Echols - 296-5102 o Soil Conservation Service - contact Gordon Yager - 296-5815 obi Watershed Manager - contact William Norris - 296-5841 ©/ Zoning - contact Kathy Brittain - 296-5875 The Committee's comments will reflect information available at the time the plan/plat was reviewed, but should not be considered final. Please revise the plan/plat to include the attached comments and submit five (5) copies of the revised plan/plat no later than 5:00 p.m. February 1, 1988. No plan/plat will be scheduled for Planning Commission review until all necessary information and items marked with ** on the comments are submitted, in a form satisfactory to the Director of Planning and Community Development. COUNTY OF ALBEMARLE DepL of Planning & Community Development 401 Mdnn.e Road Charlottesville, Vkgmia 229014596 (804) 296-SBM February 5, 1988 F. A. and Hattie J. Brown George E. and Mildred M. Byerly Stephen H., Jr. and Fay A. Clark Willard E. and Virginia I. Hall Holly Memorial Gardens, Inc. Hollymead Citizens Association, Inc. Hollymead Estate Land Trust Franklin D. or Lena E. Jones Maple Grove Christian Church Russel D. Mooney, Jr. Trustee Nellie L. Moubry Thelma 4 Y. F. Oesterheld Yerby Fred, Jr. and Birtis S. Oesterheld R. L. Beyer Construction, Inc. Donald L. 6 Jimmie L. Reid Theodore J. 6 Shirley S. Sklany Virginia Land Trust Joseph W. Wright, Jr. Virginia Power RE: Forest Lakes Phase I, Section II Preliminary Plat; and Forest Lakes Townhouse Development Phase I "A" Preliminary Site Plan Ladies and Gentlemen: This letter is to notify you as an adjacent property owner that a site plan and subdivision plat have been submitted for approval for the development of property described as follows: 1. Forest Lakes Phase I. Section iI Preliminary Plat - Proposal to create 99 lots on 41.4 acres. The proposed use for this development is single family residential detached (19.8 acres) and single family residential - villas (14.6 acres). 7.87 acres are provided as common open space. The property Is located off Route 29 North, at its intersection with Route 649 in Hollymead. Tax Map 46, Parcels 29, 29D and 29E. Zoned R-4, Residential. Rivanna Magisterial District. Adjacent Property Owners February 5, 1988 Page 2 2. Forest Lakes Townhouse Development Phase I "A" Preliminary Site Plan - Proposal to locate 24 townhouse units on +7 acres, w th a resulting density of 3.4 dwelling unite per acre. The development will be serviced by internal private roads, while 48 parking spaces will be provided. The property is located off Route 29 North, at the intersection of Route 649 in Hollymead. Tax Map 46, Parcel 29E. Zoned R-4, Residential. Rivanna Magisterial District. The Albemarle County Planning Commission will act on these submittals and receive conents from the public at their meeting on Februag 23, 1988, 7:30 p.m., Meeting Room 47, Second Floor, County office Building, 401 McIntire Road, Charlottesville, Virginia. If you wish to attend the meeting, you may call this office during the week of the meeting to ask the tentative time the item will appear on the agenda. The site plan and subdivision plat am available for your review in the Albemarle County Planning Office, Second Floor, 401 McIntire Road, Charlottesville, Virginia. In order to aid the Planning staff in the review of the above referenced plan, we respectfully request that any questions, comments or observations that you may have be submitted in writing to us in order that we may react to those questions prior to the Planning Commission's review of the site plan and subdivision plat. If you should have any questions, please do not hesitate to contact me. Sincerely, rn. P,t .. Amelia M. Patterson Planner AMP/jmc COUNTY OF ALBEMARLE Dept. of Planning & Community Development 401 McIntire Road Charlottesville, Virginia 22901.4596 (804) 296-5823 February 5, 1988 Forest Lakes Associates 500 Faulconer Drive Charlottesville, VA 22901 RE: Forest Lakes Phase I, Section II Preliminary Plat; and Forest Lakes Townhouse Development Phase I "A" Preliminary Site Plan I Dear Sir or Madam: i This letter is to notify you that your site plan and subdivision plat will be heard by the Albemarle County Planning Commission on February 23, 1988, 7:30 p.m., Meeting Room #7, Second Floor, County Office Building, 401 McIntire Road, Charlottesville, Virginia. ■1 You will receive a tentative agenda and staff report one week prior to the Planning Commission meeting. YOU OR YOUR REPRESENTATIVE MUST BE PRESENT FOR THE PLANNING COMMISSION MEETING. Sincerely, Amelia M. Patterson' Planner AMP/jmc CC: Robert H. Fitz, Jr., Clower Associates History: • SP-156 North Corporation/Hollymead Planned Community for a Planned Unit Development with a total of 740 residential units, was approved by the Board of Supervisors on May 8, 1972. The plan proposed a future school site, recreation area, commercial area, and a mixture of residential uses. (Tax Map 46, Parcel 29) e SP-77-70 Dr. Charles W. Hurt was approved by the Board of Supervisors on December 14, 1977. This proposed a general reduction in the density of the Phase I development (a total of 650 dwelling units) and a redistribution of open space. • ZMA-53-19 H011ymeaa Lana 'trust ana A1Demarle banK ana Trust Company was approved by the Board of Supervisors on February 1, 1984. This rezoned 296 acres from R-1, Residential to R-4, Residential with the proffer of a maximum residential density of 1.7 dwelling units per acre, and then rezoned 23 acres from R-1, Residential to R-15,-Residential. (Tax Map 46, parcel 29) • ZMA-85-20 Hollymead Land Trust and Tri-Ton, Incorporated was approved by the Board of Supervisors on November 6, 1985. This rezoned 17.8 acres from R-1, Residential to HC, Highway Commercial with proffer. Those relevant proffers for Route 29 and Route 649 are incorporated into the Forest Lakes Plat. (Tax Map 32, Parcels 42 and 36) • The Hollymead Right-of-way Dedication Final Plat was approved by the Planning Commission on February 15, 1983 and was not pursued by the applicant. This plat proposed dedication of right=of-way for the roadway over the Hollymead Lake Dam. On February 5, 1986, staff signed a plat which divided Tax Map 46, Parcel 29 into three parcels: +27 acres, +55 acres and +101 acres, and added a 21 acre portion to become a part of Parcel 34. on 91 acres was 1983. 0 for 99 cluster lots on September 26, r- School Impact: Project enrollment from this townhouse development is 12 students, who will attend Hollymead, Jack 'i Jouett and Albemarle High Schools. Environmental Conditions (topography, soils, watershed j impoundment): Moderately rolling from the Parkway down to the I proposed lake (previously drained). Soils consist of Glenelg loam and Elioak loam. Both soils are deep and well drained. The major hazard when working with these soils is that they are very erosive. This project is located outside watersupply watershed -, management areas. r Utilities; Fire Protection: An eight -inch water line is located within the right of way for Powell Creek Road. Fireflow from the nearest hydrant is 1040 gallons per minute at 20 psi, and from (' the hydrant at Route 29 is 1960 gallons per minute at 20 psi. An 18 inch sewer line is located + 4850 distant. Fireflow requirements will be based on ISO stipulations and as approved by this office. Type of construction and square footage of buildings will be needed for evaluation. Stormwater Detention/Runoff Control: Stormwater detention will be provided with the proposed lake. Transportation (condition of roads, Virginia Department of Transportation, and County Engineer comments): The Virginia Department of Transportation comments "A 12 foot wide 100 foot long right turn lane with a 100 foot taper lane with CG-6 is adequate for this entrance ... The Department recommends that there be one lane inbound (16 feet wide) and two lanes outbound (24 feet wide) for this entrance ... Any entrance aligning across from a future crossover on Timberwood Parkway is required to a minimum of 375 feet of sight distance in all directions." RECOMMENDED CONDITIONS OF APPROVAL: 1. The final plan will not be signed until the following conditions have been met: a. County Engineering approval of road and drainage plans and calculations for the following roadways: 1. Forest Lakes Parkway (Timberwood Boulevard) 2. Meadowcreek Parkway (Timberwood Parkway); b. County Engineering approval of stromwater detention plans and calculations to include installation and design of an emergency spillway on the existing dam; C. Virginia Department of Transportation approval of road and drainage plans and calculations, and approval of detention facilities which abut future State roads; d. Virginia Department of Transportation approval of Route 29 improvements and issuance of a commercial entrance permit in accordance with letter of October 8, 1987; e. Issuance of an Erosion Control Permit; f. Issuance of an Operations and Maintenance Permit on the existing dam; g. Albemarle County Service Authority approval of final water and sewer plans onsite and offsite; h. Fire Officer approval; i. Planning staff approval of: 1. Landscape plan to include conservation plan; 2. Recreation plan to include relocating the tot lot from the parking island; 3. Recordation of plat dedicating right of way as necessary. 2. A certificate of occupancy will not be issued until the following condition has been met: a. Final Fire Officer approval. History: See attached sheet. Also, Forest Lakes Phase I, Section I Preliminary Plat was approved by the Planning Commission on November 10, 1987. The Final Plat has been to Site Review and is pending necessary preliminary approvals. Comprehensive Plan Recommendation: This property is within the Community of Hollymead, and is designated for low density (1-4 dwelling units per acre) residential use. 2 r-• Ir STAFF PERSON: AMELIA M. PATTERSON -- STAFF REPORT: FEBRUARY 23, 1988 FOREST LAKES TOWNHOUSE PHASE I, SECTION A PRELIMINARY SITE PLAN Proposal: To locate 24 townhouse units in four unit clusters on +7 acres, with a resulting density of 3.4 dwelling units per acre. A total of 64 parking spaces are proposed, of which 48 are required. An internal private road is proposed off the proposed Timberwood Parkway. Zoned R-4, Residential. _ Location: Off the east side of Route 29 North and south of Proffit Road (Route 649), off the west side of the Timberwood (Meadowcreek) Parkway, adjacent to the north of a previously drained lake. Tax Map 46, Parcel 29E. Rivanna Magisterial District. STAFF COMMENT: The Planning Commission may recall approval of the Forest Lakes, Phase I, Section I Preliminary Plat on November 10, 1987. The applicant is presently working on approvals for drainage, roads, water and sewer plans to include this townhouse Section A. Permission from Virginia Power has been received for proposed improvements in their 120 foot easement. The applicant agreed to revise the plan to relocate the entrance in accordance with site review comments by Planning, Engineering and the Virginia Department of Transportation. The entrance shift from the western corner of the property to the eastern corner aligns the entrance with a major loop road, Cross Timbers Road, and eliminates the additional crossover on the Parkway. In addition, the applicant agreed to reserve right-of-way from the entrance road along the eastern boundary to potentially serve future development of adjacent parcels owned by others. The provision of access to the two immediately adjacent parcels (29N2 and 29N) which only have Proffit Road frontage, would eliminate/reduce additional entrances onto Route 649 and provide access to the Parkway at a crossover. The adjacent previously drained lake is proposed to be filled and to serve as stormwater detention. Where possible on the site perimeter, existing trees will be preserved. Planning staff recommends relocating a tot lot presently proposed in a parking circle. There are several alternative locations which would be suitable to staff. This plan will meet the requirements of the Zoning Ordinance, and staff recommends approval subject to the following: 1 Mr. Frank Kessler February 24, 1988 Page 3 Once tentative approvals are secured, the final plan shall be submitted to this Department, as stated above. The final plan mylar can be signed at the scheduled Site Review Meeting if after staff review, the final plan meets all ordinances and conditions of approval. If you should have any questions or comments regarding the above noted action, please do not hesitate to contact me. Sincerely, Amelia M. Patterson Planner AMP/jmc cc: Clower Associates, Inc. Bill Roudabush Steve Cresswell Jeff Echols Lou Rossie Bob Jenkins Kathy Brittain r- Mr. Frank Kessler February 24, 1988 Page 2 f. Issuance of an Operations and Maintenance Permit on the existing dam; g. Albemarle County Service Authority approval of final water and sewer plans onsite and offsite; r_ h. Fire Officer approval; 1. Planning staff approval of the following: 1. Landscape plan to include conservation plan; 2. Recreation plan to include relocating the tot lot from the parking island; 3. Recordation of plat dedicating right of way as necessary. 2. A certificate of occupancy will not be issued until the following condition has been met: a. Final Fire Officer approval. 3. The final plan may be administratively approved. In order to be eligible for administrative approval by the agent, a final site development plan shall be submitted on a submittal deadline with the appropriate fee within six (6) months of Planning Commission approval of the preliminary plan. In any case, the final site development plan shall be submitted within one (1) year of the Planning Commission's approval of the preliminary plan or the approval shall expire. During the above time period, the applicant shall work to satisfy the conditions of preliminary site development plan approval. The applicant shall have the appropriate agency notify this Department in writing that the applicable conditions have been met. To obtain tentative approvals for the final site development plan l from the agencies represented on the Site Review Committee, the applicant shall submit the appropriate plans and materials to each agency, individually, for their review. Once the plans have been tentatively approved by each agency, the applicant shall have each agency notify the Planning Department in writing, that tentative approval has been secured. i or .g �/11C1T11P COUNTY OF ALBEMARLE Dept. of Planning & Community Development 401 McIntire Road Charlottesville, Virginia 22901-4596 (804) 296-5823 February 24, 1988 Frank Kessler Forest Lakes Associates 500 Faulconer Drive Charlottesville, VA 22901. RE: Forest Lakes Townhouse Section A Preliminary Plan: Tax Map 46, Parcel 29E; Route 29 North (SDP-88-003) Dear Mr. Kessler: At their meeting on February 23, 1988, the Albemarle County Planning Commission unanimously approved the above -noted site plan. This approval is subject to the following: 1. The final plan will not be signed until the following conditions have been met: a. County Engineering approval of road and drainage plans and calculations for the following roadways: 1. Forest Lakes Parkway (Timberwood Boulevard) 2. Meadowcreek Parkway (Timberwood Parkway) b. County Engineering approval of stormwater detention plans and calculations to include installation and design of an emergency spillway on the existing dam; C. Virginia Department of Transportation approval of road and drainage plans and calculations, and approval of detention facilities which abut future State roads; d. Virginia Department of Transportation approval of Route 29 improvements and issuance of a commercial entrance permit in accordance with letter of October 8, 1987; e. Issuance of an Erosion Control Permit; IV Applied Technology and Engineering, P.C. P.O. Box 6217 Charlottesville, Virginia 22906 (804) 977-1498 Steve Cresswell, P. E. Albemarle County Department of Engineering 401 McIntire Road Charlottesville, Virginia 22901 March 15, 1989 Re: Forest Lakes Dates B, C & D Dear Steve: We have received the letter from Dan Roosevelt (by Jeff Echols) to you dated March 3, 1989 regarding the outflow calculations for the subject dams. I have talked with Jeff Echols and Mike Via in order to better understand their concerns, Mike Via said that he feels comfortable that the roads are not in danger of flooding or being washed out, but would like some record of our conversations and calculations regarding the hydraulics of the outflow structures. We also observed that the impoundment structures are not the road impoundment structures and that we have provided emergency spillways that lead to separate storm sewers under the road impoundments that have the same flow capacity as the primary spillways for the dams, which were designed to handle a 100 year flow. As you know, we made the same observations that VDOT did regarding the simplifying assumptions and limitations of the flood routing model before we submitted the flood routing calculations to you. As discussed at that time, we believe that the computer model results are completely within the tolerances and accuracies of the process of predicting hydrological conditions. There are no exact methods to predict rainfall or runoff. The initial assumptions in the Rational method of computing rainfall runoff are critical to the reasonableness of the predictions derived from that base. For instance, we computed a weighted runoff coefficient of 0.3631 but rounded it off to 0.4. This alone can affect the peak rate of runoff by 10%. The time of concentration can also affect the peak rate. So, we need to keep this in mind when we preform more accurate engineering calculation on the data. I do not have to remind you or VDOT people of this but it needs to be pointed out to the uninitiated. In order to test our belief that the ROUT calculations are within reason, we have reviewed the hydraulic profile, the peaking time for the various flood stages, and have done hydraulic calculations for the individual pond -to -pond piping for the four pond system. ROUT, the flood routing model, analyzes each component of the outflow structure individually and uses the controlling component to calculate pond outflow. In the case of the horizontal pipe, ROUT uses the equation from which the nomographs for outlet control, found in the VDOT Drainage Manual, were derived. In the four pond system, pond A is the only one that is indicated to operate with the horizontal pipe in outlet control. Therefore, the first check we made was on dam A outflow pipe in submerged outlet control according to Chart 9, VDOT Drainage Manual. In order to do this the assumption was made, as in ROUT, that the 48" riser has no affect on the horizontal pipe. A copy of Chart 9 with the lines marked on it is attached. This Chan is limited to 20' of head, but indicates that about 95 cfs can be passed through a 30" concrete pipe with a 20' head. This confirms the ROUT calculation. As another check, we analyzed the riser and pipe as a hydraulic pipe system with the elevation difference between the water levels in the two pond as the driving force. Here we assumed that the two ponds reach maximum flood level at the same time, as a worst case situation, when they actually occur about 20 minutes apart. We modeled the 48" riser inlet two ways, one as a 30" orifice and second as as a 48" orifice. The 30" orifice model was done because the riser has an anti -vortex, precast concrete top with a DI-7 inlet grate, and these two cases should give a range from worst to best situation. These two cases were run on a spread sheet program developed for this type of pipe flow analysis with a range of flows to compute the corresponding head. The two cases were graphed and actual heads were plotted on the curves. The calculation sheets and graph are attached. Case 2 is similar to the ROUT assumptions, and with the assumed tail water at one half the pipe diameter (which gives a driving head of 24.32 feet), the flow of 96.5 is exactly what ROUT predicted. However, the actual head is about 21.8' and the flow for that is 85 cfs. Case 1 is the worst case and at 21.8' of head the flow is 81.5 cfs, or about 85% of the best case situation. As with all such calculations many simplifying assumptions must be made, but looking at the outside parameters, the ROUT calculations seem to be reasonable. The outflow pipe for dam B does not become submerged, even if the 100 year flood level occur at the same time. The outflow pipe from pond C would become submerged by about one foot in worst case, but would not substantially affect the system. The outflow pipe from pond D is not expected to be submerged under any anticipated situations. Based upon the above calculations, we believe that the dams will function as predicted, within the accepted limitations of the current state of the art of hydrology. If you have questions, please call. Thank you for your help on this matter. Sincerely, ohn W. Greene. P. E. enclosures copy: Denise Etheridge, The Kessler Group Applied Technology and f ineering, P.C. 0. P. ���Box 6217 Charlottesville, Virginia 22906 Phone: (804) 977-1498 JOB- - FORc.- SHEET NO --. - CALCULATED BY CHECKED SY j o7AL_ , C ATC.NHEu7 = I Q 0 . IAC C i3eFcrm - D, 3 LAKES 194-7 ICI OF p pp W• C DATE DATE tvwj 37-3v' CHoN.ucL- G SfPs _ /0.9 MIA/. i �- Ls- 3.5 N2 - r I I n . mo I99• S CFs .'Clop` ZgO,-7 ...e-A Y1 � yo Ac. cz c-.(o, , zl.os'!a_-`. 0,123 - I 1740 'de. @- c-, 301 6G.3z90 o. /989L ., .. ��: �. D✓C2aa A/D ZOD� @ SII/v �- �I S; M/N� � ; _ L _ �-... I37o ,Piv[LO L. (O Fes 4 Z3,(o 35 Hit lili , goo F (JpQMAL, %70OC CEVBC - 5!73�_- io ra g1614 47V. 7rf C m IS 24 E w. I j G.-t Sf77. o i cKEST of oan z 479.o - v HYDROGRAPH TIME OF CONCENTRATION = 24.0 MIN STORM DURATION = 24.0 MIN TIME Q2 Q5 Q10 Q25 Q50 Q100 j (MIN) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) 0.0 0.00 0.00 0.00 0.00 0.00 0.00 2.0 16.15 20.27 23.12 27.42 30.27 33.88 4.0 32.30 40.53 46.23 54.85 60.55 67.77 6.0 48.45 60.80 69.35 82.27 90.82 101.65 8.0 64.60 81.07 92.47 109.69 121.09 135.53 10.0 80.75 101.33 115.58 137.12 151.37 169.42 l l 12.0 96.90 121.60 138.70 164.54 181.64 203.30 14.0 113.05 141.87 161.82 191.96 211.91 237.18 f 16.0 129.20 162.13 184.93 219.39 242.19 271.07 l 18.0 145.35 182.40 208.05 246.81 272.46 304.95 20.0 161.50 202.67 231.17 274.23 302.73 338.83 22.0 177.65 222.93 254.28 301.66 333.01 372.72 ( 24.0 193.80 243.20 277.40 329.08 363.28 406.60 l 26.0 184.13 231.06 263.56 312.66 345.15 386.31 28.0 174.46 218.93 249.72 296.24 327.02 366.02 ` 30.0 164.79 206.79 235.87 279.82 308.90 345.73 32.0 155.12 194.66 222.03 263.40 290.77 325.44 34.0 145.45 182.52 208.19 246.97 272.64 305.15 36.0 135.78 170.39 194.35 230.55 254.51 284.86 l38.0 126.11 158.25 180.50 214.13 236.39 264.57 40.0 116.43 146.11 166.66 197.71 218.26 244.28 42.0 106.76 133.98 152.82 181.29 200.13 224.00 44.0 97.09 121.84 138.98 164.87 182.00 203.71 46.0 87.42 1 j.71 125.13 148.45 163.87 183.42 48.0 77.75 97.57 111.29 132.03 145.75 163.13 I 50.0 68.08 85.44 97.45 115.60 127.62 142.84 52.0 58.41 73.30 83.61 99.18 109.49 122.55 54.0 48.74 61.16 69.77 82.76 91.36 102.26 56.0 39.07 49.03 55.92 66.34 73.24 81.97 58.0 29.40 36.89 42.08 49.92 55.11 61.68 60.0 19.73 24.76 28.24 33.50 36.98 41.39 r 62.0 10.06 12.62 14.40 17.08 18.85 21.10 64.0 0.39 0.49 0.55 0.66 0.73 0.81 fl ************************************************************************** * ROUT VERSION 5.2 ************************************************************************** * PROJECT : FOREST LAKES DAM A 100 YR. * DATE 4-18-88 ************************************************************************** f STRUCTURE 1 STRUCTURE 2 STRUCTURE 3 1: TYPE ----------- 3: RISER ----------- 1: WEIR ----------- WEIR: 2: ELEVATION (FT) 0.00 477.00 0.00 f 3: LENGTH (FT) 0.00 10.00 0.00 4: COEFFICIENT 0.00 2..50 0.00 RISER: 5: ELEVATION (FT) 473.00 0.00 0.00 6: DIAMETER (IN) 48.00 0.00 0.00 7: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 8: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 9: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 10: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 ' 11: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 12: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 PIPE: 13: INVERT ELEVATION (FT) 458.00 0.00 0.00 1. 14: DIAMETER (IN) 30.00 0.00 0.00 15: ORIFICE DIAMETER (IN) 30.00 0.00 0.00 16: LENGTH (FT) 250.00 0.00 0.00 17: MANNING'S N 0.013 0.000 0.000 18: SLOPE (FT/FT) 0.031 0.000 0.000 19: ENTRANCE LOSS COEFFICIENT 0.50 0.00 0.00 SURFACE: 20: INITIAL ELEVATION (FT) 473.00 i STORAGE POND CHARACTERISTICS: SECTION ELEVATION AREA (FEET) (ACRE)- 1 459.67 0.00 (CALCULATED) 2 462.00 0.70 3 466.00 1.90 4 470.00 3.30 5 474.00 5.00 I_ 6 476.00 6.00 7 480.00 8.70 * PROJECT : FOREST LAKES DAM A 100 YR. * DATE : 4-18-88 I ************************************************************************** I1 CONTROL: RW = RISER ACTING AS A WEIR RO = RISER ACTING AS AN ORIFICE _ PI = HORIZONTAL PIPE IN INLET CONTROL PO = HORIZONTAL PIPE IN OUTLET CONTROL TIME INFLOW RISER WEIR TOTAL ELEV STORAGE (MIN) (CFS) (CFS) (CFS) (CFS) (FT) (AC -FT) ------------------------------------------------------------- 0 0.00 0.0 0.0 0.00 473.00 28.16 2 33.88 0.1 RW 0.0 0.05 473.01 28.21 4 67.77 0.4 RW 0.0 0.35 473.04 28.35 6 101.65 1.1 RW 0.0 1.14 473.09 28.57 8 135.53 2.6 RW 0.0 2.64 473.16 28.88 10 169.42 5.1 RW 0.0 5.06 473.24 29.27 I 12 203.30 8.6 RW 0.0 8.59 473.35 29.74 14 237.18 13.4 RW 0.0 13.38 473.47 30.30 ' 16 271.07 19.6 RW 0.0 19.57 473.60 30.93 18 304.95 27.3 RW 0.0 27.26 473.75 31.64 20 338.83 36.5 RW 0.0 36.54 473.91 32.41 22 372.72 47.4 RW 0.0 47.45 474.09 33.25 24 406.60 60.0 RW 0.0 60.01 474.27 34.16 26 386.31 72.9 RO 0.0 72.89 474.45 35.05 28 366.02 76.8 RO 0.0 76.80 474.61 35.86 I 30 345.73 80.2 RO 0.0 80.20 474.76 36.60 �. 32 325.44 83.2 RO 0.0 83.16 474.89 37.28 34 305.15 85.7 RO 0.0 85.74 475.01 37.90 36 284.86 88.0 RO 0.0 87.99 475.11 38.45 38 264.57 89.9 RO 0.0 89.93 475.21 38.95 t 40 244.28 91.6 RO 0.0 91.60 475.29 39.39 42 224.00 93.0 RO 0.0 93.02 475.36 39.77 44 203.71 94.2 RO 0.0 94.19 475.42 40.09 46 183.42 95.1 RO 0.0 95.15 475.47 40.36 48 163.13 95.9 RO 0.0 95.89 475.51 40.57 j 50 142.84 96.4 PO 0.0 96.37 475.54 40.72 52 122.55 96.4 PO 0.0 96.41 475.56 40.82 54 102.26 96.4 PO 0.0 96.42 475.57 f-- 40.86 56 81.97 96.4 PO 0.0 96.42 475.56 40.85 58 61.68 96.4 PO 0.0 96.39 475.55 40.78 60 41.39 96.2 RO 0.0 .96.18 475.53 40.65 62 21.10 95.5 RO 0.0 95.53 475.49 40.47 j 64 0.81 94.7 RO 0.0 94.67 475.45 40.23 r ************************************************************************** * ROUT VERSION 5.2 ************************************************************************** * PROJECT : FOREST LAKES DAM A 10 YR. * DATE : 4-18-88 STRUCTURE 1 ----------- STRUCTURE 2 STRUCTURE 3 ----------- 1: TYPE 3: RISER ----------- 1: WEIR WEIR: 2: ELEVATION (FT) 0.00 477.00 0.00 3: LENGTH (FT) 0.00 10.00 0.00 4: COEFFICIENT 0.00 2.50 0.00 RISER: 5: ELEVATION (FT) 473.00 0.00 0.00 6: DIAMETER (IN) 48.00 0.00 0.00 7: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 8: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 9: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 10: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 11: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 12: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 PIPE: 13. INVERT ELEVATION (FT) 458.00 0.00 0.00 14: DIAMETER (IN) 30.00 0.00 0.00 IS: ORIFICE DIAMETER (IN) 30.00 0.00 0.00 16: LENGTH (FT) 250.00 0.00 0.00 17: MANNING'S N 0.013 0.000 0.000 18: SLOPE (FT/FT) 0.031 0.000 0.000 19: ENTRANCE LOSS COEFFICIENT 0.50 0.00 0.00 SURFACE: 20: INITIAL ELEVATION (FT) 473.00 STORAGE POND CHARACTERISTICS: SECTION ELEVATION AREA ----------------------------- (FEET) (ACRE) 1 459.67 0.00 (CALCULATED) 2 462.00 0.70 3 466.00 1.90 4 470.00 3.30 5 474.00 5.00 6 476.00 6.00 7 480.00 8.70 r * PROJECT : FOREST LAKES DAM A 10 YR. * DATE : 4-18-88 ************************************************************************** ( CONTROL: RW = RISER ACTING AS A WEIR RO = RISER ACTING AS AN ORIFICE ^ PI = HORIZONTAL PIPE IN INLET CONTROL l` PO = HORIZONTAL PIPE IN OUTLET CONTROL TIME INFLOW RISER WEIR TOTAL ELEV STORAGE r (MIN) ------------------------------------------------------------- (CFS) (CFS) (CFS) (CFS) (FT) (AC -FT) i 0 0.00 0.0 0.0 0.00 473.00 28.16 2 23.12 0.0 RW 0.0 0.03 473.01 28.20 4 46.23 0.2 RW 0.0 0.20 473.03 28.29 6 69.35 0.7 RW 0.0 0.65 473.06 28.44 8 92.47 1.5 RW 0.0 1.50 473.11 28.65 _ i' 10 115.58 2.9 RW 0.0 2.88 473.17 28.92 12 138.70 4.9 RW 0.0 4.90 473.24 29.25 14 161.82 7.7 RW 0.0 7.66 473.32 29.63 16 184.93 11.2 RW 0.0 11.24 473.42 30.06 18 208.05 15.7 RW 0.0 15.71 473.52 30.55 20 231.17 21.1 RW 0.0 21.14 473.63 31.08 22 254.28 27.6 RW 0.0 27.57 473.76 31.66 24 277.40 35.0 RW 0.0 35.02 473.89 32.29 26 263.56 42.9 RW 0.0 42.88 474.02 32.91 28 249.72 50.4 RW 0.0 50.40 474.13 33.47 30 235.87 57.5 RW 0.0 57.46 474.24 33.98 i 32 222.03 64.0 RW 0.0 63.97 474.33 34.43 34 206.19 69.9 RW 0.0 69.87 474.41 34.83 36 194.35 73.5 RO 0.0 73.53 474.48 35.18 38 180.50 75.0 RO 0.0 75.01 474.54 35.48 40 166.66 76.3 RO 0.0 76.26 474.59 35.74 42 152.82 77.3 RO 0.0 77.30 474.63 35.96 44 138.98 78.1 RO 0.0 78.15 474.67 36.15 46 125.13 78.8 RO 0.0 78.80 474.70 36.29 48 111.29 79.3 RO 0.0 79.27 474.72 36.39 50 97.45 79.6 RO 0.0 79.57 474.73 36.46 52 83.61 79.7 RO 0.0 79.70 474.74 E- 36.49 54 69.77 79.7 RO 0.0 79.67 474.73 36.48 56 55.92 79.5 RO 0.0 79.45 474.72 36.43 58 42.08 79.1 RO 0.0 79.07 474.71 36.35 60 28.24 78.5 RO 0.0 78.50 474.68 36.22 62 14.40 77.8 RO 0.0 77.76 474.65 36.06 64 0.55 76.8 RO 0.0 76.84 474.61 35.87 Applied Technology and E 'neering, P.C. P. O. Box 6217 4v $MEET NO. �' �' OF JCharlottesville, Virginia 22906 CALCULATED BY �✓�� DATES Phone: (804) 977-1498 CHECKED BY DATE SCALE 1'1,i1)RnuLlc dtlLCUL,1Tonic,, 1=otZ 4B'" R15G2 ` 30" P/PC-' r � 00 1-4 f C —�- ! I t i !_.._, -- v� - .00aotr, 1/.S4 41- R9 xlo A - k 3. � ( - ( - 1 - 3.30p Y to C �17n� ;,�R6,,' !0 8(� tl �, gq�yn�l .i._. J _ ..{... 'F ... I -- -7 � _,;/ •,� Ems. ., _., __. _ � _ = : , 1� YID Cri/��n, -/ �� 43, VI!• ( ul..•''AJ . . APPued Teennoiogy and engineering, P.C. P. O. BOX 6217 SHEET NO. OF I Charlottesville, Virginia 229O6 CALCULATED BY � • �_ DATE � I " Q _ 9Q Phone: (804) 977-1498 CHECKED BY DATE oen�c l¢TAL(~ATC4Ar49F�_ }Iq.p I h L— C CifiFogcc — . 0.3 ?` t = • 0Vc59 rF.4 01O Zoof (R S /o -�S. M/N.. . 17.3O+ CRc Nassu Ci SIFPS ° .10.8 MlM, I too. j `i1m l99• $ CFS y loo s 79Y3.7 Gi . i !CAF7tR.% Z /fie- iC` .c`•.9 12.G3�ii 1005.79: _1 i 1^ 'lam Ac. C 4 Zl.ob9a `. O /Z(o3 72te Qe. Cd. c=, 3 i,¢.z`= o. 1989 _ o. 3��i U5� . o:•'.� tom: �VG.CLANO 2L1O� SJo J9104p4mvfL L S FG$ 137o prR[ O C . [n FPS 5.35 1n�i+t �o = 277.'i cFs q)eo' yoG.G GFS 1�oRnnL. Proc LEVEL y73 � /n Y,e ulc.14 = 474.7q I r toe YR Ai4W q75. S7 CME.RCwENC`t 5PIL4_w4v .' -q77. o .. C9GjT vF oAM z 47S..o .- 'f.G'.t -.. FvO+)A' V rJo7 r I HYDROGRAPH TIME -OF -CONCENTRATION = 24.0 MIN STORM DURATION = 24.0 MIN TIME Q2 Q5 Q10 Q25 Q50 Q100 (MIN) (CFS) (CFS) (CFS) ----- (CFS) ----- (CPS) ----- (CFS) ----- ----- 0.0 ----- 0.00 ----- 0.00 0.00 0.00 0.00 0.00 I I 2.0 16.15 20.27 23.12 27.42 30.27 33.88 4.0 32.30 40.53 46.23 54.85 60.55 67.77 6.0 48.45 60.80 69.35 82.27 90.82 101.65 8.0 64.60 81.07 92.47 109.69 121.09 135.53 10.0 80.75 101.33 115.58 137.12 151.37 169.42 12.0 96.90 121.60 138.70 164.54 181.64 203.30 (- 14.0 113.05 141.87 161.82 191.96 211.91 237.18 16.0 129.20 162.13 184.93 219.39 242.19 271.07 18.0 145.35 182.40 208.05 246.81 272.46 304.95 20.0 161.50 202.67 231.17 274.23 302.73 338.83 22.0 177.65 222.93 254.28 301.66 333.01 372.72 24.0 193.80 243.20 277.40 329.08 363.28 406.60 26.0 184.13 231.06 263.56 312.66 345.15 386.31 28.0 174.46 218.93 249.72 296.24 327.02 366.02 30.0 164.79 206.79 235.87 279.82 308.90 345.73 32.0 155.12 194.66 222.03 263.40 290.77 325.44 34.0 145.45 182.52 208.19 246.97 272.64 305.15 36.0 135.78 170.39 194.35 230.55 254.51 284.86 38.0 126.11 158.25 180.50 214.13 236.39 264.57 40.0 116.43 146.11 166.66 197.71 218.26 244.28 42.0 106.76 133.98 152.82 181.29 200.13 224.00 44.0 97.09 121.84 138.98 164.87 182.00 203.71 46.0 87.42 109.71 125.13 148.45 163.87 183.42 48.0 77.75 97.57 111.29 132.03 145.75 163.13 50.0 68.08 85.44 97.45 115.60 127.62 142.84 52.0 58.41 73.30 83.61 99.18 109.49 122.55 54.0 48.74 61.16 69.77 82.76 91.36 102.26 56.0 39.07 49.03 55.92 66.34 73.24 81.97 58.0 29.40 36.89 42.08 49.92 55.11 61.68 60.0 19.73 24.76 28.24 33.50 36.98 41.39 62.0 10.06 12.62 14.40 17.08 18.85 21.10 64.0 0.39 0.49 0.55 0.66 0.73 0.81 * ROUT VERSION 5.2 ************************************************************************** * PROJECT : FOREST LAKES DAM A 100 YR. * DATE : 4-18-88 ************************************************************************** STRUCTURE 1 STRUCTURE 2 STRUCTURE 3 1: TYPE 3: RISER 1: WEIR WEIR: 2: ELEVATION (FT) 0.00 477.00 0.00 3: LENGTH (FT) 0.00 10.00 0.00 4: COEFFICIENT 0.00 2.50 0.00 RISER: 5: ELEVATION (FT) 473.00 0.00 0.00 6: DIAMETER (IN) 48.00 0.00 0.00 7: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 8: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 9: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 10: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 11: ORIFICE ELEVATION (FT) 0.00 0.00 0.00 12: ORIFICE DIAMETER (IN) 0.00 0.00 0.00 PIPE: 13: INVERT ELEVATION (FT) 458.00 0.00 0.00 14: DIAMETER (IN) 30.00 0.00 0.00 15: ORIFICE DIAMETER (IN) 30.00 0.00 0.00 16: LENGTH (FT) 250.00 0.00 0.00 17: MANNING'S N 0.013 0.000 0.000 18: SLOPE (FT/FT) 0.031 0.000 0.000 19: ENTRANCE LOSS COEFFICIENT 0.50 0.00 0.00 SURFACE: 20: INITIAL ELEVATION (FT) 473.00 STORAGE POND CHARACTERISTICS: SECTION ELEVATION AREA (FEET) (ACRE) ------------------------------ 1 459.67 0.00 (CALCULATED) 2 462.00 0.70 3 466.00 1.90 4 470.00 3.30 5 474.00 5.00 6 476.00 6.00 7 480.00 8.70 * PROJECT : FOREST LAKES DAM A 100 YR. * DATE,: 4-18-88 CONTROL: RW = RISER ACTING AS A WEIR _ RO = RISER ACTING AS AN ORIFICE PI = HORIZONTAL PIPE IN INLET CONTROL PO = HORIZONTAL PIPE IN OUTLET CONTROL TIME INFLOW RISER WEIR TOTAL ELEV STORAGE (MIN) (CFS) (CFS) (CFS) (CFS) (FT) (AC -FT) ------------------------------------------------------------- 0 0.00 0.0 0.0 0.00 473.00 28.16 2 33.88 0.1 RW 0.0 0.05 473.01 28.21 4 67.77 0.4 RW 0.0 0.35 473.04 28.35 6 101.65 1.1 RW 0.0 1.14 473.09 28.57 8 135.53 2.6 RW 0.0 2.64 473.16 28.88 10 169.42 5.1 RW 0.0 5.06 473.24 29.27 12 203.30 8.6 RW 0.0 8.59 473.35 29.74 14 237.18 13.4 RW 0.0 13.38 473.47 30.30 16 271.07 19.6 RW 0.0 19.57 473.60 30.93 18 304.95 27.3 RW 0.0 27.26 473.75 31.64 20 338.83 36.5 RW 0.0 36.54 473.91 32.41 22 372.72 47.4 RW 0.0 47.45 474.09 33.25 24 406.60 60.0 RW 0.0 60.01 474.27 34.16 26 386.31 72.9 RO 0.0 72.89 474.45 35.05 28 366.02 76.8 RO 0.0 76.80 474.61 35.86 30 345.73 80.2 RO 0.0 80.20 474.76 36.60 32 325.44 83.2 RO 0.0 83.16 474.89 37.28 34 305.15 85.7 RO 0.0 85.74 475.01 37.90 [ 36 284.86 88.0 RO 0.0 87.99 475.11 38.45 38 264.57 89.9 RO 0.0 89.93 475.21 38.95 40 244.28 91.6 RO 0.0 91.60 475.29 39.39 42 224.00 93.0 RO 0.0 93.02 475.36 39.77 44 203.71 94.2 RO 0.0 94.19 475.42 40.09 46 183.42 95.1 RO 0.0 95.15 475.47 40.36 ! 48 163.13 95.9 RO 0.0 95.89 475.51 40.57 i, 50 142.84 96.4 PO 0.0 96.37 475.54 40.72 52 122.'55 96.4 PO 0.0 96.41 475.56 40.82 54 102.26 96.4 PO 0.0 96.42 475.57 40.86 56 81.97 96.4 PO 0.0 96.42 475.56 40.85 ' 58 61.68 96.4 PO 0.0 96.39 475.55 40.78 60 41.39 96.2 RO 0.0 .96.18 475.53 40.65 62 21.10 95.5 RO 0.0 95.53 475.49 40.47 64 0.81 94.7 RO 0.0 94.67 475.45 40.23 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx**xxxxx***xxxxxxxxxxxx*xxx * ROUT VERSION 5.2 xxxxxxxxxxxxxxxxxxxx*xxxxxxxxxxxx****xxx**xxxxx*xxxxxxxxx*xxx*xxxxxxx**xxx * PROJECT : FOREST LAKES DAM A 10 YR. * DATE : 4-18-88 **x**xxx**xxx**x****xx**xxxxxx*xx*x**xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx STRUCTURE 1 1: TYPE 3: RISER WEIR: 2: ELEVATION (FT) 0.00 3: LENGTH (FT) 0.00 4: COEFFICIENT 0.00 RISER: 5: ELEVATION (FT) 473.00 6: DIAMETER (IN) 48.00 7: ORIFICE ELEVATION (FT) 0.00 8: ORIFICE DIAMETER (IN) 0.00 9: ORIFICE ELEVATION (FT) 0.00 10: ORIFICE DIAMETER (IN) 0.00 11: ORIFICE ELEVATION (FT) 0.00 12: ORIFICE DIAMETER (IN) 0.00 PIPE: 13: INVERT ELEVATION (FT) 458.00 14: DIAMETER (IN) 30.00 15: ORIFICE DIAMETER (IN) 30.00 16: LENGTH (FT) 250.00 17: MANNING'S N 0.013 18: SLOPE (FT/FT) 0.031 19: ENTRANCE LOSS COEFFICIENT 0.50 SURFACE: 20: INITIAL ELEVATION (FT) 473.00 STORAGE POND CHARACTERISTICS: (CALCULATED) SECTION 1 STRUCTURE 2 1: WEIR 477.00 10.00 2.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000 0.000 0.00 ELEVATION (FEET) 459.67 STRUCTURE 3 AREA (ACRE) 0.00 2 462.00 0.70 3 466.00 1.90 4 470.00 3.30 5 474.00 5.00 6 476.00 6.00 7 480.00 8.70 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.000 0.000 0.00 * PROJECT FOREST LAKES DAM A 10 YR. * DATE : 4-18-88 CONTROL: RW = RISER ACTING AS A WEIR RO = RISER ACTING AS AN ORIFICE PI = HORIZONTAL PIPE IN INLET CONTROL PO = HORIZONTAL PIPE IN OUTLET CONTROL TIME INFLOW RISER WEIR TOTAL ELEV STORAGE (MIN) (CFS) (CFS) (CFS) (CFS) (FT) (AC -FT) ------------------------------------------------------------- 0 0.00 0.0 0.0 0.00 473.00 28.16 2 23.12 0.0 RW 0.0 0.03 473.01 28.20 4 46.23 0.2 RW 0.0 0.20 473.03 28.29 6 69.35 0.7 RW 0.0 0.65 473.06 28.44 8 92.47 1.5 RW 0.0 1.50 473.11 28.65 10 115.58 2.9 RW 0.0 2.88 473.17 28.92 12 138.70 4.9 RW 0.0 4.90 473.24 29.25 14 161.82 7.7 RW 0.0 7.66 473.32 29.63 16 184.93 11.2 RW 0.0 11.24 473.42 30.06 18 208.05 15.7 RW 0.0 15.71 473.52 30.55 20 231.17 21.1 RW 0.0 21.14 473.63 31.08 22 254.28 27.6 RW 0.0 27.57 473.76 31.66 24 277.40 35.0 RW 0.0 35.02 473.89 32.29 26 263.56 42.9 RW 0.0 42.88 474.02 32.91 28 249.72 50.4 RW 0.0 50.40 474.13 33.47 30 235.87 57.5 RW 0.0 57.46 474.24 33.98 32 222.03 64.0 RW 0.0 63.97 474.33 34.43 34 208.19 69.9 RW 0.0 69.87 474.41 34.83 36 194.35 73.5 RO 0.0 73.53 474.48 35.18 38 180.50 75.0 RO 0.0 75.01 474.54 35.48 40 166.66 76.3 RO 0.0 76.26 474.59 35.74 42 152.82 77.3 RO 0.0 77.30 474.63 35.96 44 138.98 78.1 RO 0.0 78.15 474.67 36.15 46 125.13 78.8 RO 0.0 78.80 474.70 36.29 48 111.29 79.3 RO 0.0 79.27 474.72 36.39 50 97.45 79.6 RO 0.0 79.57 474.73 36.46 52 83.61 79.7 RO 0.0 79.70 474.74 - 36.49 54 69.77 79.7 RO 0.0 79.67 474.73 36.48 56 55.92 79.5 RO 0.0 79.45 474.72 36.43 58 42.08 79.1 RO 0.0 79.07 474.71 36.35 60 28.24 78.5 RO 0.0 78.50 474.68 36.22 62 14.40 77.8 RO 0.0 77.76 474.65 36.06 64 0.55 76.8 RO 0.0 76.84 474.61 35.87 J. THOMAS GALE, LS. MARILYNN R. GALE LS. WILLIAM S. ROUOABUSH. L5. ,OBJECT ROUDABUSH, GALE & ASSOC., INC. A PROFI-SSIONAL CORPORAT10:1 914 MONTICELLO ROAD CHARLOTTESVILLE. VIRGINIA 22902 FOREST LAKES SOUTH STORM WATER DETENTION FEB.10, 1993 PHONE 1804) 293.4251 IB041 977O205 FAA (604) 296 5220 DAVID L. COLLINS. LS DIANA P. DALE. PE. Determine storm water detention requirements for the current phase of Forest Lakes. CONCLUSION: Due to the surplus detention provided by the four lakes in the first phase of Forest Lakes, the total 10 year peak post -development flow does not exceed that before development, and therefore, further detention for the current phase is not required. FOREST LAKES, PHASE ONE: (see attached calculations by AT&E) Q10 before = 200 cfs Q10 after = 60 cfs FOREST LAKES, SOUTH; CURRENT PHASE: before: 71 ac., C=0.3 , Tc=24 min., i10=4.7 in./hr. Q10before = 77 cfs after: 71 ac. ,C=0.35 Q10after = 99 cfs TOTAL FLOWS: Q10before = 277 cfs 210-after = 159 cfs Tc=20 min., ii0=4.0 in./hr. rj r C _t r ESVILLC gL6EMARLC - 1 9,11 ,Itl UM tl /I (' 'rooter — h{I I1 '( anrd Har'Iv— \ b ( / .aRiv, ..._ _ � � ft\fly On i Gardens \ s n �• . RivaLna J Me m Gardens' aYr bam ^ TPalrkl / ...... �Hollymearr t Gem..! A e Proffil 1; G M,439 11, �r/i / �q es3't _.\ � _ 6 'I it , 4 l ;`_ cP ;I .L .♦me . •• :ACer+y7 �q, oyn� sa `r -_: 6• .. • a la � a a M/ o n, t �<a (' oar �% � ••_ r ./•. i ) Jet �— ��' .Fr �� e8n9bP0ok "�\\ -' Y L _ Z rv,ry cvrri.-s•�i � , 9h = aLh-9is =7/ � cv�w 5'•EI � j S � _ oqZ 6 9iS-�6S c' C„ od 7J -31 — 3 i C" C' l i i 6r� o� I 'FOREST -LAKES DAn S4s 100 yR. FLOOD LEvct•S 1-�6UT icS�L; f•1 E.% ;-� s Z`!•�2� @ kIC,H WAT•�ft la%,j AT 6V I•!ti. kCTii :: `I z1•g k4 .I . y'17. a, 473.0 A I or `f 53.?3 ycy,o 2 So 4 so 4,4),74 3L 6 335 Q= 4b.� cFs Fo Q� $q Ro `IHo,V 44o Q= 78 Pi h=� O v3o,o 3o"d Yf z. 6 Ro r �� BLOCK - C 'AMBERFIELD' SHEETS 10 & It COMMON SPACE' ,SHEET S' BLOCK - B 'COVE POINTE' SHEETS B B B SHEETS M EI] B SHEETS MBI B s BOUNDARY PLAT INDEX TO PLATS SHEET 3 PHASE 1 FOREST LAKES . -ALBEMARLB COUNTY. VIRDBIIA e sL L HnNta a4' a... G h:N W Mf LUDABUSK GALE 6 ASSOC, INC. AYROFYS}N/M L mRq.0 rMx oWr)ar.. rr.. FILE 7015 PHONE F (604) 293-4251 (' Y77-0206 s r ...., ROUDABUSH, GALE IN ASSOC„ INC. D14 MONTICELLO ROAD CHARLOTTESVILLE. VIRGINIA 22901 I JJ f l .5 TO: L�Vtr, �Y,eLutCL COLt n�,, �Y,�{ yu2p�Lc�nC I L(EU M G� UORSHafiGUM /a-i':& Date: 9%aile7 Job No. 7216 Attention: RE: GENTLEMEN: NAND DELIVERED WE ARE SENDING YOU ❑ Attached ❑ Under separate cover via_ ❑ Shop drawings ❑ Prints ❑ Plans L1 Plats ❑Copy of letter ❑ Change order ❑ the following items: [� Specifications OPIES DATE NO. -- - d / �1 C'cG1c'u6aL�<^OCm A THESE ARE TRANSMITTED as checked below: For approval ❑ For your use ❑ Please return ❑4 s requested ❑ Resubmitted with revisions FOR REVIEW AND COMMENT ❑ FOR BIDS DUE 19 ❑ PRINTS RETURNED AFTER LOAN TO US REMARKS: n COPY TO: SIGNED: 1; )c if). IdW Yy_(4 If enclosures are not as noted/ kindly notify us at once. Applied Technology and Engineering, P.C. P.O. Box 6217 Charlottesville, Virginia 22906 (804)977-1498 ►�_u1 1 � TO: Bill Roudabush From: John Greene Re: Forest Lake Detentio nods Date: Sept. 17, 1987 I have reviewed the runoff calculations and the soils report furnished by the County Engineer's Office for Hollymead Pond Number 1. We confirmed the catchment area to be about 940 acres and the calculations appear to be reasonable. The dam has certainly stood the test of time. Charles Echols used the SCS Method recommended for small farm ponds which resulted in a 25 year peak flow of 904 CFS with 3" of runoff and a 24 hour volume of 1793 Acre-feet. We used the Anderson Method as a check, assuming two conditions in the catchment: 1.) rural and 2.) 20% impervious,and got the following results: Rural- Q10 = 470 CFS, @ tc = 2.3 hours or approximately 1.54" of runoff. Rural- Q25 = 704 CFS, @ to = 2.3 hours or approximately 23' of runoff. 20% Imper: Q10 = 1210 CFS, @ tc = 24 min. or approximately 0.68" of runoff. 20% Imper: Q25 = 1720 CFS, @ to = 24 min. or approximately 1" of runoff. Steve Cresswell said he would accept the existing Echols' calculations as the "master drainage study" for that pond and that a maintenance agreement for the pond and dam would be required. He also said existing and future ponds could serve as the stormwater detention facilities. In light of Steve's comments, I recommend that the Developer offer to install the 48" diameter culvert pipe, as calculated by Charles Echols, with an invert approximately 5' above the normal water level (Steve may want flood routing calculations on this to confirm that it satisfies the detention ordinance). It would be nice for the Developer if he could trade this pipe to the Hollymead Owners Association for his share of the maintenance agreement. We will be glad to provide the drainage calculations for the other ponds when the Developer decides which ones he wants and where lie wants them. With the USGS map and the Illustrative Master Plan that you furnished, I believe we have everything we need to perform these calculations. Please let us know how to proceed. \ ••rr•• v',a3ivivyy ano t• neering, P.C. U F ` P. ar Box 6217 1`/ ��,,,,/J Charlottesville, Virginia 22906 Phone: (804) 977-1498 SHEET NO. /,,/ (/, ' OF 7 CALCULATED BY J, "" ' DATE q— Z/ — 9 / CHECKED BY DATE 11 I?SU 1%-71 fVNfZt GULg no" L SCALE ��I 1 _I . LA1 G i l �'T •- pR ,-y � o�F �G�r��wc/1���4_ �, � 61 f .III N/IA/. role Fac O,c/CKlAlnil hied — -- 30 IFS i I + 1 sec : -.. .. --� — —• Mm _ �. (_VPL:, ? _,_. (2.�7� C2,5 IMIM (po — �{&/ �7�, C.F. Q+oo -, V.,00. (ouC-eL13 '�ulZr AG% I+!<cA ,IT STof1t�U RIS%iZ. r- zt/AY+On/ 4=74 To P Pl�ov+uCO I +.8 ►0 3+ qoo C WeLL' OVER- 100 v2 • VO(- 1 `,F. DESl4� RGCAM�ic.N4aT1oN a Dui To Lc.nTu�! riF! LtiKCJ PIR9v(r?C- Lnrcc,� ; RISCIZ, bz lzw(5 -rp pi?,oVrD,e _MORC , CoN!TAN-f wATCre LLVCL- AND PRE,VCn(T .(k+C,la wArcr� A.Y C_LU13- AN!o, oVCFi- P+�CnpoVli:RLG� pA l<r+�y ,. C,)N ,Pi 1OTi"Fl f-), l�u+niMSTiZEd�/: P2DV+o.c 51LT 7.?A' UPS'rIZOW+. I-oIZ- •WP-(GIe QUAi.ITY , . Appima iocnnology and Er eering, P.C. P. 0. Box 6217 Charlottesville, Virginia 22906 Phone: (804) 977-1498 PIR?cu jivAley (2A6Zuc.,071ovS 8HEET NO. CALCULATED CHECKED By OF DATE DATE -Imw- ,A-M:H w9m I Pao 61 log 'd ell C4, rb 14. C, FI-- q _ll c-� I V. 6 5 700 61 0 K 6-.. '—Y tit, wu W"LL W— AY I T p Applied Technology and E, 'neering, P.C. lue P. O. Box 6217 SHEET NO, -3 oF 6E Chadoffesville, Virginia 22906 CALCULATED BY Ij �j 4 - DATE 9-z/-87 Phone: (804) 977-1498 CHECKED BY - DATE 1?6&11"?IN412y CM-C�u-WrfvA/S SCALE - - - - - - - - - - - AT A tipy-T Akeg!�-.= 5 ?4' . . . . . . . . . . 0--- c -11 -3 Wg 4, 1.- 1 q F s -A I a a.:, 0 : K - iT _ _ I _) �ogg s' -1., �tr! �d q 7 I I f I 21 MI" I-! t fi 9 VOL Cie T \1 o L- 1 4 51 C4 00 C, r-, t 30 mat zV pe,) 0 (0 I le 00 0� Ov 33 V, ....,,vyr Una L, IneerIng, P.C. UP. O. Box 6217 Charlottesville, Virginia 22906 Phone: (804) 977-1498 r I SHEET NO. - CALCULATED BY CHECKED BY_ / OF IW U DATE DATE n t.1 t 1 n' o - -� /. . 10,mtit=— '•.,R CIA a•: 1 0 PA 0 ii Ir l WY ✓ii� n ' c f IK Al) F`MER<ER RUB Co. AIRPORT ur r J� �l / l/NI tI.R NaRIrM g / -1. 10, 10, as Ra. >t SS. RYE 649 E[yT. A.r�'C.Y.P. ak,' � � ® - _ sr ,.L l 1. U 0.! ARE rl �333��3331111f1 c.0 lc. y F O.J4t. sIxYMVfG I RRO �Mwl - ' L RE[REBM1Wi FAUL TI o ER VA Pow 43 r FOREST LAKES a MASTER DRAINAGE PLAN Fi a� Sheet 1 of 2 _�,� �f fO La w -ih L_ nn .A r ,A�I �r .r ��\ r,7 l�• ors _•,�Jr. _ lt�� •�//f .'���)� � �'• �S��1J ��"(��1� `t ". ifl Ail r 1 f 1 ' r 57 �� i' 1n`� � .. ♦ /vv \ j), J'� TIME OF CONCENTRATION ARBOR LAKE OVERLAND FLOW TIME UPPER ELEVATION 626 LOWER ELEVATION 624 LENGTH IN FEET 100 SLOPE = 2 % Tc 14 min SHALLOW CONCENTRATED FLOW UPPER ELEVATION 624 LOWER ELEVATION 584 LENGTH IN FEET 556 SLOPE = 7.2 % Tc 2 min CHANNEL FLOW UPPER ELEVATION 584 LOWER ELEVATION 476 HEIGHT IN FEET 108 LENGTH IN FEET 3749 Tc 13 min TOTALTC 29 min 6r )) A^� J%r K C.r\ vkh'rc. A,\0 NfTi• C-FACTOR CALCULATION ARBOR LAKE West of 29/South of Airport Rd EXISTING BUILDINGS EXISTING PARKING/DRIVEWAYS West Worth Crossing/East 29 EXISTING BUILDINGS EXISTING PARKING/DRIVEWAYS West Worth Crossing EXISTING BUILDINGS EXISTING PARKING/DRIVEWAYS EXISTING ROADS EXISTING FOREST SOIL C EXISTING FOREST SOIL B EXISTING OPEN SPACE SOIL C EXISTING OPEN SPACE SOIL B TIMBERWOOD SQUARE ADDED IMP WEIGHTED CN VALUE FT2 C FACTOR AREAS (AC) WEIGHTED C-FACTOR TOTAL AREA = 164.8 AC 122,319 0.9 2.81 2.53 274,440 0.9 6.30 5.67 123,737 0.9 2.84 2.56 366,924 0.9 8.42 7.58 303,598 0.9 6.97 6.27 349,319 0.9 8.02 7.22 657,557 0.9 15.10 13.59 115,870 0.3 2.66 0.80 1,332,065 0.3 30.58 9.17 282,704 0.3 6.49 1.95 3,175,524 0.3 72.90 21.87 73,181 0.9 1.68 1.51 0.49 % IMPERIOUS 31.64 r- Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 31382019 by Autodesk, Inc. v2020 Hyd. No. 7 ARBOR LAKE INLOW 209 Monday, 09 / 2312019 Hydrograph type = Rational Peak discharge = 212.97 cfs Storm frequency = 2 yrs Time to peak = 24 min Time interval = 1 min Hyd. volume = 306,677 cuft Drainage area = 164.800 ac Runoff coeff. = 0.49 Intensity = 2.637 in/hr Tc by User = 24.00 min IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 I i r I Q (Cfs) 240.00 210.00 180.00 150.00 120.00 30.00 ARBOR LAKE INLOW Hyd No. 7 -- 2 Year Q (cfs) 240.00 210.00 180.00 150.00 120.00 30.00 0.00 W I I I I I I I I I I 1 I I 1 I I I I I 1 1 r 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Hyd No. 7 Time (min) 210 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk0 Civil 3DO 2019 by Autodesk, Inc. v2020 Hyd. No. 7 ARBOR LAKE INLOW Monday, 09/23/2019 Hydrograph type = Rational Peak discharge = 284.77 cfs Storm frequency = 10 yrs Time to peak = 24 min Time interval = 1 min Hyd. volume = 410,076 cuft Drainage area = 164.800 ac Runoff coeff. = 0.49 Intensity = 3.527 in/hr Tc by User = 24.00 min IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 ARBOR LAKE INLOW Q (cfs) Hyd No 7 -- 10 Year Q (cfs) 320.00 28000 240.00 200.00 160.00 120.00 80.00 40.00 000 320.00 280.00 240.00 200.00 160.00 120.00 80.00 40.00 000 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Hyd No. 7 Time (min) 211 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Monday, 09 / 23 / 2019 Hyd. No. 7 ARBOR LAKE INLOW r Hydrograph type = Rational Peak discharge = 386.82 cfs Storm frequency = 100 yrs Time to peak = 24 min Time interval = 1 min Hyd. volume = 557,022 cuft r Drainage area = 164.800 ac Runoff coeff. = 0.49 Intensity = 4.790 in/hr Tc by User = 24.00 min IDF Curve = ALBEMARLE IDF.IDF Asc/Rec limb fact = 1/1 Q (Cfs) 420.00 360.00 300.00 240.00 180.00 120.00 60.00 ARBOR LAKE INLOW Hyd. No. 7 — 100 Year Q (cfs) 420.00 360.00 300.00 240.00 180.00 120.00 0.00 V I I I 1 11 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 V 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Hyd No. 7 Time (min) Pond Report r- Hydrallow Hydrographs Extension for AutodeskO Civil 3D® 2019 by Autodesk, Inc. v2020 Monday, 09 / 1612019 Pond No. 20 - Arbor Lake Pond Data Contours -User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 473.24 ft Stage / Storage Table Stage (ft) Elevation (ft) Contour area (scift) Incr. Storage (tuft) Total storage (tuft) 0.00 473.24 199,287 0 0 0.76 474.00 217,800 158,495 158,495 . 2.76 476.00 261,360 479,160 637,655 6,76 480.00 378,972 1,280,664 1,918,319 Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] Rise (in) = 36.00 0.00 0.00 0.00 Crest Len (ft) = 12.57 10.00 Inactive 0.00 Span (in) = 36.00 0.00 0.00 0.00 Crest El. (ft) = 473.24 477.38 0.00 0.00 No. Barrels = 1 0 0 0 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert El. (ft) = 460.19 0.00 0.00 0.00 Weir Type = 1 Rect Rect - Length (ft) = 249.11 0.00 0.00 0.00 Multi -Stage = Yes Yes Yes No Slope I%) = 3.40 0.00 0.00 n/s N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.50 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Contour) Multi -Stage = We No No No TW Elev. (ft) = 0.00 Note: Culm"t Odrs» oudiows are waWnd under inlet(ic) and outlet(w) control. Weir risers checked for odrw contlitions(la) and submergence (a) Stage (ft) Stage I Discharge Elev (ft) 7.00 6.00 5.00 4.00 3.00 t 2.00 1.00 0 00 480.24 479.24 478.24 477.24 476.24 475.24 474.24 47324 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0 90.0 100.0 110.0 120.0 130.0 Total Q Discharge (cfs) 213 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 12 ARBOR LAKE ROUTED Hydrograph type = Reservoir Peak discharge Storm frequency = 2 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 7 -ARBOR LAKE INLOW Max. Elevation Reservoir name = Arbor Lake Max. Storage Storage Indication method used Q (cfs) 240.00 210.00 180.00 150.00 120.00 •M 30.00 ARBOR LAKE ROUTED Hyd. No. 12 -- 2 Year Monday, 09/23/2019 = 49.51 cfs = 42 min = 306,659 cuft = 474.36 ft = 243,983 cuft Q (cfs) 240.00 210.00 180.00 150.00 120.00 cM 0.00 0.00 0 60 120 180 240 300 360 420 480 540 600 660 720 — Hyd No. 12 —Hyd No. 7 iTrFM Total storage used = 243,983 tuft Time (min) 214 Hydrograph Report Hydraflow Hydrographs Extension for Autodesk® Civil 3D® 2019 by Autodesk, Inc. v2020 Hyd. No. 12 ARBOR LAKE ROUTED Hydrograph type = Reservoir Peak discharge Storm frequency = 10 yrs Time to peak Time interval = 1 min Hyd. volume Inflow hyd. No. = 7 -ARBOR LAKE INLOW Max. Elevation Reservoir name = Arbor Lake Max. Storage Storage Indication method used Q (cfs) 320.00 280.00 240.00 160.00 120.00 �1 111 ARBOR LAKE ROUTED Hyd. No. 12 -- 10 Year Monday, 09/23/2019 = 71.79 cfs = 42 min = 410,058 cult = 474.67 ft = 319,295 cuft Q (cfs) 320.00 280.00 240.00 200.00 160.00 120.00 0.00 0.00 0 60 120 180 240 300 360 420 480 540 600 — Hyd No. 12 —Hyd No. 7 Total storage used = 319,295 cult Time (min) Hydrograph Report 216 Hydraflow Hydrographs Extension for Autodesk® Civil 31302019 by Autodesk, Inc. v2020 Monday, 09 / 23 12019 Hyd. No. 12 ARBOR LAKE ROUTED Hydrograph type = Reservoir Peak discharge = 81.15 cfs Storm frequency = 100 yrs Time to peak = 66 min Time interval = 1 min Hyd. volume = 557,004 cuft Inflow hyd. No. = 7 - ARBOR LAKE INLOW Max. Elevation = 475.18 ft Reservoir name = Arbor Lake Max. Storage = 441,663 cuft �-- Storage Indication method used i ARBOR LAKE ROUTED V ■I����������its too