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HomeMy WebLinkAboutWPO201800007 Plan - VSMP 2018-04-16RIVANNA VILLAGE: RIVANNA VIL11-AGE - 1AND PHASE II STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA WPO 201800007/STORMWATER ALBEMARLE COUNTY, VIRGINIA SCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G PROJECT NARRATIVE SHEET INDEX Williamsburg, VA23185 p:757-870-4825 1.) COVER THE PROPOSED STORMWATER PLAN FOR PHASE 2 OF RIVANNA VILLAGE CONSISTS OF THOSE ,,.�� ROHMo 2.) EXISTING CONDITIONS MEASURES NECESSARY TO MANAGE STORMWATER RUNOFF FROM THE PHASE 2 •� ND RO _ RT25p 3.) SHEET INDEX a % DEVELOPMENT (SEE PHASE 2 SITE PLANS SUBMITTED BY ALAN FRANKLIN, P.E.). IN ADDITION, �� 4.) MASTERPLAN THIS PLAN PRESENTS STORMWATER MASTERPLAN CALCULATIONS THAT DEMONSTRATE 5.) STORMWATER PLAN: BLOCK D, F, G COMPLIANCE WITH STORMWATER REGULATIONS FOR THE ENTIRE DEVELOPMENT z' ' - _ 6.) BLOCK G: PROFILE AND SECTIONS INCLUDING THAT WHICH WAS PREVIOUSLY APPROVED FOR PHASE 1 DEVELOPMENT 0' 7J BLOCK G: PLANTING ACTIVITIES CURRENTLY UNDERWAY. % \ '� 8.) STORMWATER PLAN: BLOCK I & BLOCK J ,I �° 9.) BLOCK I & J: PROFILE AND SECTIONS (1) "� SPECIFICALLY, THIS PLAN ADDRESSES: \ \ , 1o.) BLOCK I & J: DESIGN NOTES AND PLANTING (1) -. •\,• � ''° BLOCK I & J: PROFILE AND SECTIONS uJ (z) - PERMANENT STORMWATER CONTROLS WHICH UTILIZE THE PHASE 2 EROSION AND \, 12.) BLOCK I & J: PLANTING (2) " SEDIMENT CONTROL PRACTICE LOCATIONS (WHERE APPLICABLE) AS SHOWN ON THE 1� II7 F �••� \. A \, 13.) STORMWATER PLAN: BLOCK J (EAST & WEST) �q \. PHASE 2 EROSION AND SEDIMENT CONTROL PLANS (INCORPORATED HEREIN BY I\\; 14.) BLOCK J (EAST): PROFILE AND SECTIONS \� \ REFERENCE). THIS PLAN (STAGE 3) DEPICTS PRACTICES TO BE INSTALLED AFTER •� 15.) BLOCK J (EAST & WEST): PLANTING �� COMPLETION OF STAGE 1 AND 2 (AS DEPICTED ON THE EROSION AND SEDIMENT ��`� \. 16.) STORMWATER PLAN: BLOCK J (WEST) CONTROL PLAN) AND AFTER THE SITE IS STABILIZED. \, 17.) BLOCK J (WEST): PROFILE AND SECTIONS 18.) BLOCK (WEST): PLANTING - STORMWATER BMPS DESIGNED IN ACCORDANCE WITH STATE STANDARDS `\ \ 19.) STORMWATER DETAILS �� \ USING THE VIRGINIA RUNOFF REDUCTION METHODOLOGY �. VA q, 20J STORMWATER NOTES `` \ °tiM STORMWATER CONSTRUCTION SEQUENCE (SEE ATTACHED STORMWATER CALCULATIONS) AND MEETING ENERGY BALANCE \\ 21.) `' IN o�O90 PLANTING NOTES AND DETAILS REQUIREMENTS AT THE PROJECT OUTFALL. ,. \ i 22.) �� / �s 23.) PRE -DEVELOPMENT HYDROLOGY y THE PLAN IS DESIGNED TO ALLOW FOR INSTALLATION OF PROPOSED LINEAR i� �! '. `•� � ,� � \ 24.) POST DEVELOPMENT HYDROLOGY KEY PLAN \ INFRASTRUCTURE AND ROADWAYS AND SPECIFIES MEASURES THAT WILL MANAGE RUNOFF 2 � . ,� / �� � �` �: � / ,\ \ ; .,\ 5•) STORMWATER EASEMENTS FROM DEVELOPED AREAS. PROPOSED STORMWATER PRACTICES INCLUDE: r ,� ` % .j `;, �` �` - ENVIRONMENTAL SITE DESIGN PRACTICES (ESD) AND LOW IMPACT DEVELOPMENT 1 f, \� / ; •,, ` (LID) PRACTICES SUCH AS UPLAND BMPS INCLUDING BIORETENTION CELLS AND l , �• I�, �5,. j \��� ✓� �. SITE DATA \ ASSOCIATED SWALES. •! PROJECT LIMITS ACRES (SITE) = 9o.6 - WET SWALES DESIGNED ACCORDING TO STATE STANDARDS AND LOCATED IN CLOSE, .° �� ,'�"/ ,\ % ,-' PHASE i PROJECT LIMITS = 32.3 ACRES /-,�/ PROXIMITY TO EXISTING WETLAND FEATURES IN A SIMILAR TOPOGRAPHIC POSITION. \ EAST RIVANNA ; / \. J ' / `• PHASE 2 PROJECT LIMITS = 68.5 ACRES VOLUNTEER \\� FIRE COMPANY - A LEVEL 2 WET POND DESIGNED TO TREAT SELECT AREAS OF THE PREVIOUSLY /'��P� ) C �� \. (INCLUDES 10.2 ACRES OF DISTURBED PHASE 1) ri APPROVED PHASE 1 DEVELOPMENT, AND PROPOSED PHASE 2 DEVELOPMENT AREAS. PHASE 2 AREAS CONSIST GENERALLY OF THOSE LOCATED ON THE EASTERN PORTION OF THE �° `� °� " �� _ / \F�//� ' I :� " OWNER DEVELOPER SITE, THE PROPOSED PARK, ATHLETIC FIELDS, AND A PORTION OF PROPOSED �.., ._ DEVELOPMENT IN THE SOUTH WEST CORNER OF THE SITE (I.E. BLOCK J WEST). TRAFFIC �/ \`- r�� J ' ! ISSUE a RIVANNA INVESTMENT HOLDINGS LLC MANAGEMENT PRACTICES ARE PROPOSED UNDER SEPARATE COVER AND SHALL BE Illtlld \ ./ (�' t H '� IMPLEMENTED IN COORDINATION WITH THE ACCESS MEASURES PROPOSED HEREIN. �•� \ /fir• / C/O ROBINSON DEVELOPMENT GROUP INC. �� U REV # DATE DESCRIPTION ./ 150 W. MAIN STREET, SUITE 1100 AS DISTURBANCE IS PROPOSED IN THE STREAM BUFFER, THE PROPOSED MITIGATION PLAN a Ii > /ram _ �� .,i "-' • o NORFOLK VA 23510 1 03.02.2018 PER COUNTY COMMENTS. (SUBMITTED UNDER SEPARATE COVER) DETAILS MEASURES NECESSARY (I.E. STREAM /` �Iu ; / RESTORATION) TO MITIGATE FOR THE BUFFER IMPACT. ROVED EXISTING 1 O0' STREAM BUFFER .°° }90 PREVIOUSLY APP. N �� PHi BOUNDARY R W PHASE 1 PROJECT AREA (LIMITS OF DISTURBANCE) = 32.27ACRES t M° SURVEY AND BASE INFORMATION PHASE 2 PROJECT AREA (LIMITS OF DISTURBANCE) = 68.5 ACRES f*� / . ,: ` a ��•� 30 \ ^ *SINCE 10.2 ACRES OF DISTURBANCE WAS PREVIOUSLY PERMITTED WITH PHASE 1 PLANS. " � �\ � � � � / •t ROUDABUSH, GALE &ASSOCIATES, INC. ' i 914 MONTICELLO ROAD VICINITY MAP: 1" = l000' '� \ -+�� N CHARLOTTESVILLE, VIRGINIA 22902 .�\ v _- _ „t t �\�w\` \�'• ••/ \ PHONE: (434) 976-0205 jI/s 4 `�l � '� � � �'` •�• '\ _ . � � • BOUNDARY SURVEY: ROUDABUSH, GALE &ASSOCIATES (434) 977-0205 � TOPOGRAPHIC SURVEY: LOUISA AERIAL SURVEYS, 20o8 (540) 967-1499 • o o �� s FIELD VERIFIED BY ROUDABUSH, GALE & ASSOCIATES IN 2014. 7.• .` , \� �,� • �. SCALE: 1 INCH = 25o FEET - '• � PERMIT INFORMATION APPROVED _ \��� ha I • PROJECT LIMITS O • • • ' C 0 250 500 1,000 r • 1.) PREVIOUSLY APPROVED UNDER 12-SPGP-o1 • �����. �fCONTOUR INTERVAL = 2 FT . RE UNDER by the Albemarle County Dommunity5/9o2 eng Department File WP0201800007 4 z.) -VERIFIED 17-SPGP-o1. ; • . ` 1 �� 41 . �• 0 ` �� 3.) PERMIT APPROVED AS JPA #WP4-13-1230. `�� • • ` i 4.) ALL ASSOCIATED MITIGATION CREDITS PREVIOUSLY PURCHASED • Q ' . ` �I ~ •' �� ' PtiTH OF Gf �. • a•:_! . 0� �� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. +. I �•" � SCOTT C. BLOSSOM y `` �� Lic. No. 40287 COVER 47 0,y �sv �SSIONAL�ti o �\ J 3 ° ��+ : ••�r�� DATE:12/4/2017 SWM - 1 REVISED 3/2/2018 .000, 1 / 62B (C) / v 1 / QQPP J' y4P / 518 (C/D) r / c . M •. ` 51 • TMP 79-25A RIVANNA VILLAGE LLC 1� SITE BENCHMARK 6M 3008 ' VDOTMONUMENT ELEVATION = 419.195 FT NAVD88 / 51 C (C/D) I �� SURVEYED MARCH 2O15 BY ` \ / ROUDABUSH, GALE AND \�_~ ASSOCIATES .0000 628 (C) i I RICHMOND ���•••• TIME 79-D-8 RO (R .B) 2I I ]� RESIDENTIAL ` 0 ' 62B (C) / •/ - TIME 79-D-9 ` I • RESIDENTIAL I 'r 390 TMP 79-D-10 TMP 79-D-11 I dy 3B0 J60 1 / r`r TMP 79-D-19 I ° I ` r+` RESIDENTIAL RESIDENTIAL RESIDENTIAL r`r ` • ` / r�rr TMP ♦ �r ` / RESIDENTIAL I \` TMP 79-D-1 ] RESIDENTIAL / TMP _V 79-D-12 ('1_On_ 1 1{ F rr� RESIDENTIAL ' o �. ♦ 354 / v TMP 79-25C f � DANIS WILLIAMS RESIDENTIAL r ♦�� �r-35C .�r�_� 00, SOILS SUMMARY TABLES WATER TABLE MAP HYDROLOGIC SURFACE KSAT UNIT SOIL NAME SLOPE SOIL GROUP RUNOFF (IN/HR) UPPER LOWER LIMIT LIMIT ABELL SILT 0.57 - 1 B 2- 7% B MEDIUM 2.0-3.5 >6.0 LOAM 1.98 46B 2 - 7 % C HIGH 1 1 .00- SILT .0-2.5 .B-3.0 06 MANTEO 5 CHANNERY 2 - 7 % C/D LOW — — 1 98 98 5.95 SILT LOAM MANTEO 51 C CHANNERY 7 - 15 % C/D LOW — — 1 98 98 5.95 SILT LOAM AON 0.. 62B SLUT SOAM 2 - 7 % C MEDIUM — — 98 W WATER — — — — — — SOIL SURVEY GEOGRAPHIC (SSURGO) DATABASE FOR ALBEMARLE COUNTY, VA SOURCE: U.S. DEPARTMENT OF AGRICULTURE, NATURAL RESOURCE CONSERVATION SERVICE <(qGF< C <C TMP 80-55D DARRELL ULLERY RESIDENTIAL r m `♦♦ JB0 ■ i �♦ J � I TMP 80-51 �( RIVANNA VILLAGE LLC ` \ TIME 80- RESIDENTIAL 518 (C/D) `y�L TMP 80-52 RIVANNA VILLAGE LLC TMP 80-54 POND , Q CHARLES GRADY o ? RESIDENTIAL (C/D) TMP 80-55C / TIMOTHY U. MILTON • / RESIDENTIAL TMP 80-55 / , G RRALDENT ALES / ;..i 1 / TMP TODD COSGROOSGROVE RESIDENTIAL TMP 8049A WILLIAM RESIDENTIALNTIAL / 1 (h ( I \ I � 111 � ��� � // \ � � ) / ��.•��• SEE CIVIL SITE PLANS FOR \\� '�/ � ( �♦ ADDITIONAL BENCHMARK \'fie\`_/// \ �.• �..�' AND SURVEY INFORMATION ♦` TMP80-47 / / TMP 79-26 1�•r BETTY MCCLANLANAHAN DRESID RIGGIN 51 B (�.`/D) RESIDENTIAL TIME 93A4-EIGHB RH9 RESIDENTIAL / ,PIEDMONT NEIGHBORHOODS LP ' / I J�QE o/ v/ 51C (C/D) 51B (C/D)/ \46B (C) I / 1 1 00000 '00,� l^ 01 SCALE: 1 INCH = 20o FEET 0' 200' 400' 800' CONTOUR INTERVAL = 2 FT EXISTING CONDITIONS NARRATIVE AND NOTES THE PROPOSED RIVANNA VILLAGE DEVELOPMENT ENCOMPASSES AN AREA OF FOREST AND OPEN MEADOW LOCATED APPROXIMATELY 12.5 MILES SOUTHEAST OF CHARLOTTESVILLE VIRGINIA. THE SITE IS CHARACTERIZED BY MODERATE SLOPES AND WOODED CORRIDORS THAT WILL BE PRESERVED AS A COMPONENT OF THIS PLAN. TWO (2) EXISTING PONDS ARE LOCATED NEAR THE CONFLUENCE OF THE EXISTING INTERMITTENT STREAM CHANNELS. EXISTING WATER FEATURES INCLUDE 1.o8 ACRES OF WETLANDS AND 2,645 LINEAR FEET OF STREAM CHANNELS THAT DRAIN TO THE RIVANNA RIVER LOCATED APPROXIMATELY 4 MILES DOWNSTREAM. THE PHASE 2 RIVANNA VILLAGE PROJECT LIMITS COVER 68.5 ACRES, FOR A TOTAL PROJECT/SITE AREA OF 90.6 ACRES. GLENMORE WAY AND PIPER WAY SERVE AS THE ENTRANCE ACCESS TO THE ADJACENT NEIGHBORHOODS. AS A COMPONENT OF PHASE 1, STEAMER DRIVE WAS APPROVED AS AN ACCESS ROUTE AND IS CURRENTLY IN USE. THE PHASE 2 PLANS PROPOSE THE CONTINUED USE OF STEAMER DRIVE AND THE ADDITION OF A TURN OFF FROM EXISTING ROUTE 250. ALL EXISTING STRUCTURES WITHIN THE PHASE 2 LIMITS OF DISTURBANCE (SEE CIVIL SITE PLANS) SHALL BE DEMOLISHED AS A COMPONENT OF STAGE 1 CONSTRUCTION ACTIVITIES AS SHOWN ON THE EROSION AND SEDIMENT CONTROL PLAN. THE RIVANNA VILLAGE SITE IS NOT LOCATED WITHIN A FEMA FLOODPLAIN. HYDROLOGIC AND HYDRAULIC ANALYSIS WAS COMPLETED IN CONJUNCTION WITH PRE AND POST DEVELOPMENT SITE ANALYSIS TO VERIFY NO ADVERSE IMPACT TO THE DOWNSTREAM FLOODPLAIN ASSOCIATED WITH DEVELOPMENT ACTIVITIES. LEGEND PREVIOUSLY APPROVED PHASE 1 LIMITS OF DISTURBANCE PROPOSED PHASE 2 LIMITS � OF DISTURBANCE OSITE BENCHMARK (PER ROUDABUSH, GALE AND ASSOC. SURVEY) y°a EXISTING WETLANDS (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING STREAM CHANNEL LIMITS (PER KIRK HUGHES & ASSOC. SURVEY) ©EXISTING POND (PER KIRK HUGHES & ASSOC. SURVEY) APPROXIMATE EXISTING TREE LINE (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING ROAD � (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING FENCE (PER KIRK HUGHES & ASSOC. SURVEY) ®EXISTING BUILDING (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING POWER POLE o. (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING SIGN as (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING MANHOLE H' (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING CONTOURS � (PER KIRK HUGHES & ASSOC. SURVEY) 0 EXISTING STREAM BUFFER (PER ALBEMARLE COUNTY) APPROXIMATE SOIL 56(B) BOUNDARIES EXISTING HYDRIC SOIL (MANTEO CHANNERY SILT LOAM) O E (GREATER S (GREATER (GRTHAN 25%) RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive Williamsburg VA 23185 p:757-870-4825 ISSUE IREV # I DATE I DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. o��PLTH OF Dr.6f x v SCOTT C. BLOSSOM y Lac. No. 40287 ��SSIONAL E0�A Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. EXISTING CONDITIONS SWM - 2 FILEPATH:C:\Users\HiIBDropbox\Projects\005 RivannaNENADesign and Analysis\CAD=5_RivannaPH2_SWM_ REV2.dvglHilllApr 11, 2018 at 17:161Layoul: 2 Ex Conditions LEGEND RIVANNA VILLAGE: �••�„ PROPOSED LIMITS OF DISTURBANCE STORMWATER PLAN „�.•1 l . J BLOCK LIMITS AMENDMENT 1 AND PHASE II `"." �� ALBEMARLE COUNTY, VIRGINIA / 13 LOCK D F AND G SEE SHEETS 5 - 7 J�. �' O EXISTING WETLANDS PER HUGHES &ASSOC. / �•! W�.�W W `!`!° ��KIRK SURVEY) - BLOCK I (SEE SHEETS 8 12) � �� _- � I �.,\ ��\ \ O APPROXIMATE EXISTING STREAM CHANNEL LIMITS (PER KIRK HUGHES & ASSOC. \\\ I I \ SURVEY) An '+ + O �O \ BLOCK B ` `� I I �\ I EXISTING STREAM BUFFER yJ r• • •` ! \ \W I \ is Y� I I I �. �•. �\ +•. I I �,\� • APPROXIMATE EXISTING TREE LINE (PER KIRK HUGHES & ASSOC. .�� �'� �•. � ♦ _ �"� �� �!'�•. I I !I! 6 �. O. , � I SURVEIL EXISTING ROAD BCE N � �•.�.�� �•.�i . .. ```��� I ,�+ • / PROPOSED BRIDGE \ \ • PROPOSED CULVERT : I`\\� ��.� i (SEE CIVIL SITE PLANS FOR ` ,'•�� �� (SEE CIVIL SITE PLANS FOR (• \ '\\ !.` DESIGN DETAILS) I I (PER KIRK HUGHES & ASSOC. SURVEY) EXIST NG FENCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 \ \\ qp'•.� ` �\\ !. DESIGN DETAILS) ; I �'1 ���\ \ I !.`. \ I \ T \ I ♦ I \ (PER KIRK HUGHES &ASSOC. SURVEY) p: 757-870 4825 BLOCK E �'�� ���,, � �•.� �� 0��� �� A. �/ ��\ /;��3e,,a� � v /,Q ExISTINGEUILDING I / ��� \ •. a Y!� �j7 4\ \ (PER KIRK HUGHES &ASSOC. ��� I ��vI — �-+.� — I— �LL�II�� �� — — ��/�/� — — — — — — — — ✓ SURVEIL I!i� S�i,� �BLOCK C BLOCK G . I I c s+ c ��� -�,�� ��•• I I ��ti // '\ w =� I- BLOCK I ► ^�♦ �,• I A 'o --\— —��� — — — — = rt = — — — — ,%• °7-' BLOCK F'r, ���. O, ��v`. �N j O O � � '� •� I BLOCK D � I � v � p � .�� o♦y' I '� s �� P°� ��. ��/ A � \ �.� ,ir �i V• — I I x90 A 360 KEY PLAN - •� — BLOCK A� I � � \ � �•'� BLOCKH � � � i II � � °�.�, �„�rl� � ''— — — — — Zi —I _ J ♦• t / a PROPOSED BRIDGE • ♦+ I �' ISSUE �6 _� I : �° 1• (SEE CIVIL SITE PLANS FOR p DESIGN [DETAILS) PROPOSED CULVERT • \�� I ` / W , . (SEE CIVIL SITE PLANS FOR REV # DATE DESCRIPTION DESIGN DETAILS) I 3 I aoo PREVIOUSLY APPROVED I 1 03.02.2018 PER COUNTY COMMENTS. 390 PHI BOUNDARY N( I O / I\ BLOCK (EAST) BLOCK J (WEST) _ l PROPOSED CULVERT t 360 Y• ♦ ♦ ♦ ♦ ♦ ���� (SEE CIVIL SITE PLANS FOR♦♦.�••in • y !l�WY♦♦ .!.♦! J .. �..�' DESIGN DETAILS) + .• • • / • �36 r . . W W♦.y \ !' y �OUTFALL \ I P1 TH OF D r \ 3so BLOCK I AND J(EAST) (SEE SHEETS 12 - 16) SCOTT C. BLOSSOM y Lac. No. 40287 04� �w ION BLOCK H AND J(WEST) (SEE SHEETS 1 . - 201 I \. \\ N Job No: 1005 1 Drawn By: BCE Date: 12.04.2017 1 Checked By: Scott C. Blossom. P.E. y \ SH EET I N D EX SCALE: I INCH = 15o FEET CONTOUR INTERVAL = 2 FT 111111111 3 SWM FILEPATH:C:\Users\HilhDropboz\Prgecls\005 RivannaNENADesign and Analysis\CAD\005_RivannaPH2_SWM_REV2.tivgHillApr 11, 2078 al 17:i6Layoul: 3 Intlez Sheet VIRGINIA RUNOFF REDUCTION METHOD (WATER QUALITY) CALCULATIONS Land Cover (acres) A Soils B Soils C Soils D Soils Totals Forest/Open Space (acres) -- undisturbed, protected forest/open space or reforested 22.34 22.34 Managed Turf (acres) -- disturbed, graded foryards or otherturf to be 36.26 36.26 Impervious Cover (acres) 32.01 32.01 * Forest/Open Space areas must beprotected in accordance with the Virginia Runoff Reduction Method 90.61 Forest/Open Space Cover (acres) 22.34 Treatment Volume 32733 (acre-ft) Treatment Volume (cubic feet) 142,586 TP Load (lb/yr) 89.59 TN Load (I b/yr) 64089 Informational Purposes Onlyl Post -Development R- ,for Site Area TP Load Reduction Required (lb/yr) 52.44 Weighted Rv (forest) 0.04 %Forest 25% Managed Turf Cover (acres) 36.26 Weighted Rv (turf) 0.22 % Managed Turf 40% Impervious Cover (acres) 32.01 Rv (impervious) 0.95 %Impervious 35% Site Area (acres) 90.61 Site Rv 0.43 REMOVAL REQUIRED BY VRRM (SEE CORRESPONDING VRRM SPREADSHEETS) RIVANNA VILLAGE OVERALL WATER QUALITY COMPLIANCE PROPOSED CONDITIONS FINAL CREDIT PHASE PROPOSED FACILITY ID BMP Type (per VSWMH) Drainage Area (acres) TP Removal Efficiency(%) IIB Prop Loading (Ib TP/yr) TP Load Removed, Direct Drainage (Ib TP/yr) Remaining Phosphours Load (Ib TP/yr) TP Load Removed, Direct Drainage (Ib TP/yr) 1 AS3a-1 BIORETENTION FILTER(L1) 1.68 55 1.88 1.03 0.85 1.03 1 A53a-2 BIORETENTION FILTER(Ll) 2.8 55 3.07 1.69 1.39 1.68 1 A53a-3 BIORETENTION FILTER(L1) 1.68 55 2.13 1.17 0.96 1.17 1 AS31b DRY SWALE Ll.... in series 0.67 52 0.57 0.30 0.13 0.44 1 AS3c WET SWALE (LI) ... 1 n series 1.22 1 20 0.99 0.20 1 0.36 0.63 1 AS3d I BIORETENTION FILTER (Ll)... i n series 2.16 55 1.62 0.89 0.36 1.26 1 BS3a jailD RETENTION FILTER (L2)... I nseries 1.6 90 2.05 1.95 0.17 1.88 1 BS3b IBIORETENTION FILTER(L2) 1.96 90 2.41 2.17 0.24 2.17 1 ES3 IBIORETENTION FILTER(L1) 1.92 55 1.92 1.06 0.86 1.06 1 HS3a BIORETENTION FILTER(L2) 2.84 90 3.51 3.16 0.36 3.15 2 G1 BIORETENTION FILTER(L2) 2010 90 2.82 2.54 0.28 2.54 2 G2 BIORETENTION FILTER(L2) 0.409 90 0.47 0.42 0.05 0.42 2 G3 BIORETENTION FILTER(L2) 0.958 90 1.26 1.13 0.13 1.13 2 H1 BIORETENTION FILTER(L2) 0.990 90 1.19 1.07 0.12 1.07 2 I2/I3 BIORETENTION FILTER(L2) 3.89 1 90 3.95 3.56 1 0.40 3.56 2 J1 WET SWALE(L2) 2.82 40 3.51 1.40 2.11 1.40 2 J2 WET SWALE(L2) 2.587 40 3.39 1.36 2.03 1.36 2 J3 BIORETENTION FILTER(L1) 0.87 55 1.12 0.62 0.50 0.62 2 J5 BIORETENTION FILTER 1-1) 1.39 55 2 1.10 0.90 1.10 2 J6 SIMPLE DISCONNECTION 0.57 25 0.49 0.12 0.37 0.12 2 J7 GRASSED SWALE(C/D) 0.73 23.5 0.72 0.17 0.55 0.17 1&2 11 WET POND (L2)..... direct 34.14 65 36.73 23.87 12.86 23.87 1&2 1 11 WETPOND(L2)..... in series 8.857 1 65 10.93 9.21 1 1.73 1.12 TOTAL PROPOSED REMOVAL Ibs TP/yr): 52.95 OVERALL SITE REQUIRED REMOVAL (Ibs TP/yr): 52.44 OVER/ UNDER Treatment (Ibs TP/yr): 0.51 REQUIRED OFFSITE COMPLIANCE (Ibs TP/yr): 0.00 *The water quality benefit of the proposed land conversion BMPs was applied through adjusting the land cover conditions for the site 1 nherent in the VRRM calculations. TREATMENT VOLUME REQUIRED BY VRRM PHASE PROPOSED FACILITY ID BMP Type (per VSWMH) Required Treatment Volume (cf) Surface Area (sf) Effective Depth (ft) Provided Treatment Volume(d) Provided Tv > Required Tv? 1 AS3a-1 BIORETENTION FILTER (Ll) 3,041 1,576 1.4 2,206 1 AS3a-2 BIORETENTION FILTER (Ll) 4,958 4,030 1.4 5,642 YES 1 AS3a-3 BIORETENTION FILTER (L1) 3,410 2,572 1.4 3,601 1 AS31O DRY SWALE(L1).... inseries 900 900 1 1,260 YES 1 AS3c WET SWALE(Ll)... inseries 1,610 1,920 1.00 1,920 YES 1 AS3d BIORETENTION FILTER (L1)... inseries 2,685 2,538 1.40 3,553 YES 1 BS3a BIORETENTION FILTER (L2)... inseries 4,094 3,559 1.65 5,872 YES 1 BS3b BIORETENTION FILTER (1-2) 4,839 2,708 1.65 4,467 NO 1 ES3 BIORETENTION FILTER (1-1) 3,068 3,425 1.40 4,795 YES 1 HS3a BIORETENTION FILTER (L2) 6,979 3,849 1.65 6,351 NO 2 G1 BIORETENTION FILTER (L2) 5,625 4,001 1.65 6,602 YES 2 G2 BIORETENTION FILTER (L2) 928 1,589 1.65 2,622 YES 2 G3 BIORETENTION FILTER (L2) 2,500 2,669 1.65 1 4,404 YES 2 H1 BIORETENTION FILTER (L2) 2,364 2,225 1.65 3,671 YES 2 I2/I3 BIORETENTION FILTER (L2) 7,878 5,113 1.65 8,436 YES 2 11 WET SWALE(12) 7,786 12,386 n/a 20,015 YES 2 J2 WET SWALE(12) 8,669 8,744 n/a 14,458 YES 2 J3 BIORETENTION FILTER (L1) 1,786 2,102 1.40 2,943 YES 2 J5 BIORETENTIONFILTER (Ll) 3,180 2,378 1.40 3,330 YES 2 J6 SIMPLE DISCONNECTION 779 2,750 1 0.4 1,100 YES 2 J7 GRASSED SWALE (C/D) 1,139 960 0.5 480 NO 1&2 11 WET POND (L2)..... onsite 114,272 75,716 235,469 YES 1 & 2 11 WET POND (L2)..... offsite (turflimp) 96,936 11 WETPOND(L2)..... total 211,208 'NOT REQUIRED BUT PROVIDED BECAUSE THE POND MUST BE SIZED TO ATTAIN QUANTITY COMPLIANCE (SEE BELOW) PHASE II WET POND (11) DRAINAGE AREA = 97.0 ACRES REMOVAL PROVIDED INCLUDES 30.81 LBS/YR (0.51 LBS TREATS PORTION OF PHASE 1 AND PHASE 2 DEVELOPMENT TP ON -SITE, 30.3 LEIS TP OFF -SITE) ABOVE REMOVAL TP REMOVAL (ONSITE AREA) = 24.99 LBS/YR REQUIRED (INCLUDING TREATMENT OF OFFSITE TP REMOVAL (OFFSITE AREA) = 30.30 LBS/YR AREAS). OWNER MAY PURSUE NUTRIENT BANKING (ALL TURF & IMPERVIOUS) UNDER SEPARATE COVER UPON APPROVAL. ENERGY BALANCE SUMMARY (WATER QUANTITY) ENERGY BALANCE Rvpre= 1 6.28 RVpost= 1 9.85 Rvpre/Rvpost 1 0.64 q allowable= I LF.'(Q,ac'RV,Ia,VRV.Ev allowable= 1 46.92 ch Ig post routed 34.17 ch alloable/ in to WP= 0.35 take ratio to table Vs r =w 0.349 vs 1 3.44 ac-ft stora gore ui red Vs(provided) 3.50lac-ftb/w NP and Top of Riser' THIS IS LOOKING AT CHANNEL ADEQUACYATTHE POND OUIFALL. Drainage Area to the Pond = 97.7 acres (includes o0site a rea) 'Includes 5toa rge in Upland BMPs FNFRr.V RAI ANCF Rvpre= I 13A0 Rvpost= 1 17.41 Rvpre/Rvpost 1 0.77 q allowable- ILF.'(Q,ac'RV,ad/RVow Ig allowable= 159 ch post routed 10213.J1 ch allowable/ in to WP= 0.46 take ratio to table Vs r = 0393 Vs= 5.10 ac-ft storage ruired Vs rovldetl 7.05 ac-ftb WNP and To of Riser' THIS 15 LOOKING AT CHANNELADEQUACY ATTHE PROJECT OI UTALL. 'Includes Stoarge in Upland BMPs SCALE: 1 INCH = 2oo FEET M CONTOUR INTERVAL = 2 FT ,Is�'� RIVANNA VILLAGE: "" -1 f .STORMWATER PLAN ,, ' AMENDMENT 1 AND PHASE II so ALBEMARLE COUNTY, VIRGINIA I PHASE II WET POND (11) DRAINAGE AREA = 97.7 ACRES a TREATS PHASE 1 DEVELOPMENT AND PHASE 2 DEVELOPMENT TP REMOVAL (ONSITE AREA) = 38.59 LBSNR - TP REMOVAL (OFFSITE AREA) = 30.03 LBSNR (OFFSITE AREA CALCULATED AS TURF & IMPERVIOUS) [LE G3 - RETENTION = 4.09 LBS/YR No RD BICE • •,~ , Blossom Consulting and Engineering Inc. BS3b V / LEVEL 2 BIORETENTION 1101 Professional Drive, Suite G Williamsburg, VA 23185 L �•� •��� BPS = 2.17 LBSNR a p757-870-4825 �nl�� �. •`�'� I BS3a -� r� �, '�• LEVEL 2 BIORETENTION ' P REMOVAL = 1.88 LBSNR I I ,/1 A- C is 51 yh( �-.. •�� 12 AND 13 ES3tl a •� , I r\rrl A nI( MrrT!-n ITI( NIO Tn nrn e(\n, n cn_ , nn non 13:yd,I_1ki ISSUE IREV # I DATE I DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. H OF Dr�� � z v SCOTT C. BLOSSOM y Lac. No. 40287 A �4� ��SSIONAL ����� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER MASTERPLAN CONCLUSION: THE STORMWATER MANAGEMENT MASTERPLAN IS DESIGNED TO MEET ENERGY BALANCE REQUIREMENTS (I.E. Q POST < Q ALLOWABLE, AND VS PROVIDED > VS 3EQUIRED) AT THE TRIBUTARY, POND AND PROJECT OUTFALLS IN CONSIDERATION OF BOTF DHASE 1 AND PHASE 2 DEVELOPMENT. SWM - 4 I 1�1 LEGEND RIVANNA VILLAGE: PROPOSED LIMITS STORMWATER PLAN 'I' 1♦ ♦ \., / \\ \ \ \ . ,o71gR / / / \ \ o OF DISTURBANCE 0 \ \ \ ♦♦ �\ose PREVIOUSLY APPROVED PHASE I BMP I \ 0 ♦♦ / O SITE BENCHMARK (PER RO � ♦♦ \ \\ \\ / ALL ONSITE FOREST PRESERVATION AREAS REFLECTED qc ° � (PER ROUDABUSH, GALE AND AMENDMENT 1 AND PHASE II ♦O `I' ,36/ /� \ IN VRRM CALCULATIONS TO BE COVERED WITH O ° R s ASSOC. SURVEY) RESTRICTIVE CONVENANTS PREVENTING CLEARING AND \ a q q ALBEMARLE COUNTY, VIRGINIA LIMITING MAIANTENANCE ACTIVITIES AS REQUIRED BY �� m+.� EXISTING WETLANDS STORMWATER MANAGEMENT REGULATIONS. wyW�r�.' (PER KIRK HUGHES & ASSOC. • \ \ \ ` / °B O°O�O'Py O / / EXISTING STREAM CHANNEL LIMITS (PER KIRK HUGHES & ASSOC. O O \ SURVEY) II II I F ♦`♦♦♦� ♦ ♦ \ \ \ / �1 \\ \ \ / \ EXISTING POND =mumL l (PEqTTR ` I HUGHES & ASSOC.4* 441 STORMWATER MANAGEMENT CALCULATIONS LEVEL 2 BIORETENTION G1 CALCULATIONS: RUNOFF REDUCTION TREATMENT VOLUME = 4,500 CU.FT. EFFECTIVE STORAGE DEPTH = 1.65 FT REQUIRED SURFACE AREA = 1.25 TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 3,409 SQ.FT. LEVEL 2 BIORETENTION G1 DIMENSIONS: PROPOSED SURFACE AREA = 4,001 SQ.FT., ELEVATION 352 FT SOIL MEDIA DEPTH = 3 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 36 INCHES, RIM ELEVATION = 353 FT OUTLET BARREL LENGTH = 48 FT OUTLET BARREL DIAMETER = 18 INCHES US INV. ELEVATION = 348.0 FT, IDS INV. ELEVATION = 346.0 FT WATER QUALITY ORIFICE DIAMETER = 3.5 INCHES, ELEVATION = 352.5 FT UNDERDRAIN DIAMETER = 5INCHES, INVERT ELEVATION = 348.5 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 4 FT, ELEVATION = 356 FT MINIMUM EMBANKMENT TOP WIDTH = 12 FT MINIMUM SIDE SLOPE = 3:1 (INNER) 3:1 (DOWNSLOPE) AUXILIARY SPILLWAY WIDTH = 10 FEET, ELEVATION = 354.0 FT OUTLET PROTECTION: GIVEN: 18-INCH PIPE OUTFALL 10-YR DISCHARGE (Q) = 11.34 CFS OUTFALLS TO OUTLET PROTECTION AT ELEVATION 346.0 FT A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 2 BIORETENTION G1 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 5INCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 10 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 11 .5 FT LEVEL 2 BIORETENTION G2 CALCULATIONS: RUNOFF REDUCTION TREATMENT VOLUME = 742 CU.FT. EFFECTIVE STORAGE DEPTH = 1.65 FT REQUIRED SURFACE AREA = 1.25 TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 562 SQ.FT. LEVEL 2 BIORETENTION G2 DIMENSIONS: PROPOSED SURFACE AREA = 1,589 SOFT., ELEVATION 355 FT SOIL MEDIA DEPTH = 3 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 36 INCHES, ELEVATION = 356.5 FT OUTLET BARREL LENGTH = 32 FT OUTLET BARREL DIAMETER = 18 INCHES US INV. ELEVATION = 352.5 FT, IDS INV. ELEVATION = 352.0 FT UNDERDRAIN DIAMETER = 5INCHES, INVERT ELEVATION = 352.5 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 2 FT, ELEVATION = 358 FT MINIMUM EMBANKMENT TOP WIDTH = 5 FT MINIMUM SIDE SLOPE = 31 AUXILIARY SPILLWAY WIDTH = 15 FEET, ELEVATION = 357.0 FT OUTLET PROTECTION: GIVEN: 10-YR DISCHARGE (Q) = 2.22 CFS OUTFALLS TO RIPRAP OUTLET PROTECTION A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 2 BIORETENTION G2 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 6INCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 5 FT TRANSITION TO DOWNSTREAM CHANNEL LEVEL 2 BIORETENTION G3 CALCULATIONS: RUNOFF REDUCTION TREATMENT VOLUME = 2,000 CU.FT. EFFECTIVE STORAGE DEPTH = 1.65 FT REQUIRED SURFACE AREA = 1.25 TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 1,515 SQ.FT. LEVEL 2 BIORETENTION G3 DIMENSIONS: PROPOSED SURFACE AREA = 2,569 SQ.FT., ELEVATION 358 FT SOIL MEDIA DEPTH = 3 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 35 INCHES, ELEVATION = 359 FT OUTLET BARREL LENGTH = 44 FT OUTLET BARREL DIAMETER = 18 INCHES US INV. ELEVATION = 354.5 FT, IDS INV. ELEVATION = 354.0 FT WATER QUALITY ORIFICE DIAMETER = 3.5 INCHES, ELEVATION = 358.5 FT UNDERDRAIN DIAMETER = 6INCHES, INVERT ELEVATION = 354.5 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 4 FT, ELEVATION = 362 FT MINIMUM EMBANKMENT TOP WIDTH = 5 FT MINIMUM SIDE SLOPE = 31 (INNER), 2:1 (DOWNSLOPE) AUXILIARY SPILLWAY WIDTH = 10 FEET, ELEVATION = 360.0 FT OUTLET PROTECTION: GIVEN: 18-INCH PIPE OUTFALL 10-YR DISCHARGE (Q) = 5.14 CFS OUTFALLS TO RIPRAP OUTLET PROTECTION A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 2 BIORETENTION G3 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 6INCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 5 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 5.5 FT LEVEL 2 BIORETENTION G1 HYDROLOGY SUMMARY To Q1 Q2 Q5 Q10 Q25 Q50 0100 CN (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 88.0 0.083 5.73 7.47 10.24 12.60 16.03 18.96 22.16 ROUTED 88.0 0.083 3.55 5.92 9.02 11.34 14.58 17.37 20.39 WSE35324 WSE3ri M WSE35348 WSE35 M WSE3ri M WSE3 71 WSE3 W LEVEL 2 BIORETENTION G2 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 Q50 Q100 ON (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 84.0 0.083 0.98 1.32 1.88 2.35 3.06 3.67 4.33 ROUTED 84.0 0.083 0.50 1.04 1.74 2.22 2.91 3.51 4.15 WSE35 W WSE 358.81 WSE3 ffi WSE358.88 WSE388.72 WSE3.ri875 WSE358.78 LEVEL 2 BIORETENTION G3 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 050 Q100 ON (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 82.0 0.083 2.51 3.33 4.65 5.78 7.42 8.83 10.37 ROUTED 82.0 0.083 0.29 1.75 3.76 5.14 6.83 8.21 9.68 WSE 3..1 WSE.14 WSE 3525 WSE 35 31 WSE3 38 WSE 359 WSE 359 \�44 \1i '♦♦ ` ♦� / ♦ o APPROXIMATE \ EXISTING TREE LINE (PER KIRK HUGHES & ASSOC. SURVEY) BCE \ EXISTING ROAD � (PER KIRK HUGHES & ASSOC. � \ SURVEY) Blossom Consulting and Engineering Inc. c 's EXISTING FENCE 1101 Professional Drive, Suite G PERMANENT RIGHT-OF-WAY DIVERSION PROPOSED TO DIVERT OFFSITE I (PER KIRK HUGHES & ASSOC. Williamsburg, VA 23185 p: 757-870-4825 C DRAINAGE TO DOWNSTREAM CHANNEL. SURVEY) (SEE LANDSCAPE AND SITE PLANS FOR SITE GRADING AND SWM-6 FOR \ EXISTING BUILDING REPRESENTATIVE CROSS-SECTION) \ ' \ (PER KIRK HUGHES & ASSOC.7 \� SURVEY) � � @ ti ��\� ���♦NI♦���♦ � Cam, �,, � / / \1.56 AC' EXISTING POWER POLE i \ ♦ - o (PER KIRK HUGHES & ASSOC. / '9\ \; I,� I, < I '^ *. SEE SHEET SWM-6 FOR REPRESENTATIVE / SURVEY) r ^ p� �� / ` © CROSS SECTIONS AND SEE SHEET .� • O/ ' / SWM-7 FOR PLANTING PLAN .♦ \ i R �� ♦ / \ \ EXISTING SIGN z \ \ (PER KIRK HUGHES & ASSOC. • PREVIOUSLY APPROVED PHASE 1 BMP♦�'�r l \ SURVEY) / " ',• /1 EXISTING MANHOLE //- _Ti M.H. .• \ / i A q I \ (PER KIRK HUGHES & ASSOC. �� �. V V \ 1♦♦ v ♦♦ / ��s SURVEY) 1, ♦ / \ O \ �' > S,�O \\ EXISTING CONTOURS / ♦ ♦. / \ k \ '\ \. (PER KIRK HUGHES & ASSOC. •sy � .\ \ \ ♦' �♦♦' �� �� �\ o° "��\` ♦♦' 0.96 AC . o SURVEY) KEY F Y k •s ��' � Veil v�IS 12 ! • ':� riN r 1�( s - i • • • � 1v � � :� . �\, /� � ` � IIIIIIIIIIIIIIIIIIIII,- '� • • • \ •r ryr�f r � �\ 11 1 1 �i / n;� 1 IIIIIIIIIIIIIIIII■- �•'• '� � �• - __ `` �� `� `.� 11._-�/� I,11 O ,,• IIIIIIIIIIIIIIIIIIIII,- \'►+�; RAI E�. VO CROSS SECTIONS AND SEE SHEET SWM-7 FOR PLANTING PLAN IS-. ,E: ALL OUTFALLS •• LEVEL 2 ETENTI• • SHALL BE D WITH OUTFALL PROTECTION VA. SWM SPECIFICATIONS (SEE SHEET SWM-1 9) rr� rc I / \ SCALE: I INCH = 5o FEET BMP 11 O' 50' 100' ♦t♦♦ ♦! 1^` CONTOUR INTERVAL = 2 FT N 200' H OF $PLT Dr�� v SCOTT C. BLOSSOM y Lac. No. 40287 �SIONAL Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER PLAN: BLOCK G -5 TH:C:kUwmr HileDropbox'ProjectsW05 RinnnaNElMDesign and AnaysistCADW05_RivannaPH2_SWM_REV24"IHiIIII 11, 2018 at 17:17ILayout: 5 SWM331kG 366------------------------------------------------------------------------------------------ 368 372 ----------------------------------------------------------------------------------------------------- PROPOSED GRADE 364 366 370 PROPOSED STABILIZATION PROPOSED GRADE SEEDING AND EC-2 MATTING PROPOSED STABILIZATION 362 PROPOSED 12-FT 364 368 SEEDING AND EC-2 MATTING SIDEWALK LEVEL 2 BIORETENTION FILTER (G1) SURFACE AREA LEVEL 2 BIORETENTION FACE ON FILTER (G2) 6, TOP OF BERM SURFACE AREA TOP OF BERM LEVEL 2 BIORETENTION FILTER (G3) 360 36" RCP RISER (INSIDE DIA. ELEV.=356.0 Ff 362 ELEV.=358.0 FT 366 SURFACE AREA EOOP F ER FT WITH METAL TRASHRACK AND PROPOSED STRUCTURAL ANTI -VORTEX PLATE FILL SEE NOTES SHEET SWM-20 PROPOSE PILLWAY WEIR CREST 36" RCP RISER (INSIDE DL9, PROPOSED -,RIM ELEVATION=353.0 FT UNDERDRAIN ELEV.=357.0 FT, BOTTOM PROPOSED STRUCTURAL WITH METAL TRASHRACKAND 358 UNDERDRAIN 3.5' ORIFICE @ ELEV.=352.5 FT 360 CLEANOUT WIDTH = 20 FT, 3:1 SIDE SLOPES 364 FILL SEE NOTES SHEET ANTI -VORTEX PLATE CLEANOUT SWM-20 RIM ELEVATION=359.0 FP SPILLWAY WEIR CREST SPILLWAY WEIR CREST TABILIZED OUTFACE iTYPJ URFACE ELEV. 352.0 FT PROPOSED GRADE URFACE ELEV.=356.0 FP 3.5" ORIFICE @ELEV. 358.5 FP ELEV. 360.0 FP, ELEV. 354.0 FT, BOTTOM 356 ry 3" SHREDDED HARDWOOD WIDTH = 10 FP 358 /3" SHREDDED HARDWOOD , (CLASS I RIPRAP, MIN. 362 PROPOSE 2-FT DF.PTHI BOTTOM WIDTH = 10 FP rG MULCH LAYER ON SURFACE MULCH LAYER ON SURFACE ti UNDERDRAIN URFACE ELEV. 358.0 FP g• EXISTING loom W3E=3s38o FT G w CLEANOUT "SHREDDED HARDWOOD N GRADE tomwsE=3s3s3FT PROPOSED $TRUCPURAL ram.' 354 - - - - 356 __ _ __ __ __ _ 360 MULCH LAYER ON SURFACE - - FILL SEE NOTES SHEET EXISTING-� r rr-- rr-- - G \ \ SWM-20 - - GRADE xl-I I=I_I1-_I I -I I -I I=I J=� m WSE=356.6. FT =I I�--III- -III -III-III-III- III -III -III -III -III -III -III -I ILomWSE=356.68FT I-III=1I I I1=1I I 11 - - - - .00m WSE-356J8 FT - - - - 1 m WSE=3s3.34 F T 1 � �_-_ � � �_-_ � � �_-_ � I I III -I I -III -I I-III-�-l-il. i il. I I I -I I -J 1= =J I 352 \ 354 11 --_ ---i 1=III-I 11=III-I 11=III-III-III-I I (-I I (-I I1=III-III-III III -III T I. I. LT- . 358 _ _ _ _ _ _ _ "I I�II�I�II�I I 36' RCP RISER (INSIDE DIA.) III -III ITI I1_ III I1--I 1=II1--II1=II1--III=1I1-_III 1 I --- --- PROPOSED ENGINEERE WITH METAL TRASHRACK AND -III- -III-I I H I_J I -III -I 1=I I -III -I I -III -I I / SOIL MIX (DEPTH=3 Fr) ANTI- VORTEX PLATE _ I I� I� I� I� I� = I I� I� I� T f', VDOT 350 III=III III=111=III=111=III=1 I-Rlsi I I I I-III=1 I I=1 woT Est 352 1 -I 1 1-I 1 1 _ _ 356 - �-I1=1 ITI ( ( I I-1 I-1 I-1 I - - -- SOT #8 STONE 6' PERFORATED PVC - TION_356.5 FT -! _ _ _ _ _ _ _ _ _ _ ES1 (18") 1 _-_ 1 _ 1 1 RIM ELEVA -I I -III -I III III III III III III III III ---III -III - --- 1 EXISTING ' ' -_-_ (4-INCH DEPTH) UNDERDRAIN (ELEV.=352.5) 40 FT 18" RCP 11 - PSOILOMIX (DEPTH-3 FT) 8' RCP 4 2%\ _ - 1 1 1 (SEE PLAN VIEW, SHEET 5 FOR US IIdV. 352.., FT _ 1 354 GRADE 4q i8., RCp @ 5% 348 48' -1 350 I_ --I --I I_ q. =�r=L+ \ _ BOTTOM ELEV.=351.67 FT FULL LAYOUT OF UNDERDRAINS) DS INV.=352.0 FI' 346 4 INCH DEPTH PEA GRAVEL \- ---- - --I --L - *NOTE: INSTALL 4" PEA GRAVEL LAYER PROPOSED ENGINEERE - 348 --- --- VDOT #57 STONE SUMP --- -ABOVE CROWN 4 UNDERDRAIN RAVEL AND 3 FT DEEP RISER BASE ---i 352 SOIL MIX (DEPTH=3 FT) LAYER ABOVE CROWN OF US INV.=348.o FT ---I I- l WITH BASE PLATE(SE E--I UNDERDRAIN DS INV.= 6.o FT - (OPEN GRADED, DO BE --- INSTALL FILTER FABRIC OVER US INV. 354.0 FF 34 --- ---1 ( - ) DETAIL I, THIS SHEET -- PVC CONCRETE FILLE ) _ �, E UNDERDRAIN RISER BASE (z' MINJ �- 1==� 111==� - i�- -_ UNDERDRAIN 1-2 FP TO EITHER SIDE - 4_INCH DEPTH PEA GRAVEL LAYER 5- DS INV. 352.0 FT WASHED (1-FOOT DEPTH)_--�11- - _- _ •40 -- 1-- PT UGLY CONCRETE UND - --- -_-=-��1--��1--��1--��1--��----------=�1�1--�11--��1--�J.1--� BASE ON RISER - 344 / 346 -- 350 ABOVE CROWN OF UNDERDRAIN IT _� 12-. CH STONE SUMP INSTALL 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1 +00 1 +10 1 +20 1 +30 1 +40 1 +50 1 +60 1 +70 1 +80 1 +90 2+00 2+10 ---1 1 1---1 1 1 -- - I INSTALL (OPEN GRADED) -T -1 I_ CRADLE ALONG CONDUIT --6-INCH SCHD. 40 PERFORATE - FILTER FABRIC OVER III I CRADLE ALONG CONDUlf I 342 ( ) VERTICAL SCALE: 1 4 HORIZONTAL SCALE 1 20 I TO (1-2FP - THIS I I I I I I I TO FILEPI'H R SIDE) ER FABRIC �R - (SEE DETAIL 3, THIS SHEET) 11= i u= _ -,I PVC � - -� -, T- EITHER N E) - - (SEE DETAIL I UNDERDRAIN (1-2 FT - / CROSS SECTION B-B' G2 348 C UNDERDRAIN 1 UN RDRAIID 340 STABILIZED OUTFALL-/// -INCH STONE SCRIP-- - -_ (CLASS I RIPRAP, MIN. 346 (OPEN GRADED) ABILIZED OUTFALL I -------------------------------------- 2-FT DEPTH) - 1444111114-4-41111 - (CLASS I RIPRAP, MIN. --I-I-1 I-1 I -I 1 1-I 1 1-I-I 1 I-1 I I-1-I-I-I 1 1-i 1 1- _--- 2-FT DEPTH) 11 .1 11 ___.1 11 ___.1 11 ___.1 11 ___.1 11 ___.1 11 ___.1 I I ___ 1 I 1 ___ 1 I 1 ___.1 11 ___.1 11 ___.1 11 ___.1 11_ 338-111---111----111----111----111----111----111_-111-=_111----111----111----111----111-- 11 344 - 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 1+80 1+90 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 CROSS SECTION A -A' (G1) CROSS SECTION C-C' (G3) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 30/ 356 355 354 353 352 351 -20 -15 -10 -5 0 5 DETAIL: BMP G1 WEIR SECTION VERTICAL SCALE: 1 "=2' HORIZONTAL SCALE 1 "=5' CLASSI RIPRAP (2-FT MIN. DEPTH) UNDERLAIN WITH GEOTEXTILE FABRIC I I I I I I 10 15 20 30L- 358 357 356 355 354 MENNENTOP OF BERM CLASS I RIPRAP­ MENEMUNDERLAIN WITH GEOTEXTILE FABRIC -20 -15 -10 -5 0 5 DETAIL: BMP G2 WEIR SECTION VERTICAL SCALE: 1 "=2' HORIZONTAL SCALE 1 "=5' �������❑��r��� YB" DIA. X 6" LG. ADHESIVE BOLTS r W/FLAT WASHERS AND L SELF LOCKING NUTS TYPICAL 8 PLACES -EQUALLY - L SPACED ON AN "E" DIA. B.C. LOCKABLE ACCESS SEE N SEE NOTE 1 E 1 I� ❑ SEE NOTE 18"DIAMETER CULVERT 1 CULVERT . es' .. .. .. .. fk 7.0' Y2" DIA. STEEL BAR Y" THICK - STEEL PLATE D MIN. % C MIN. 0 8' CIRCULAR 6" SQ. MAX. STORMWATER =- RISER I.D. MANAGEMENT RISER O.D. 3'-0" DIA. BASIN 4' 4" CLASS A-3 CONCRETE TO BE USED TO FILL SWM DRAINAGE STRUCTURE TO INVERT OF SIDE VIEW OUTLET PIPE. SWM DRAINAGE STRUCTURE 2" WIDE X Y4" THICK STEEL RING BOLTED TO RISER In" TYP. RISER DIMENSION APPROX. I.D. O.D. A B C D E SEGMENT WT. (LBS.) 36 44 42 6 13 18 40 zz 82 NOTES: L COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER METAL MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. NOTES: 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. L A HINGED, LOCKABLE ACCESS DOOR SHALL BE PROVIDED ON TRASH RACK 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR z ANTI -VORTEX PLATE IS TO BE USED WHEN SPECIFIED ON THE PLANS. COST OF 5. STEP DETAILS SEE STANDARD ST-1. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK FURNISHING AND PLACING THE ANTI -VORTEX PLATE IS TO BE INCLUDED IN THE 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1" WIDE HORIZONTAL STRIPES AT 1' BID PRICE FOR THE STRUCTURE. INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 3. SEE DESIGN CROSS SECTIONS (THIS SHEET) FOR ORIFICE ELEVATIONS. 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. �1 DETAIL: G1. G2, AND Gs LEVEL 2 BIORETENTION s6 INCH VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS 10 15 20 WATERTIGHT CAP & P.V.C. SCREW CAP ON TERMINAL END ON GRADE OF PIPE 6• P.V.C. NONPERFORATED / STANDPIPE ��•��• ♦.....� ���.��-rvv������� ♦................... 0? 000000.'.O�i�i'0000� r ■ ■ -■-. RECYCLED PLASTIC PIPE MAY BE SUBSTITUTED FOR PVC PIPE IF ALL CONVEYANCE AND ROUGHNESS CRITERIA ARE DEEMED ADEQUATE 2 DETAIL: PIPE CLEANOUT 6 NTS .500 362 361 360 359 358 357 CLASS RIPRAP (2-FT MIN. DEPTH) UNDERLAIN WITH GEOTEXTILE FABRIC I I I I I I -20 -15 -10 -5 0 5 10 15 20 DETAIL: BMP G3 WEIR SECTION VERTICAL SCALE: 1 "=2' HORIZONTAL SCALE 1 "=5' NOTES: 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH FLOWABLE FILL INSTEAD OF CONCRETE, t (thickness) = 3.011 PENDING APPROVAL BY DESIGN ENGINEER * SIDE WALLS MAY CONFORM TO THE SHAPE OF EXCAVATED TRENCH ** SHALL NOT BE LESS THAN 6" 8„ . a. 0 - 18 %2 (D + 2t) = 12" 4' %2 ID 2" %4 D OR 611 ( ' 1 DETAIL: CULVERT CONCRETE CRADLE BLOCK G: CLEAN WATER DIVERSION SWALE 364 00000000000000 362 360MOIR LINING 358 3560 5 10 15 20 DISTANCE (FT.) TYPICAL CLEAN WATER DIVERSION CROSS-SECTION VERTICAL SCALE: 1" = 2' HORIZONTAL SCALE: 1" = 5' NTS FLOTATION CALCULATIONS FOR RISER BASE (TYP.) GIVEN: WEIGHT OF WATER = 64.2o LBS/CU-FT WEIGHT OF CONCRETE=15o.00 LBS/CU-FT TOP INVERT OF RISER = 353.0 FT, NAVD88 INVERT OF UNDERDRAIN = 348.5 FT, NAVD88 INVERT OF CULVERT = 348.5 FT, NAVD88 BOTTOM INVERT OF RISER = 348.o FT, NAVD88 HEIGHT OF RISER = 4.5 FT RISER INSIDE DIAMETER = 3.o FT WALL THICKNESS = 4 INCHES RISER INSIDE AREA = 7.07 SF RISER OUTER AREA = 10.56 SF RISER BASE: RISER BASE AREA = 17.10 SF BASE DEPTH = 2.0 FT RISER OPENINGS: WATER QUALITY ORIFICE (3.5" DIAMETER) = 0.07 SF UNDERDRAIN ORIFICE (6" DIAMETER) = 0.20 SF OUTFALL CULVERT (18" OUTER DIAMETER) = 1.77 SF TOTAL AREA = 2.04 SF TOTAL VOLUME (AREA X 4") = o.68 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 47.52 CU-FT VOLUME OF BASE = 38.2 CU-FT TOTAL DISPLACED VOLUME = 85.74 CU-FT WEIGHT OF DISPLACED WATER = 5,35o LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE =15.71 CU-FT VOLUME OF OPENINGS = o.68 CU-FT TOTAL VOLUME OF RISER = 15.03 CU-FT WEIGHT OF RISER = 2,255 LBS WEIGHT OF BASE: VOLUME OF BASE = 38.2 CU-FT WEIGHT OF BASE = 5,73o LBS TOTAL DOWNWARD WEIGHT = 7,929 LBS FACTOR OF SAFETY =1.48 NOTE: 1) REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. 2) SEE HYDROLOGY SUMMARY PROVIDED ON SWM PLAN SHEETS AND SUPPLEMENTAL STORMWATER INFORMATION BOOKLET. RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA 13CE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 13:111INd,I_101 ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. H OF Dr�� �• z v SCOTT C. BLOSSOM y Lac. No. 40287 A �47 ��SSIONAL ����� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK G CROSS SECTIONS FILEPATH:C:\Users\Hill\DropboAProjeds\005 RivannaNEVNDesign and Analysis\CAD\005_RivannaPH2_SWM _ REV2.dvQIHi1llApr 11, 2018 at 17:171Layout 6 BI G (XS) SWM - 6 NOTE: 1) REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. 2) SEE HYDROLOGY SUMMARY PROVIDED ON SWM PLAN SHEETS AND SUPPLEMENTAL STORMWATER INFORMATION BOOKLET. RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA 13CE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 13:111INd,I_101 ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. H OF Dr�� �• z v SCOTT C. BLOSSOM y Lac. No. 40287 A �47 ��SSIONAL ����� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK G CROSS SECTIONS FILEPATH:C:\Users\Hill\DropboAProjeds\005 RivannaNEVNDesign and Analysis\CAD\005_RivannaPH2_SWM _ REV2.dvQIHi1llApr 11, 2018 at 17:171Layout 6 BI G (XS) SWM - 6 LEVEL 2 BIOFILTER PLANTING PLAN (G1,G2, & G3) N SCALE: I INCH = 3o FEET o' 301 6o' CONTOUR INTERVAL = 2 FT 1201 NOTES: L BMP Gi AND G3 RECEIVE 3 INCH SHREDDED HARWOOD MULCH (SEE NOTES ON SHEET 7AND VA DEQ STORMWATER DESIGN SPECIFICATION NO.9 (MARCH 1, 2011). 2. BMP G2 RECEIVES STABILIZATION SEED MIX IN LIEU OF MULCH (SEE PALETTE THIS SHEET). 3. ALL DISTURBED AREAS ON BMP SLOPES SHALL RECEIVE STABILIZATION SEED MIX AS SHOWN ON THIS SHEET. AUTOCAD FILE WILL BE SUPPLIED TO SELECTED CONTRACTOR CONTAINING GEOGRAPHIC COORDINATES OF ALL PROPOSED BMPS FOR LAYOUT, STARING AND AS BUILT SURVEY. LEVEL 2 BIORETENTION G1 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AA 6 ARONIA ARBUTIFOIA RED CHOKEBERRY #2 CONTAINER FAC #SP4 CONTAINERS SHALL BE BN 4 BETULA NIGRA RIVER BIRCH #7 CONTAINER FACW SPACED APPROXIMATELY 3 FEET ON CENTER. !ii>:CC 37 CONOCLINIUM COELESTINUM BLUE MIST FLOWER #SP4 CONTAINER FAC #2 AND #7 CONTAINERS SHALL CA 7 CORNUS AMOMUM SILKY DOGWOOD #2 CONTAINER FACW BE LOCATED AS SHOWN ON EV ` 46 ELYMUS VIRGINICUS VIRGINIA WILD RYE #SP4 CONTAINER FACW PLAN. Fp 55 EUPATORIUM PERFOLIATUM BONESET #SP4 CONTAINER FACW ANDROPOGON VIRGINICUS LB O LINDERA BENZOIN NORTHERN SPICEBUSH #2 CONTAINER FAC SHALL BE THE ONLY HERBACEOUS SPECIES USED PO 3 PLATANUS OCCIDENTALIS SYCAMORE #7 CONTAINER FACW ON BERMS WITHIN THE `0'PV'Si 52 PANICUM VIRGATUM SWrfCH GRASS #SP4 CONTAINER FAC BIORETENTION CELL. QM O QUERCUS MICHAUXII SWAMP CHESTNUT OAK #7 CONTAINER FACW `✓N 38 VERNONIA NOVEBORACENSIS NEW YORK IRONWEED #SP4 CONTAINER FACW VD 6 VIBURNUM DENTATUM ARROWWOOD VIBURNUM #2 CONTAINER FAC ANDROPOGON VIRGINICUS BROOMSEDGE BLUESTEM #SP4 CONTAINER FACU LEVEL 2 BIORETENTION G2 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AA O ARONIA ARBUTIFOIA RED CHOKEBERRY #2 CONTAINER FAC #2 CONTAINERS SHALL BE CA 8 CORNUS AMOMUM SILKY DOGWOOD #2 CONTAINER FACW LOCATED AS SHOWN AND SPACED 10 FEET ON CENTER. LB 3 LINDERA BENZOIN NORTHERN SPICEBUSH #2 CONTAINER FAC SIN 3 SALIX NIGRA BLACK WILLOW #2 CONTAINER OBL VD 3 VIBURNUM DENTATUM ARROWWOOD VIBURNUM #2 CONTAINER FAC LEVEL 2 BIORETENTION G2 STABILIZATION SEED MIX (1,589 S.F.) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES 1 AGROSTIS PERENNANS AUTUMN BENTGRASS SEED FACU APPLY SEED AT RATE OF TO ANY DISTURBED DD AREAS NOT ALREADY STABILIZED. APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. 15 CHAMAECRISTA FASCICULATA PARTRIDGE PEA FACU 5 CHASMANTHIUM LATIFOLIUM RIVER OATS FACU 15 ELYMUS VIRGINICUS VIRGINIA WILD RYE FACW 1 EUPATORIUM PERFOLIATUM BONESET FACW 2 HELENIUM AUTUMNALE COMMON SNEEZEWEED FACW 5 PANICUM RIGIDULUM REDTOP PANIC GRASS FACW 5 PANICUM VIRGATUM SWITCH GRASS FAC 25 SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM FACU 5 SIENNA MARILANDICA MARYLAND SENNA FAC 15 SORGHASTRUM NUTANS INDIAN GRASS FACU 5 TRIDENS FLAVUS PURPLE TOP FACU 1 VERNONIA NOVEBORACENSIS NEW YORK IRONWEED FACW LEVEL 2 BIORETENTION G3 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AA 6 ARONIA ARBUTIFOIA RED CHOKEBERRY #2 CONTAINER FAC #SP4 CONTAINERS SHALL BE BIN 4 BETULA NIGRA RIVER BIRCH #7 CONTAINER FACW SPACED APPROXIMATELY 3 FEET ON CENTER. ........................ ; 38 CONOCLINIUM COELESTINUM BLUE MIST FLOWER #SP4 CONTAINER FAC #2 AND #7 CONTAINERS SHALL CA 6 CORNUS AMOMUM SILKY DOGWOOD #2 CONTAINER FACW BE LOCATED AS SHOWN ON 43 ELYMUS VIRGINICUS VIRGINIA WILD RYE #SP4 CONTAINER FACW PLAN. 43 EUPATORIUM PERFOLIATUM BONESET #SP4 CONTAINER FACW ANDROPOGON VIRGINICUS LB O LINDERA BENZOIN NORTHERN SPICEBUSH #2 CONTAINER FAC SHALL BE THE ONLY HERBACEOUS SPECIES USED PO 3 PLATANUS OCCIDENTALIS SYCAMORE #7 CONTAINER FACW ON BERMS WITHIN THE 33 PANICUM VIRGATUM SWrfCH GRASS #SP4 CONTAINER FAC BIORETENTION CELL. QM 3 QUERCUS MICHAUXII SWAMP CHESTNUT OAK #7 CONTAINER FACW vM:;:>;;:;:>;;:; 32 VERNONIA NOVEBORACENSIS NEW YORK IRONWEED #SP4 CONTAINER FACW VD 6 VIBURNUM DENTATUM ARROWWOOD VIBURNUM #2 CONTAINER FAC ::•ii:•i4V'.:::•ii::•ii 12 ANDROPOGON VIRGINICUS BROOMSEDGE BLUESTEM #SP4 CONTAINER FACU TYPICAL BIORETENTION FACILITY PROVIDED FOR ILLUSTRATIVE PURPOSES ONLY BLOCK G -PERMANENT STABILIZATION SEED MIX (0.51 AC.) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES APPLY SEED AT RATE OF 200 LBS./AC. 90 FESTUCA ARUNDINACEA TALL FESCUE FACU SEED APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW 10 POA PRATENSE KENTUCKY BLUEGRASS FACU MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 1:1211INAVE 13:va,I_1ki ISSUE IREV # I DATE I DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. TH pF Dr�f v SCOTT C. BLOSSOM y Lac. No. 40287 ADO �W� �ZSSIONAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK G: PLANTING SWM - 7 FILEPATH:C9U"mr HiIBDropbox\Projects\005 RivannaNENADesign and Analysis\CAD=5_RivannaPH2_ SWM_ REV2.d"lHilllApr 11, 2018 at 17:171Layout: 7 Plant 8 Detail Blk G 64.101:1ODAT%10:11ZI•R1►►_1ei:1l•I:11NIL IIKOL•1Ito1e1WAN 0101064 LEVEL 2 BIORETENTION 12/13 LEGEND CALCULATIONS: DRAINAGE AREA = 4.46 ACRES RUNOFF REDUCTION TREATMENT VOLUME = 6,523 OF EFFECTIVE STORAGE DEPTH = 1.65 FT REQUIRED SURFACE AREA = 1.25 X TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 4,942 SF LEVEL 2 BIORETENTION 12/13 DIMENSIONS: PROPOSED SURFACE AREA = 5,586 SF, ELEVATION 351.8 FT SOIL MEDIA DEPTH = 3 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 36 INCHES, ELEVATION = 352.8 FT OUTLET BARREL LENGTH = 100 FT OUTLET BARREL DIAMETER = 18 INCHES, INV. US 348.5 FT, INV. DS = 347.5 FT WATER QUALITY ORIFICE DIAMETER = 3.5 INCHES, ELEVATION = 352.3 FT UNDERDRAIN DIAMETER = 5INCHES, INVERT ELEVATION = 348.0 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 2.2 FT, ELEVATION = 354 FT MINIMUM EMBANKMENT TOP WIDTH = 5 FT MINIMUM SIDE SLOPE = 3:1 (INTERNAL & DOWNSTREAM), RETAINING WALL ALONG ROAD AUXILIARY SPILLWAY WIDTH = 10 FEET, ELEVATION = 353.3 FEET OUTLET PROTECTION: GIVEN: 18 INCH PIPE OUTFALL 1 O-YR DISCHARGE (Q) = 19.48 CFS OUTFALLS TO GRASSY SLOPE A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 2 BIORETENTION 12/13 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 8 INCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 16 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 17.5 FT LEVEL 2 BIORETENTION 12/13 HYDROLOGY SUMMARY Tc 01 Q2 Q5 Q10 025 Q50 Q100 ON (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 81 0.169 7.97 11.04 16.15 20.50 27.16 32.84 39.07 ROUTED 81 0.169 3.74 8.09 14.62 19.48 25.97 30.88 36.23 WSE 353.05 WSE 35322 WSE 3Ci3.4 WSE 353.50 WSE3M1 WSE 353.73 WSE 353.89 LEVEL 2 WET POND 11 CALCULATIONS: ONSITE DRAINAGE AREA = 44.3 ACRES OFFSITE DRAINAGE AREA = 53.4 ACRES TOTAL DRAINAGE AREA = 97.7 ACRES RUNOFF REDUCTION TREATMENT VOLUME (ONSITE) = 1.5-77,874 = 116,811 OF RUNOFF REDUCTION TREATMENT VOLUME (OFFSITE) = 1.5'63,807 = 95,711 OF TOTAL RUNOFF REDUCTION TREATMENT VOLUME = 212,522 OF (4.88 AC -FT) STORAGE PROVIDED AT NORMAL POOL = 179,907 OF (4.13 AC -FT) STORAGE PROVIDED 1-FT ABOVE N.P. = 55,562 OF (1.28 AC -FT) TOTAL STORAGE PROVIDED = 179,907 + 55,562 = 235,459 OF (5.41 AC -FT) VOLUME PROVIDED > VOLUME REQUIRED LEVEL 2 WET POND 11 DIMENSIONS: PROPOSED FOOTPRINT = 87,578 SF (2.0 AC) AT ELEVATION 344 FT MIN. PROPOSED SURFACE AREA AT NORMAL POOL (340 FT) = 47,008 SF (1.08 AC) MINIMUM FLOW PATH LENGTH = 250 FT MINIMUM WET DEPTH = 6 FT, BOTTOM ELEVATION = 334 FT OUTLET RISER HEIGHT = 8 FT, ELEVATION = 342 FT OUTLET RISER = 84 INCH DIAMETER RCP RISER OUTLET BARREL LENGTH = 55 FT OUTLET BARREL DIAMETER = 60 INCHES, INV. US = 336 FT, INV. DS = 335.5 FT DEWATERING ORIFICE DIAMETER = 18 INCHES, ELEVATION = 340 FT EMERGENCY WEIR LENGTH = 50 FT, ELEVATION = 343.5 DRY HEIGHT = 6 FT, ELEVATION = 346 FT MINIMUM EMBANKMENT TOP WIDTH = 12 FT MINIMUM EXCAVATION SIDE SLOPE = 5:1 MINIMUM EMBANKMENT SIDE SLOPE = 3:1 OUTLET PROTECTION: GIVEN: 60 INCH RCP OUTFALL PARABOLIC RECEIVING CHANNEL TOP WIDTH (T) = 12 FT CHANNEL SLOPE (S) = 0.05 FT/FT CHANNEL ROUGHNESS (n) = 0.035 1 O-YR DISCHARGE (Q) = 279.9 CFS HYDRAULIC RADIUS (R) = [(r ^ 2)d) / {[1 .5(T ^ 2)]+[4(d ^ 2)]) FLOW AREA (A) = (2/3)Td Q = (1 .49/n)[R ^ (31][S ^ &A Qn / 1.49 [S ^ (z] = A[R ^ & 0.048 = (2/3)12d f[(144d) / (216 + 4(d ^ (2))] ^ (0} FLOW DEPTH (d) = 0.06 FT SINCE 0.06 FT < (1/2) PIPE DIAMETER OF 60 INCHES, A MINIMUM TAILWATER CONDITION EXISTS USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 2 WET POND BMP 11 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 1.3 FEET (CLASS II RIPRAP) MINIMUM APRON LENGTH = 42 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 47 FT LEVEL 2 WEfPOND 11 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 Q50 Q100 ON (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 79.5 0.307 126.68 180.05 269.68 348.84 456.72 569.43 582.09 ROUTED 79.5 0.307 35.32 82.74 179.17 279.93 398.53 499.59 609.43 WSE34252 WSE34 WSE34374 WSE344.11 WSE 344.57 WSE 34491 WSE 34524 BMP 11 (WET POND L2) STAGE STORAGE: STAGE -STORAGE BMP II ELEVATION (FT) AREA (ACRES) CUMULATIVE VOL. (CF) CUMULATIVE VOL. (AC -FT) 334.0 0.396 0 0.00 336.o 0.589 42,630 o.98 338.o 0.757 101,122 2.32 338.5 0.815 118,236 2.71 340.0 1.079 179,907 4.13 340.5 1.304 205,819 4.73 341.0 1.420 235,469 5.41 342.0 1.769 304,783 7.00 344.0 2.011 469,314 10.77 346.o 2.522 666,346 15.30 WET POND NOTES: 1. BMP I1 IS A WET POND LEVEL 2 (WP2) DESIGNED TO TREAT PORTIONS OF PHASE 1 AND PHASE 2 DEVELOPMENT. INTERIM BMP CS2 ON PHASE 1 PLANS IS NOT REQUIRED IF BMP I1 IS CONSTRUCTED TO TREAT PROPOSED DRAINAGE AREA DEPICTED HEREIN. 2. BMP Il (WP2) TREATS A SIGNIFICANT PORTION OF OFFSITE DRAINAGE AREA AND IS SIZED TO PROVIDE SUFFICIENT Tv TO ACCOUNT FOR OFFSITE LOADING. HOWEVER, SITE COMPLIANCE IS ACHIEVED BY PROVIDING REMOVAL REQUIRED FOR ONSITE LOADING. 3. ADDITIONAL STORAGE'ABOVE' NORMAL POOL PROVIDES DETENTION REQUIRED FOR ENERGY BALANCE COMPLIANCE. 4. SEE MASTERPLAN SUMMARY (SWM-4) SHEET FOR ASSOCIATED VRRM AND ENERGY BALANCE SUMMARY. M NOTE: WET POND LEVEL 2'OVERSIZED' TO ACCOUNT FOR POTENTIAL FUTURE DEVELOPMENT M PROPOSED LIMITS � OF DISTURBANCE OSITE BENCHMARK (PER ROUDABUSH, GALE AND ASSOC. SURVEY) y+� EXISTING WETLANDS (PER KIRK HUGHES & ASSOC. y`. SURVEY) OEXISTING STREAM CHANNEL LIMITS (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING POND (PER KIRK HUGHES & ASSOC. SURVEY) APPROXIMATE EXISTING TREE LINE (PER KIRK HUGHES & ASSOC. SURVEY) �. EXISTING ROAD � (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING FENCE (PER KIRK HUGHES & ASSOC. SURVEY) ®EXISTING BUILDING (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING POWER POLE o. (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING SIGN os (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING MANHOLE M.H. (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING CONTOURS � (PER KIRK HUGHES & ASSOC. SURVEY) 0 EXISTING STREAM BUFFER (PER ALBEMARLE COUNTY) 0 PROPOSED BIORETENTION FILTER ENGINEERED SOIL MEDIA PROPOSED OUTFALLPROTECTION PROPOSED CONTOURS PROPOSED SWM BMP DRAINAGE AREA DIVIDES 9DA G3 PROPOSED SWM BMP as Ac DRAINAGE AREA LABELS OPROPOSED 6-INCH PVC UNDERDRAINS ® PROPOSED SAFETY BENCH OPROPOSED AQUATIC BENCH/WETLAND AREA PROPOSED OPEN WATER PROPOSED WET POND (BMP I1) � DRAINAGE AREA DIVIDE ICI SCALE: I INCH = 8o FEET 8o' 16o' 320' RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA 13CE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 KEY P ISSUE IREV # I DATE I DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. TH pF Dr�f � x v SCOTT C. BLOSSOM y Lac. No. 40287 O INNAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK I & J: STORMWATER PLAN SEE SHEET 11 & 12 FOR LEVEL 2 BIORETENTION I2 AND I3 DETAILS AND PLANTING PLAN. CONTOUR INTERVAL = 2 FT SWM-8 JOV — JOV Table 14.4. Clay Liner Specifications Table 14.5. Required Groundwater Protection Liners for Ponds I in Karst Terrain (WVDEP 2006 and Virginia Stormwater Management Handbook 1999) 358 I 356 354 EXISTING GRADE Source: Virginia Stormwater Management Handbook (1999) \ 352 \ -7BMP 11 350 WE AREA 358 356 354 352 350 STOP OF BERM Source: WVDEP (2006) and Virginia Stormwater Management Handbook (1999) 348 \ ELEV.=341.o FT ALTERNATIVE CONSISTENCY INCLUDING BENTONITE MAY BE APPROVED BY 348 ENGINEER IN CONJUNCTION WITH MODIFICATION OF DESIGN DEPTH. \ LEVEL 2 WET POND (BMP 11) 346 TOP OF BERM 346 iooYR ELEV.=345.24 FT / ELEV.=346.5 FT - III —III IIIIIIIIII IIIIIII IIIlIII IIIIIII IIIlIII IIIIIII IIIlIII IIIIIII IIPRIlI—IOIIPOIIIIISEID GRADE IlI �10YRELEV.= 11FT ^i+I / III— III— II I IROII PIOIS1 EDSII TI7IUCTT1 II RI L344 I II I I IIII II I�II I I I 344WWCSSEE SHEET ELEV. O..O Fr.BOTTOM = SWM-20 WIDTH FT 1 IDE SLOPES 1YR ELEV. 2. 2 FT 342342 11I ............... 340 NORMAL POOL ELEV. O.OFT 340 SAFETY BENCH PROPOSED TOPSOIL ABO 10-FTWIDTH 338 CLAY LINER (6-8" MIN. DEPTH) AQUATIC BENCH 338 AQUATIC BENCH }10-FTWIDTH BOTTOM OF WETLANDELEVWIDTH 18" DEPTH 33 I DEPTH336 STABILIZED OVERFLOW (CLASS I IUNDERLAIN IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII—III 334 I—IIIIIIIIIIII—III— WITH GEOTEXTILE FABRIC) —III —III PROPOSED CLAY LINER)J IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII 334 MIN 2-FT DEPTH. PER VASWM SPECS. OR IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII— III (SEEEDETAIL THISSHEET)—I I � � �— EOETTO 300PFOTND= 33-111-11 -- 332 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10 2+20 2+30 2+40 2+50 2+60 2+70 2+80 2+90 3+00 3+10 3+20 3+30 3+40 3+50 3+60 3+70 3+80 3+90 4+00 4+10 CROSS SECTION D-D' (BMP 11) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 Property Test Method Unit Specification Permeability ASTM D-2434 Cm/sac 1 x 10,13 Plasticity Index of Clay ASTM D-4231424 % Not less than 15 Liquid Limit of Clay ASTM D-2216 % Not less than 30 Clay Particles Passing ASTM D-422 % Not less than 30 Clay Compaction ASTM D-2216 % 95% of standard proctor density RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BICE Blossom Consulting and Engineering Inc. 1101 Professional Drive Williamsburg VA 23185 1 757-870-4825 356 354 352 350 348 346 344 342 340 338 336 334 332 330 Situation Criteria 24 inches of soil with a maximum hydraullo Pond not excavated to bedrock conductivity of 1 x I e cm/sec. Pond excavated to or near bedrock 24 inches of clay with a maximum hydraulic oond uctivity of 1 x 10's cmisec. Pond excavated to bedrock within a wellhead protection area, in a recharge area for a domestic Synthetic liner with a minimum thickness of 60 mi. well or SDrinci. or in a known faulted or folded area Clay properties as follows: Plasticity Index of Clay = Not less than 15% (ASTM D-4231424) Liquid Limit of Clay = Not less than 30% (ASTM D-2216) Clay Particles Passing = Not less than 30% (ASTM D-422) Clay Compaction = 95% of standard proctor density ASTM D-221 fi 356 354 352 350 348 346 KEY PLAN 344 342 340 338 336 334 ISSUE 332 REV # DATE DESCRIPTION 1 03.02.2018 PER COUNTY COM 330 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10 2+20 2+30 2+40 2+50 2+60 2+70 2+80 2+90 3+00 3+10 3+20 3+30 3+40 3+50 3+60 3+70 3+80 3+90 4+00 4+10 4+20 4+30 4+40 4+50 4+60 4+70 4+80 4+90 5+00 5+10 5+20 5+30 5+40 5+50 5+60 5+70 5+80 CROSS SECTION D1-D1' (BMP 11) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 354 352 350 348 346 344 342 340 338 336 334 332 354 352 350 348 346 344 342 340 338 336 334 332 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10 2+20 2+30 2+40 2+50 2+60 2+70 2+80 2+90 3+00 3+10 3+20 3+30 3+40 3+50 CROSS SECTION D2-D2' (BMP 11) `TOPSOIL: THE SURFACE LAYER OF COMPACTED FILL SHOULD BE VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 SCARIFIED PRIOR TO PLACEMENT OF AT LEAST 6 INCHES OF TOPSOIL. THE TOPSOIL SHALL BE STABILIZED IN ACCORDANCE WITH THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LATEST EDITION. INSTALL PUMP WET WELL IN ACCORDANCE WITH VA BMP GUIDE SPECIFICATION 14 TO FACILITATE DE -WATERING. ADDITIONAL INFORMATION TO BE PROVIDED IN MAINTENANCE AGREEMENT. NOTES: 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH FLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER * SIDE WALLS MAY CONFORM TO THE SHAPE OF EXCAVATED TRENCH ** SHALL NOT BE LESS THAN 6" %2 (D + 2t) = 33" %2 D=5", t (thickness) = 3.0" 1� %4 D=15" 1 NOTE: PER GEOTECHNICAL RECOMMENDATIONS PROVIDED BY VIOLA ENGINEERING AND PERVA. STORMWATER MANAGEMENT BMP STANDARDS AND SPECIFICATIONS, CONCRETE CRADLE SHALL BE INSTALLED ALONG ENTIRE LENGTH OF PRINCIPLE SPILLWAY BARREL. 1 DETAIL: CULVERT CONCRETE CRADLE 9 NTS FLUTAXION CALCULATIONS FOR KISER (11) rftl Zi WEIGHT OF WATER = 64.2o LBS/CU-FT WEIGHT OF CONCRETE = 150.00 LBS/CU-FT TOP INVERT OF RISER = 342.o FT, NAVD88 INVERT OF WQ ORIFICE (18" DIAM.) = 340.0 FT, NAVD88 INVERT OF CULVERT (6o" DLAM.) = 336.o FT, NAVD88 BOTTOM INVERT OF RISER = 333.0 FT, NAVD88 HEIGHT OF RISER = 9.o FT RISER INSIDE DIAMETER = 7.o FT WALL THICKNESS = 8 INCHES RISER INSIDE AREA - 38.48 SF RISER OUTER AREA = 54.54 SF RISER BASE: RISER BASE AREA = 73.39 SF BASE DEPTH = 3.0 FT RISER OPENINGS: WATER QUALITY ORIFICE (18" DIAMETER) = 1.77 SF OUTFALL CULVERT (6o" DIAMETER) = 19.63 SF TOTAL AREA = 21.4 SF TOTAL VOLUME (AREA X 4") =14.3 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 327.2 CU-FT VOLUME OF BASE = 224.8 CU-FT TOTAL DISPLACED VOLUME = 552.0 CU-FT WEIGHT OF DISPLACED WATER = 34,447 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE = 96.3 CU-FT VOLUME OF OPENINGS = 14.3 CU-FT TOTAL VOLUME OF RISER = 82.0 CU-FT WEIGHT OF RISER = 12,30o LBS WEIGHT OF BASE: VOLUME OF BASE = 224.8 CU-FT WEIGHT OF BASE - 33,72o LBS WEIGHT OF SOIL: =2,126 LBS TOTAL COUNTERWEIGHT = 48,155 LBS FACTOR OF SAFETY =1.39 NOTE: GEOMETRY OF CONCRETE BASE (LE. WIDTH) MAY BE MODIFIED TO ATTAIN ADEQUATE VOLUME OF CONCRETE FILL SPECIFIED IN FLOATATION CALCULATIONS. ALTERNATE ANCHORING (I.E. STEEL PLATE PER VA SWM SPECS.) MAY BE APPROVED BY ENGINEER. TH OF Dr�f � x v SCOTT C. BLOSSOM y Lac. No. 40287 ADO INNAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK I & J: PROFILE AND SECTIONS (1) SWM 9 FILEPATH:C:\Users\HixlDropbox\Projects\005 RivannaNENADesign and Analysis\CADW05_RivannaPH2_SWM_REV2.EvglHillli 11, 2018 at 17:171Layoul: 9 Bmp 11 (XS) �Y FOREBAY #3: HIGH FLOW SPILLWAY I ; /, TO WET POND STABILIZED INFLOW\ CHANNEL p< \ PROPOSED FIVE (5) 1 INCH CALIPER Y BMP 11 + RIVER BIRCH PLANTINGS ADJACENT TO EXISTING CHANNEL /r/ r B 5) \ \ S `3 rrrr / rrr /,r rrr d rr//r rrrr I rr \ �� ��:� � � � III \--�\�\:�. ' //r � /r// / •.rrrr/ rrrr rrrr// / // ' . ���� /r / •,,,, / rrrr/ /r/ / r/ rrrr /rrr / / 6 j rrrr /rrr r\\ / <� 336 \\1 �)lz / \ d PROPOSED MODIFIED CROSS VANE AT BMP CONFLUENCE WITH l `- TRIBUTARY CHANNEL (SEE DETAIL 1, SHEET SWM-20). 50 / A PROVIDE CLASS II RIP RAP CHANNEL DOWNSTREAM OF VANE (MIN. DEPTH 2.5FEET) TOP DRESS WITH H 6-INCH DIAMETER ROUNDED RIVER COBBLE (MIN DEPTH 6INCHES). BOTTOM WIDTH OF CHANNEL = 4 FT. FLOW DEPTH = 2 FEET. 2:1 SIDE SLOPES LINED WITH CLASS II RIP RAP. EXTEND TO NORMAL POOL. FOREBAY #2: HIGH FLOW SPILLWAY TO WET POND STABILIZED INFLOW �. CHANNEL. CLASS II RIP (MIN DEPTH ` 2.5 FEET_ TOP DRESSED WITH 6 INCH DIAMETER ROUNDED RIVER COBBLE (MIN DEPTH 6 INCHES) LOW FLOW SPILLWAY TO WETLAND BENCH (ELEV. - 341 FT) CLASS I RIP RAP (MIN DEPTH 2 FEET) TOP DRESS WITH 6 INCHES OF 6 INCH DIAMETER ROUNDED RIVER COBBLE) CONSTRUCTED WETLAND BENCH) + LOW FLOW SPILLWAY TO WETLAND BENCH (ELEV. - 341 FT) CLASS I RIP RAP (MIN DEPTH 2 / r FEET) TOP DRESS WITH 6 INCHES OF 6 INCH DIAMETER ROUNDED \ RIVER COBBLE) / ,,, , , „ r /r /r/ // /r// '��, �, �, ��� "9 \• FOREBAY #2: HIGH FLOW SPILLWAY r r r r / r ' rh ' / PO 6 ' / r ' " '�� ` TO WET POND STABILIZED INFLOW PROPOSED SIX (6) 1 INCH CALIPER / r r r r r / l' / ( /" r ' / / / / / / r r \ CHANNEL. CLASS II RIP (MIN DEPTH SYCAMORE PLATINUS 'r �/ �"\ ( 2.5 FEET TOP DRESSED WITH 6INCH OCCIDENTALIS) PLANTINGS ON BERM BETWEEN WETLAND POCKET AND r / r / / /✓ / /xx /X / /n" � SAFETY BENCH / hh PROPOSED EMERGENCY SPILLWAY WEIR BMP 11 MIN 3 FT DEPTH CLASS II RIP RAP UNDERLAIN (POND) WITH GEOTEXTILE FILTER FABRIC CREST ELEVATION = 343.5' CREST WIDTH = 50 FT 6i 3:1 SIDE SLOPES 34 \ // // /, rrr r/ r/ `;..• i % i 341 \ // rrr rrr // // // •�. .�•; � � /r >v r/ ///r/ / //// r r \ \ r/ /// // rr r/ rr '•\ // /i' \ / //�W�.`// //rrr r /'iii. it '/ i// } \ Yr rrrrT rr r r .rrrr rrrr/ �/i rr/r .X(X.r.C��/�r rrl �,/(Y /' .rrrr r/ r rrrr, /rrr ) . r/r r rrrr ///rrr r/ rrr Xr /. EXISTING STREAM BUFFER /'/ ;; /I;;; rrr, r /;;r%X `,(r r DIAMETER ROUNDED RIVER COBBLE (MIN DEPTH 61NCHES) / / / / / / / ` ' ,'„ ' ✓ / / PROPOSED MAINTENANCE ///r rr r/ W. E. ��/// rr/ ' / �/ _ ri "— .— _ ,ik" ' ' •—�c _/i'/ii iii/i'ii/ii PROPOSED MAINTENANCE ACCESS (SEE SHEET SWM-25) I345. XI 15, PROPOSED 10 FT AQUATIC BENCH , // // / ///rr/ (SEE PLANTING PLAN THIS •`� /// / SHEET) ✓ PROPOSED PRINCIPAL SPILLWAY 84 INCH RISER @ 342' 60 INCH CULVERT @ 336' 18 INCH LOW FLOW ORIFICE @ 34G (SEE DETAILS SHEET SWM-11) PROPOSED CLASS II RIP RAP OUTFALL PROTECTION MIN DEPTH = 2.5 FT LENGTH = 25 FT, WIDTH = 40 FT. INSTALL VDOT EW-2PC AT PIPE OUTFALL. SEE DETAIL SHEET SWM-19) SCALE: >, INCH = go FEET 3 42.2 r/// /rr /rrr /// I• , Si// / / FETY BENCH STABILIZED WITH ,r/ .///r//✓i>i 1//rr /// // //// r/ r/ r/ / STABILIZATION SEED MIX AS SPECIFIED ON THIS SHEET y� �Ti/1r1///// rrr/ rrr r rrr/rirrirrirr/" / i u y ✓�� r7�rirr/r r//r /r/! l�rr/ I \BMPJ / (D Y SW LE I 3s V I �l I 33�.2 I i ;►; ' BN I 4� ; r It Ic LEGEND PROPOSED SEDIMENT FOREBAY/HIGH FLOW CHANNEL PROPOSED LOW FLOW CHANNEL/SPILLWAY PROPOSED CONTOURS ® PROPOSED SAFETYBENCH PROPOSED AQUATIC BENCH/WETLAND AREA PROPOSED OPEN WATER PROPOSED MODIFIED CROSS VANE (AT CONFLUENCE) SEE DETAIL 1 SHEET SWM-20 PROPOSED CLASS II RIPRAP PROPOSED CLASS IRIPRAP i ■■■■■■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■ BMP I1: FOREBAY 1&2 HIGH FLOW SPILLWAY PICAL SECTION 346 000000000000000 No IN' =0 344CAPACITY = 142 CPS 342 340 3380 10 20 30 40 DISTANCE (FT.) TYPICAL HIGH FLOW SPILLWAY CROSS-SECTION VERTICAL SCALE: 1" = 4' HORIZONTAL SCALE: 1" = 1o' ■■■■■■�■■�i �"i�ii�W�i'iiii■■�i■■■■■ ■■■■■■■■■■■■■■■■■■■■ AUTOCAD FILE WILL BE SUPPLIED TO SELECTED CONTRACTOR CONTAINING GEOGRAPHIC COORDINATES OF ALL PROPOSED BMPS FOR LAYOUT, STAKING AND AS BUILT SURVEY. LEVEL 2 WET POND 11 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES BN 5 BETULA NIGRA I RIVER BIRCH #7 CONTAINER FACW PO 6 PLATANUS OCCIDENTALIS I SYCAMORE #7 CONTAINER FACW NOTE: DETAILED LANDSCAPE PLANTING DESIGN WILL BE INCLUDED WITH STAGE 4 PLAN SET. SOIL SPECIFICATION: AMENDED SOIL SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC MATTER; AND HAVE A PHOSPHORUS CONTENT OF 7 TO 21 m9/k9 OR A P-INDEX OF 10 TO 30. (PER VIRGINIA DCR STORMWATER DESIGN SPECIFICATION NO.9) PERMANENT STABILIZATION SEED MIX BMP 11 (1.85 AC.) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES APPLY SEED AT RATE OF 200 LBS./AC. 90 FESTUCA ARUNDINACEA TALL FESCUE FACU SEED APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW 10 POA PRATENSE KENTUCKY BLUEGRASS FACU MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. NOTE: ALL DISTURBED AREAS INCLUDING EMBANKMENT SLOPES SHALL BE HYDROMULCHED AT THE RATES SPECIFIED HEREIN. LEVEL 2 WET POND 11 PLANT PALETTE: WETLAND AREAS (9,932 S.F.) LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES 151 ALISMA SUBCORDATUM WATER PLANTAIN OBL #SP4 CONTAINERS SHALL BE SPACED APPROXIMATELY 3 FEET ON CENTER. PLANTS 81 CAREX VULPINOIDEA FOX SEDGE OBL 81 CHELONE GLABRA TURTLE HEAD OBL SHALL BE INSTALLED FROM NORMAL POOL ELEVATION TO (12) TWELVE INCHES BELOW 81 HIBISCUS MOSCHEUT08 SWAMP ROSE -MALLOW OBL 81 JUNCUS EFFUSUS SOFTRUSH FACW NORMAL POOL. 81 LOBELIA CARDINALSCARDINAL FLOWER #8P4 CONTAINER FACW 81 PELTANDRA VIRGINICA ARROW ARRUM OBL DISTRIBUTE PLANTS RANDOMLY AMONG SPECIES IN MINIMUM GROUPS OF 12 BY 151 SAGITTARIA LATIFOLIA DUCK POTATO OBL 151 SAURURUS CERNUUS LIZARD'S TAIL OBL SPECIES. LOCATE PLANTS ACCORDING TO INDICATOR STATUS. 81 SCHOENOPLECTUS TABERNAEMONTANI SOFT STEM BULRUSH OBL 81 SPARGANIUM AMERICANUM AMERICAN BUR -REED OBL NOTE: REFER TO LANDSCAPE AND CIVIL SITE PLANS FOR ADDITIONAL LANDSCAPE PLANTING DETAILS. RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA 13CE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 KEY P ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. o�ePLT H OF Dr�� I� z v SCOTT C. BLOSSOM y Lac. No. 40287 o �W� ��SSIONAL ����� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK I & J: DESIGN NOTES AND PLANTING (1) o' 30' 6o' CONTOUR INTERVAL = N/A FILEPATH:C:\Users\HilgDropboz\Projects\005 RivannaNENADesign and Analysis\CADW05_RivannaPH2_SWM_REV2.tivgHillApr 11, 2018 at 17:18Layoul: 10 Blk 11 Planting SWM - 10 363- PROF 362 361 III\ ? 358- I EXISTING \ GRADE -III 356-- 354 IIIIIIIIII 352 IIIIII-III IIIIIII I I 350 �IIII IIIIIIIII� I 348 IIIIIIIIII 346-1IIIIIIIIIIIIIIIIIIIIIIII ■ ELZ351.8 Fr ' B■Bad r ■■■ ' ■■■■■■% ■■■■ .%%o■■■■%►i■■.�■■■■■■■■■■■■ 344 III III III III III III III III III III III III III III III � 344 34211 III III IIIIIIIIIIIIIIIIIIIIIIIIIII1 � GI I I-III-1 I �IIII 1342 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 CROSS SECTION F-F' (BMP 12/13) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 000 354 353 352 351 350 CLASS IRIPRAP (2-FT MIN. DEPTHj- UNDERLAIN WITH GEOTEXTILE FABRIC -20 -15 -10 -5 0 5 10 15 20 DETAIL: BMP 12/13 WEIR SECTION VERTICAL SCALE: 1 "=2HORIZONTAL SCALE 1 "=5' NOTE: REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. JOL 360 358 356 354 352 350 348 346 344 JOG 360 358 356 354 352 350 348 346 344 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 1+70 1+80 1+90 2+00 2+10 CROSS SECTION G-G' (BMP 12/13) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 DID I� I� II �I■❑■ ■I I� �I �I[IIW III roll oil DI�I�I�II�II■❑■■III I�I�I[II , � , ; �. ,'.: �I��_.�i�._ ��� �� . 18"DIAMETER CULVERT t CULVERT SEE NOTE 6 MIN. 8- 7.0' Y2" DIA. STEELBAR Y" THICK - STEEL PLATE D IN. C MIN. i L CIRCULAR STORMWATER MANAGEMENT 0 6" SO. MAX. RISER I.D. - - RISER O.D. 4, 1- 3'-0" DIA. 1 4" 1"--- CLASS A-3 CONCRETE TO BE BASIN I USED TO FILL SWM DRAINAGE STRUCTURE TO INVERT OF SIDE VIEW OUTLET PIPE. SWM DRAINAGE STRUCTURE 2" WIDE X'/y" THICK STEEL RING BOLTED TO RISER TYP. WOW RISER DIMENSION APPROX. I.D. O.D. A I B C D E SEGMENT WT. (LBS.) 36 44 42 1 6 1 13 18 40 22 82 NOTES: 1. COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER METAL MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. NOTES: 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR 1. A HINGED, LOCKABLE ACCESS DOOR SHALL BE PROVIDED ON TRASH RACK. STEP DETAILS SEE STANDARD ST-1. 2. ANTI -VORTEX PLATE IS TO BE USED WHEN SPECIFIED ON THE PLANS. COST OF 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK FURNISHING AND PLACING THE ANTI -VORTEX PLATE IS TO BE INCLUDED IN THE 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1" WIDE HORIZONTAL STRIPES AT 1' BID PRICE FOR THE STRUCTURE. INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. DETAIL: I2/I3 LEVEL 2 BIORETENTION 36 INCH VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK WATERTIGHT CAP 6' P.V.C. SCREW CAP ON TERMINAL END ON GRADE OF PIPE 6 P,V.C. NONPERFORATED /STANDPIPE Opp ��� �.�; OOOOOOOOO.00Opppppppp� , ■ r .N RECYCLED PLASTIC PIPE MAY BE SUBSTITUTED FOR PVC PIPE IF ALL CONVEYANCE AND ROUGHNESS CRITERIA ARE DEEMED ADEQUATE 1 DETAIL: PIPE CLEANOUT 11 NTS NOTES: 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH FLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER * SIDE WALLS MAY CONFORM TO THE SHAPE OF EXCAVATED TRENCH ** SHALL NOT BE LESS THAN 6" %2 (D + 2t) %2 D*NIP i t (thickness) = 3.0" %4 DOR&'**- DETAIL: CULVERT CONCRETE CRADLE NTS FLOTATION CALCULATIONS FOR RISER (I2/I3) GIVEN: WEIGHT OF WATER = 64.2o LBS/CU-FT WEIGHT OF CONCRETE=15o.00 LBS/CU-FT TOP INVERT OF RISER = 352.8 FT, NAVD88 INVERT OF 6" UNDERDRAIN = 348.3 FT, NAVD88 INVERT OF 18" CULVERT = 348.o FT, NAVD88 BOTTOM INVERT OF RISER = 345•o FT, NAVD88 HEIGHT OF RISER = 7.8 FT RISER INSIDE DIAMETER = 3.o FT WALL THICKNESS = 4 INCHES RISER INSIDE AREA = 7.07 SF RISER OUTER AREA =1o.56 SF RISER BASE: RISER BASE AREA =10.56 SF BASE DEPTH = 3.o FT RISER OPENINGS: WATER QUALTI•Y ORIFICE (3.5" DLAM.) = 0.07 SF UNDERDRAIN ORIFICE (6" DIAMETER) = 0.20 SF OUTFALL CULVERT (IS" DIAMETER) = 1.77 SF TOTAL AREA = 2.04 SF TOTAL VOLUME (AREA X 4") = o.68 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 50.7 CU-FT VOLUME OF BASE = 31.7 CU-FT TOTAL DISPLACED VOLUME = 126.72 CU-FT WEIGHT OF DISPLACED WATER = 5,139 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE =16.76 CU-FT VOLUME OF OPENINGS = 1.07 CU-FT TOTAL VOLUME OF RISER = 15.69 CU-FT WEIGHT OF RISER = 2,353 LBS WEIGHT OF BASE: VOLUME OF BASE = 31.7 CU-FT WEIGHT OF BASE = 4,752 LBS TOTAL COUNTERWEIGHT = 7,105 LBS FACTOR OF SAFETY =1.38 , � _ • ADHESIVEBOLIS W/FLAT WASHERS ••■ T ,, ; ' I LOCKABLE ACCESS "'D111■❑■�J: ■.I . . ICRETE TO BE SWM DRAINAGE STRUCTURE TO INVERT OF Y2" DIA. STEEL BAR Y" THICK - STEEL PLATE D MIN, p C MIN. CIRCULAR STORMWATER MANAGEMENT BASIN 0 { f� 6" SO. MAX. - RISER I.D. RISER O.D. 2" WIDE X %" THICK STEEL RING BOLTED TO RISER TYP. TYP. , � _ • ADHESIVEBOLIS W/FLAT WASHERS ••■ T ,, ; ' I LOCKABLE ACCESS "'D111■❑■�J: ■.I . . ICRETE TO BE SWM DRAINAGE STRUCTURE TO INVERT OF Y2" DIA. STEEL BAR Y" THICK - STEEL PLATE D MIN, p C MIN. CIRCULAR STORMWATER MANAGEMENT BASIN 0 { f� 6" SO. MAX. - RISER I.D. RISER O.D. 2" WIDE X %" THICK STEEL RING BOLTED TO RISER TYP. TYP. 25 37 92 49 SIDE VIEW OUTLET PIPE. SWM DRAINAGE STRUCTURE 84 100 94 12 RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 111W7,I_1ki ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. I IiilPLTH OF Dr �f v SCOTT C. BLOSSOM y Lac. No. 40287 O INNAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK I & J: PROFILE AND SECTIONS (2) NTS FILEPATH:C:\Users1H1111DropboAProjectsW05 RivannaNEWDesign and Analysis\CADW05_RivannaPH2_SVJM_REV2.dvglHiIIIApr 11, 2018 a: 17:181Layout: 11 Bmp 1213 (XS) NTS SWM-11 Ores 345.1 I SCALE: I INCH = 6o FEET O' 6o' 120' CONTOUR INTERVAL = 2 FT BMP 12/13 VICINITY MAP (SEE INSET) AUTOCAD FILE WILL BE SUPPLIED TO SELECTED CONTRACTOR CONTAINING GEOGRAPHIC COORDINATES OF ALL PROPOSED BMPS FOR LAYOUT, STAKING AND AS BUILT SURVEY. 240' SCALE: I INCH = 20 FEET 0' 20' 40' CONTOUR INTERVAL = 2 FT INSET - BIORETENTION 12/13 PLANTING PLAN M LEVEL 2 BIORETENTION 12 AND 13 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AA 13 ARONIA ARBUTIFOIA RED CHOKEBERRY #2 CONTAINER FAC #SP4 CONTAINERS SHALL BE 123 ANDROPOGON VIRGINICUS BROOMSEDGE BLUESTEM #SP4 CONTAINER FACU SPACED APPROXIMATELY 3 FEET ON CENTER. BN 3 BETULA NIGRA RIVER BIRCH #7 CONTAINER FACW 103 CONOCLINIUM COELESTINUM BLUE MIST FLOWER #SP4 CONTAINER FAC #2 AND #7 CONTAINERS SHALL BE LOCATED AS SHOWN ON CA 26 CORNUS AMOMUM SILKY DOGWOOD #2 CONTAINER FACW PLAN. :EV:'..,;. 71 ELYMUS VIRGINICUS VIRGINIA WILD RYE #SP4 CONTAINER FACW 26 EUPATORIUM PERFOLIATUM BONESET #SP4 CONTAINER FACW LB 6 LINDERA BENZOIN NORTHERN SPICEBUSH #2 CONTAINER FAC PO 3 PLATANUS OCCIDENTALIS SYCAMORE #7 CONTAINER FACW 112 PANICUM VIRGATUM SWITCH GRASS #SP4 CONTAINER FAC QM 3 QUERCUS MICHAUXII SWAMP CHESTNUT OAK #7 CONTAINER FACW '; .:�77 27 VERNONIA NOVEBORACENSIS NEW YORK IRONWEED #SP4 CONTAINER FACW VD 13 VIBURNUM DENTATUM ARROWWOOD VIBURNUM #2 CONTAINER FAC NOTE: DETAILED LANDSCAPE PLANTING DESIGN WILL BE INCLUDED WITH STAGE 4 PLAN SET. SOIL SPECIFICATION: AMENDED SOIL SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5%ORGANIC MATTER; AND HAVE A PHOSPHORUS CONTENT OF 7 TO 21 mglkg OR A P-INDEX OF 10 TO 30. (PER VIRGINIA DCR STORMWATER DESIGN SPECIFICATION NO.9) PERMANENT STABILIZATION SEED MIX (0.21 AC.) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES APPLY SEED AT RATE OF 200 LBS./AC. 90 FESTUCA ARUNDINACEA TALL FESCUE FACU SEED APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW 10 POA PRATENSE KENTUCKY BLUEGRASS FACU MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA SCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 KE ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. IIIII LTH op-7 �f v SCOTT C. BLOSSOM y Lac. No. 40287 O ��� �ZSSIONAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK I & J: PLANTING (2) FILEPATH:C:\Users\HiIBDropbox\Projects\005 RivannaNENADesign and Analysis\CAD=5_RivannaPH2_SWM_REW AMIH IIIApr 11, 2018 at 17:181Layoul: 12 Bmp 1213 Planting NOTE: ALL DISTURBED AREAS INCLUDING EMBANKMENT SLOPES SHALL BE HYDROMULCHED AT THE RATES SPECIFIED HEREIN. SWM - 12 STORMWATER MANAGEMENT CALCULATIONS LEVEL 2 WET SWALE J1 CALCULATIONS DRAINAGE AREA (ONSITE) = 2.82 ACRES DRAINAGE AREA (OFFSITE) = 3.07 ACRES TOTAL DRAINAGE AREA = 5.89 ACRES REQUIRED TREATMENT VOLUME (ONSITE) - 1.25 * 5,588 CIF 6,985 CIF REQUIRED TREATMENT VOLUME (OFFSITE) = 1.25 * 641 CIF = 801 OF TOTAL REQUIRED TREATMENT VOLUME = 7,786 CIE STORAGE PROVIDED = 9,863 CIE (AT & ABOVE NORMAL POOL 334.0 FT) SURFACE AREA REQUIRED (1-1) 5% OF CONTRIBUTING DRAINAGE AREA = 12,828 SF SURFACE AREA REQUIRED (1-2) 10% OF CONTRIBUTING DRAINAGE AREA = 25,557 SF SURFACE AREA AT NORMAL POOL = 7,522 SF (3%) SURFACE AREA AT TOP OF BERM = 16,165 SF (6.3%) LEVEL 2 WET SWALE J1 DIMENSIONS: PROPOSED LOW FLOW WEIR ELEVATION = 333.5 FT PROPOSED HIGH FLOW WEIR ELEVATION = 334.0 FT MAX WET STORAGE DEPTH = 1 FT (TYPICAL) (OFFLINE STORAGE) WEIR WIDTH = 10 FT WEIR LENGTH = 25 FT EMBANKMENT HEIGHT = 2 FT, ELEVATION = 336 FT MINIMUM EMBANKMENTTOP WIDTH = 5 FT MIN. CHANNEL SLOPE = 0.5% SIDE SLOPE = 3:1 LINING = VEGETATED WITH EC-2 MATTING OFF-SWALE STORAGE (POOLS) = 9,863 CIF LEVEL 2 WET SWALE J1 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 Q50 Q100 ON (HR) Cl Cl (Cl Cl Cl (Cl Cl PROPOSED 77.0 0.212 8.81 12.43 18.54 23.94 32.04 39.14 46.97 ROUTED 77.0 0.212 6.12 9.34 15.10 20.31 28.12 35.04 42.65 WSE 33398 WSE3 11 WSE3 29 WSE33941 WSE339.53 WSE330.72 WSE 33685 LEVEL 2 WET SWALE J2 CALCULATIONS: DRAINAGE AREA (ONSITE) = 2.59 ACRES DRAINAGE AREA (OFFSITE) = 1.90 ACRES TOTAL DRAINAGE AREA = 4.49 ACRES REQUIRED TREATMENT VOLUME (ONSITE) = 1.25 * 5,408 OF = 5,760 CIE REQUIRED TREATMENT VOLUME (OFFSITE) = 1.25 * 1,527 CIF = 1,909 CIE TOTAL REQUIRED TREATMENT VOLUME = 8,659 OF TOTAL STORAGE PROVIDED = 11,987 CIF (& ABOVE NORMAL POOL) LEVEL 2 WET SWALE J2 DIMENSIONS: PROPOSED LOW FLOW WEIR ELEVATION = 330.5 FT PROPOSED HIGH FLOW WEIR ELEVATION = 331.0 FT WET SWALE THALWEG = 330.5 - 330.0 FT MAX WET STORAGE DEPTH = 4 FT, ELEVATION 325 FT (FOREBAY) WEIR WIDTH = 12 FT WEIR LENGTH = 12 FT EMBANKMENT HEIGHT = 2 FT, ELEVATION = 332 FT MINIMUM EMBANKMENT TOP WIDTH = 6 FT MIN. CHANNEL SLOPE = 0.5% SIDE SLOPE = 31 HIGH FLOW LINING = 3-6 INCH ROUNDED RIVER COBBLE (18 INCH DEPTH) OFF-SWALE STORAGE (POOLS) = 11,987 OF LEVEL 2 WET SWALE J2 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 Q50 Q100 CN (HR) Cl (CFS) (Cl Cl (Cl (Cl ClPROPOSED 81.0 0.140 8.97 12.32 17.85 22.67 29.79 35.98 42.75 ROUTED 81.0 0.140 5.25 9.45 14.82 19.40 26.12 32.01 38.49 WSE330.99 WSE33111 WSE33125 WSE33135 10I/SE33149 WSE33159 ME33159 GRASSED CHANNELJ7 CALCULATIONS: DRAINAGE AREA = 0.73 ACRES FOREST/OPEN SPACE AREA = 0.10 ACRES MANAGED TURF AREA = 0.39 ACRES IMPERVIOUS AREA = 0.24 REQUIRED TREATMENT VOLUME = 1,139 OF SWALE LENGTH = 240 FEET BOTTOM WIDTH = 4 FEET 2H:1 V SIDE SLOPES ON CHANNEL SIDE 3H:1 V OR FLATTER ON RESIDENTIAL SIDE AVG. LONGITUDINAL SLOPE = 4.2% LINE CHANNEL WITH EC-3 MATTING WITH CLASS I RIPRAP OUTLET PROTECTION END TREATMENT PER DETAIL 7, SWM-19 (SEE SWM-14 FOR TYPICAL SECTION AND DESIGN COMPUTATIONS) LEVEL 1 BIORETENTION J5 CALCULATIONS: DRAINAGE AREA = 1.39 ACRES RUNOFF REDUCTION TREATMENT VOLUME = 3,296 OF EFFECTIVE STORAGE DEPTH = 1.4 FT REQUIRED SURFACE AREA = TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 2,354 SF LEVEL 1 BIORETENTION J5 DIMENSIONS: PROPOSED SURFACE AREA = 2,378 SF, ELEVATION 351.0 FT SOIL MEDIA DEPTH = 2 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 36 INCHES, ELEVATION = 352.0 FT OUTLET BARREL LENGTH = 50 FT, INV. US = 348.5 FT, INV. DS = 347 FT OUTLET BARREL DIAMETER = 18 INCHES WATER QUALITY ORIFICE DIAMETER = 3.5 INCHES, ELEVATION = 351.5 FT UNDERDRAIN DIAMETER = 5INCHES, INVERT ELEVATION = 348.5 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 2 FT, ELEVATION = 353 FT MINIMUM EMBANKMENT TOP WIDTH = 5 FT MINIMUM SIDE SLOPE = 3:1 (INTERNAL), 3:1 DOWNSTREAM; UPSLOPE RETAINING WALL OUTLET PROTECTION: GIVEN: 18 INCH PIPE OUTFALL 10-YR DISCHARGE (Q) = 8.26 CFS OUTFALLS TO GRASSY SLOPE A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 1 BIORETENTION J5 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 51NCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 8 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 10 FT LEVEL 1 BIORETENTION J5 HYDROLOGY SUMMARY Tc Q1 Q2 05 010 Q25 Q50 Q100 ON (HR) (Cl (Cl Cl Cl (Cl (Cl Cl PROPOSED 88.0 0.083 3.96 5.15 7.08 8.72 11.08 13.11 15.32 ROUTED 88.0 0.083 3.17 4.68 6.57 8.26 10.63 12.73 14.96 WSE 352.22 WSE 352 29 WSE 35237 WSE 35293 WSE 35251 WSE 3Ci2.55 WSE 3Ci'2.51 FILEPATH:C:\Users\HiIBDropboz\Projects\005 RivannaNENADesign and Analysis\CAM005_RivannaPH2_SWM _REV2.d"I lllApr 12, 2018 at 13:2711-al 13 SW W BIk Jeast / ♦♦��� BMP11 7� F6 #1 0.3 AC \ o x IXISTING SIREPM BUFFER I I' \\\ ICI JD1 w.E.+- NODE A jNII SEE ENERGY BALANCE CALCULATIONS PROVIDED ON MASTERPLAN SHEET SWM 4 FOR WATER QUANTITY D NOTE 12 AND 13 DO NOT ♦ i i DRAIN TO WET POND LEVEL II(11) _ BMP 12 -1 A rI- J /, / / 1 i '1/ i' ' FI ( BMP 1300 { _ u i AA _it I ref S � BMP J1 \ 1 1 •\ / I ) COMPLIANCE t II I �I� / _•`U II BLOCK r J(EAST) BMP JIf �a CA J2a 1.90 AC BLOCK J (EAST): BMP J1 AND J2 + ++ �e- 9JAAC \� \ \\ + +) ` SCALE: 1 INCH = 8o FEET o80' 160' 320' , III /' vOUTFALL vv\A CONTOUR INTERVAL = 2 FIT \ \ \ (4p BLOCK J (WEST): BMP J5 AND J77 SCALE: I INCH = 8o FEET 0' 8o' 16o' CONTOUR INTERVAL = 2 FT 320' DA J1a 1 I 3.07 AC 1 1 j 1 U// I I i I LEVEL 2 WET SWALES - LOW/HIGH FLOW DIVERSION (TREATED LANDSCAPE TIMBER) DOWNSTREAM OF FOREBAY - LOW FLOW DIRECTED TO WET SWALE (SEE PLANTING PLAN SHEET SWM-15) - HIGH FLOW DIRECTED TO BYPASS CHANNEL (LINED WITH 3-6 INCH ROUNDED RIVER COBBLE, MIN DEPTH 12 INCHES) - J2 TREATED TIMBER CHECK DAM AT 50 FT INTERVAL (SEE PROFILE FOR CREST ELEVATION) - J2 EQUIPPED WITH OFFLINE WETLAND POCKET STORAGE (SEE PLANTING PLAN SHEET SWM-15 FOR WETLAND PLANT PALETTE) i NOTE: SEE SHEET SWM-1.5 FOR PLANTING PLAN. ♦ I �� d /�' ' / ' / c BLOCK 05 A� 5 J(EAST) BLOCK '�C ♦♦ 010 J(WEST) - -., / 1 '. "«�-i' ��� I°ss .\ BMP J2 \ �® ♦� GRASSED SWALE, //` I D =•- -, 4' BOTTOM WIDTH, MI AVG.LONG. SLOPE=4.2% Y �I BMP J5 + (SEE SHEET SWM-1 4) OJ \ V DA J2b J7 III, +III, + +++ I + + I I \ Kill ♦% I o \9UTFALL a DAJ5 r I SEE DETAIL 7 SHEET \ '\ / 6WM-19 FOR END\ 1.39AC jj TREATMENT la - NOTE: PROPOSED RETAINING WALL ASSOCIATED WITH BMP J5 SHALL TIE INTO PROPOSED RETAINING WALL AT CULVERT CROSSING AND SHALL INCLUDE PEDESTRIAN RAILING (SEE CIVIL SITE PLANS AND RETAINING WALL DESIGN TO BE INCLUDED WITH BUILDING PERMIT APPLICATION). SEE SHEET SWM-15 FOR PLANTING PLAN. c LEGEND PROPOSED LIMITS ` OF DISTURBANCE SITE BENCHMARK PER ROUDABUSH ( r GALE AND ASSOC. SURVEY) EXISTING WETLANDS (PER KIRK HUGHES & ASSOC. yW.°W SURVEY) OEXISTING STREAM CHANNEL LIMITS �� (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING POND (PER KIRK HUGHES & ASSOC. SURVEY) OAPPROXIMATE EXISTING TREE LINE (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING ROAD � (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING FENCE (PER KIRK HUGHES & ASSOC. SURVEY) ®EXISTING BUILDING (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING POWER POLE o (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING SIGN °s (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING MANHOLE H' (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING CONTOURS (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING STREAM BUFFER (PER ALBEMARL.F. COUNTY) O PROPOSED BIORETENTION DSOIL FILTER ENGINEERED SOIL MEDIA PROPOSED OUTFALL PROTECTION PROPOSED CONTOURS �+ PROPOSED SWM BMP DRAINAGE AREA DIVIDES DA c3 PROPOSED SWM BMP 1 .38 AC DRAINAGE AREA LABELS OPROPOSED 6-INCH PVC UNDERDRAINS PROPOSED SAFETY BENCH ® OPROPOSED AQUATIC BENCH/WETLAND AREA OPROPOSED OPEN WATER PROPOSED COMPOST AMENDED SOILS RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 Q ISSUE REV # DATE DESCRIPTION 1 03.02.2018 PER COUNTY COMMENTS. 2 04.16.2018 PER COUNTY COMMENTS. PLTH OF Dr�f v SCOTT C. BLOSSOM y Lac. No. 40287 I 16,A0 �Il ��SSIONAL 0�� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER PLAN: BLOCK J (EAST & WEST) SWM -13 348 348 344 344 _ NOTCHED TREATED TIMBER DIVERSION LEVEL 2 WET SWALE (J EXISTING GRADE HIGH FLOW - 333.5 FT ELEV.1) 346 SURFACE AREA 346 342 LOW FLOW = 333.25 FT ELEV• 342 _ � CREST = 334.0 FT ELEV. LEVEL 2 WET SWALE (A) RIVANNA VILLAGE: PROPOSED GRADE � SURFACE AREA 344 344 340 340 STORMWATER PLAN TOP OF BERM I I I I 11• ELEV -336 o F P 342 PROPOSED \ 342 338 - \ _� - 2OYR 338 STABILIZATION \ EXISTINGGRADE WSE334.11FT 34-41 FT WWSE3334.85FT \� EDING \ too '� AMENDMENT 1 AND PHASE II 340 \III 340 336 OREBAY �' __. --_ -- 336 ALBEMARLE COUNTY, VIRGINIA IIIIII-III too-YR IIIII-III - ___ --- 338- \ PROPOSED GRADE 338 334 III- PROPOSED INFLOW SWALE 2YR --- --- - 334 _ - 2YRWSE=334.11FT \ W� 8 FT BOTTOM WIDTH, _ I _ 1oYR WSE=334.41 FT \ I 336 100YR WSE=334.85 FT 336 332 LINE WITH EC 3 MATTING HIGH FLOW SPILLWAY WEIR 332 - � � � � - CREST ELEV.FT, _ -_ LEV.= 'TiLO I -1 100-YR L--_ � L--_ � L- `�� Y )� Y ) - 6" CHECK DAMS TO REMAIN BOTTOM FT, - - 10-YR PROPOSED WET SWALE BOTTOM FROMEROSIONN 3:1 SIDE SLOPES 334- LOW FLOW 2-YK 334 330 - _ F:I.EV. 333.25 -> 333.0 = &SEDIMENT _ l- _I 330 II�� BOTTOM WIDTH = B FT - ELEV• �334.O FI'I LOW FLOW SPILLWAY WEIR - PROPOSED CLASS I RIP RAP� I- PROPOSED LEVEL SPREADER - g:1 SIDE SLOPES - I i i CREST ELEV. 333.5 FT, - -I 33 LOW FLOW CHANNEL TO BE LINE HIGH FLOW CHANNEL TO BE LINED 332 328 FOREBAY LINED WITH - TRANSITION 3-6 INCH - III GEOTEXTILE FABRIC-- ROUNDED RIVER COBBLE SLOPE = <1% III III -III -III BOTTOM WIDTH - 5 FI, - I 328 - I� --I I- WITH 1====1 I _ WIT 3LAIN I I I ( 2 MIN. DEPTH) (1.5 MIN. BE I I I I I I I I SIDE SLOPS WITH CLASS I RIPRAP 1 � ' COBBLE UNDERLAIN WITH CLASS I UNDERLAIN WITH CLASS I RIPRAP DER IN WITH CLASS I - - ME I I I3.I --- RIPRAP (MIN. DEPTH 12 INCHES) (MIN DEPTH 12 INCHES) . 330 326 330 r- 20 FT BOTTOM WIDTH 10 FT BOTTOM WIDTH -i 326 I 6INCH FLOW DEPTH 6INCH FLOW DEPTH - 0+00 0+10 0+20 0+30 0+40 0+50 o+6o 0+70 o+8o 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+6o 1+70 1+8o 1+90 2+00 2+10 2+20 2+30 2+40 2+50 2+60 2+70 2+80 2+90 3+00 3+10 3+20 3+30 3+40 3+50 3+6o SEEDED WITH WETLAND SEED MIX SEEDED WITH WETLAND SEED MIX =� 328 328 CROSS SECTION I -I' (BMP Jl) BICE 0+00 0+10 0+20 0+30 0+40 0+50 o+6o 0+70 o+8o 0+90 1+00 1+10 1+20 1+30 1+40 1+50 VERTICAL SCALE: 1"=4' HORIZONTAL SCALE 1"=20 CROSS SECTION H-H' (BMP Ji) Blossom Consulting and Engineering Inc. VERTICAL SCALE: 1"=4' HORIZONTAL SCALE 1"=20 1101 Professional Drive, Suite G Williamsburg, VA 23185 344 344 p:757-870-4825 342 342 342 342 PROPOSED STRUCTURAL FILL SEE NOTES SHEET 18 EXISTING 340 340 340GRADE TOPGFBERM 1340 NOTCHED TREATED TIMBER DIVERSION ELEV. 332.0 FT HIGH FLOW = 330.50 FT ELEV. 338 338 338 PROPOSED LOW FLOW = 330.25 Fr ELEV. 338 LEVEL 2 WET SWALE (J2) GRADE CREST = 331.00 FT ELEV. HIGH FLOW BYPASS SURFACE AREA CHANNEL (LINED WITH 3-6 TABILIZED INCH ROUNDED RIVER OUTFACE 336 336 336 COBBLE, 1 FT DEPTH) (CLASS I RNIP�; 336 EXISTING GRADE - LEVEL 2 WET SWALE (J2) DEPTH) HIGH FLOW BOTTOM SURFACEAREA 334 ELEV.=330.5FI 334 334 2YR WSE=331.11 FT IIIIII -III 334 2YR WSE=331.11 FT 1OYR WSE=331.35 FT - PROPOSED INFLOW SWAL 1ooYR WSE=331.69 FT _ WITH 8 FI'305� 3 - �o 332 1ooYRWWSE333369 FTFT � ✓ 332 332 _ SLOPES�� -III- oo_YR 332 (LONG. SLOPE-12.9%) - PROPOSED - LINE WITH EC-3 MATTING - ---- GRADE 16' 10' 1 . in _ __�_ 330 �l-n^TT�SEDSTABI ZATIO^: 330 330 III -III o 330 ,...".G A:.D",ATTING (SEE DETAILS I-3, SHEET \ 32$ _ _ _ _ - - - ---' ---' ---' 328 32$ PROPOSED CLASS I RIPRAP _ _ FOREBAY LINED WTTI-I- _ HIGH FLOW SPILLWAY WEIR CREST ELEV.=331.0 FT, 328 _ _ PROPOSED WET SWALE GEOTEXTILE FABRIC (2' MIN. DEPTH) 6' FROM CHECK DAMS TO REMAIN EROSION & SEDIMENT BO•FTOM WIDTH = I2 FT, _ 326 III BOTTOM WIDTH =16 FEET - 326 326 O i III CONTROL PLAN, TOP 3:1 SIDE SLOPES -III-III 326 KEY PLAN FLOW DEPTH BEFORE HIGH FLOW CHANNEL TO BE LINED -III -III -III- ELEV.=334•o FT - I I _III -III -. OVERTOPPING = 3INCH WITH 3{i ROUNDED RIVER COBBLE _ _ LOW FLOW SPILLWAY WEIR MAX PONDING DEPTH=IFT (MIN DEPTH 12 INCHES) _- PROPOSED 6-8INCHES OF _ - CREST ELEV. 330.5 FT, - 324 10FTBOTTOM WIDTH - _I I- _I I- - 324 324 TOPSOIL FOR PLANTING BOTTOM WIDTH =SFI,I III 324 6INCH FLOW DEPTH --- --- --- (SEE PLANTING PLAN, SHEET 15) 3:1 SIDE SLOPES SEEDED WITH WETLAND SEED MIX I I I I I I I I I I I I- 322 --- --- --- 322 322 322 0+00 0+10 0+20 0+30 0+40 0+50 o+6o 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 0+00 0+10 0+20 0+30 0+40 0+50 o+6o 0+70 o+8o 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+6o 1+70 i+8o 1+90 2+00 2+10 2+20 2+30 2+40 2+50 2+60 2+70 2+80 2+90 3+00 CROSS SECTION J-J' (BMP J2) CROSS SECTION K-K' (BMP J2) VERTICAL SCALE: 1"=4' HORIZONTAL SCALE 1"=20 VERTICAL SCALE: 1"=4' HORIZONTAL SCALE 1"=20 364 364 362 PROPOSED GRADE 362 LEVEL 1 BIORETENTION FILTER (J5) SURFACE AREA ISSUE 360 2YR WSE=352.29 Ff 360 36" RCP RISER (INSIDE DIA. 10YR WSE-352.43 FT WITH METAL TRASHRACK AND 100YR WSE=352.61 FT REV # DATE DESCRIPTION 35 ANTI -VORTEX PLATE 358 RIM ELEVATION=352.0 FT 3.5" ORIFICE @ ELEV.=351,.5 FT 337 1 03.02.2018 PER COUNTY COMMENTS. TOP OF BERM ELEV.=353.O FT BMP J'7: TYPICAL SECTION P F R11 E = 6.0 FT 2 04.16.2018 PER COUNTY COMMENTS. 35 356 URFACE ELEV. 351.0 FT 336 PILL WAY WEIR CREST " SHREDDED HARDWOOD ELEV.=352.5 FT, BOTTOM 364 354 - EXISTIN MULCH LAYER ON SURFACE 8' WIDTH = 10 FT 354 DIMENSIONS O O GRADE . CHAN TOP WIDTH = 16.0 FI'. 335 EE OE 3M ~ CAPACITY MAX. DEPTH = 2.0 FT. A EL 35 2 PROPOSE 352 362 16 0' E G CAPACITY - 250 CFS .0FT O O O O UNDERDRAIN \ 0 VELOCITY = 12 FT/S 334 CLEANOUT ° "y PROPOSEDSTRUCTURAL SLOPE=4-5% �\ I=1 I -III-III-III-III- - �� FILL SEE NOTES SHEET 18 360 LINING = EC-3 350 - III -I Tf�=1 f�=Tf�=1 f�=Tf�=1 f�= 350 III 1=1I1=1I1=1I1=1I1=1I1=1I I NOTE: SEE LANDSCAPE 333 III- 50 Ig•,RC\ PLANS PROVIDED UNDER 348 I P@2'S\ 348 358 SEPARATE COVER FOR O _= CIJ S PLANTING PLAN OF BMP J7. 332 - PROPOSED ENGBVEERE I SOIL MIX =2 FT) 3560 UN DERLAIN WITH GE TEXTILE FABRI 346 DEPT(DEMH 4-INCH P 346 5 10 15 20 0.F ABOVE CROWN OF UNDERDRAIN CROWN OF DISTANCE (IT.) 33�20 -15 -10 -5 0 5 10 15 20 PITH F Dry 344 6-INCH SCHD. 40 PERFORATE PROPOSED CONCRETE I PVC UNDERDRAIN STABILIZED OUTFALL 344 TYPICAL GRASS SWALE CROSS SECTION (BMP J7) CRADLE ENTIRE LENGTH - DETAIL: BMP J1 WEIR SECTION ITTOF CONDUIT (SEE DETAIL) (cI.ASSIRIPRAP,MIN. 12-INCH STONE SUMP I 2-FrDEPTH) 1 1-III I I I I VERTICAL SCALE: 1" = 4' HORIZONTAL SCALE: 1" = 5' - - VERTICAL SCALE: 7 "-2' HORIZONTAL SCALE 1 "-5' SCOTT C. BLOSSOM " _LL(OPEN GRADED)FFIF U y 342 342 Lic. No. 40287 0+00 0+10 0+20 0+30 0+40 0+50 o+6o o+17o o+8o o+I90 1+oo 1+10 1+20 1+30 1+40 1+50 �0 334 4qr� CROSS SECTION M-M' (BMP J5) P F R11IONAL VERTICAL SCALE: 1"=4' HORIZONTAL SCALE 1"=20 E = 2.0 FF 333 355 T P FB 354 = (z IN D ) 332 O 2- EE WI E A A EL . 331.0 Job No: 1005 Drawn By: BCE GE DTI XT LE Date: 12.04.2017 Checked By: scoff C. Blossom, P.E. 0. E WI E 331 353 AlELIEVA25Z5FT 1 0 0 o BLOCK J (EAST): PROFILE AND SECTIONS 0 0 0 330 352 0 0 0 O O O O S RIPRAP 329 351 32820 35020 -15 -10 -5 0 5 10 15 20 -15 -10 -5 0 5 10 15 20 DETAIL: BMP J5 WEIR SECTION NOTE: REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED DETAIL: BMP J2 WEIR SECTION "=2' "=5' SWM 14 VERTICAL SCALE: 1 HORIZONTAL SCALE 1 VERTICAL SCALE: 1 "=2' HORIZONTAL SCALE 1 "=5' SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. FILEPATH:C:\Users\HilkDropbox\Projects\005 RivannaNEVADesign and Analysis\CAD\005_RivannaPH2_SWIM _REV2.dvglHilllApr 72, 2018 a173:27ILayout: 14 Blk JeM (XS) a 3 RIVANNA VILLAGE: BMP J5 NOTE: PROPOSED RETAINING WALL ASSOCIATION WITH BMP J5 STO R M WATE R PLAN s r SHALL TIE INTO PROPOSED RETAINING WALL AT CULVERT CROSSING AND SHALL INCLUDE PEDESTRIAN RAILING (SEE `� i S'F MKy, \ I I I I �nrrr nrmr• rr • »r• ranr��r m� r R`90✓� j S �0 ' 95 `•J "off �� %/ / / r•.J / I qC ! PROPOSED MAINTENANCE / / + ACCESS / + / — i j a„ / 9osgcJ BMP J2 F I i � I t1 \• // I S,r` A M \ PROPOSED MAINTENANCE ` je y� x' '„ y / `1'\•\� Y/ � 11l C_ `,' ACCESS ',;�:+,,;c • N A 1 CO ( ' I qS ✓� 1 SCALE: I INCH = 3o FEET \ oe Y� �Y �Y \•\ \Y �Y �Y q I CONTOUR INTERVAL = 2 FT \ \ NOTE: SEE OVERALL SITE LANDSCAPING PLAN FOR INDIVIDUAL PLANTINGS WITHIN NATURAL DISPERSION AREA. N/ 0 +7- BMP J 7 ' o F 361 / g�O✓�26 .00 // //i///i/ � `Y SOT l `SS\ 60 JCE \ I V 367S V, SCALE: 1 INCH = 3o FEET 0' 20 40' 8o' aM'..��rsgviw CONTOUR INTERVAL = 2 FT LEVEL 1 BIORETENTION J5 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AS 4 ALNUS SERRULATA TAG ALDER #2 CONTAINER OBL #2 CONTAINERS SHALL BE LOCATED AS SHOWN AND CA 3 CORNUS AMOMUM SILKY DOGWOOD #2 CONTAINER FACW SPACED 10 FEET ON CENTER. CO 2 CEPHALANTHUS OCCIDENTALIS BUTTONBUSH #2 CONTAINER DEL LB 8 LINDERA BENZOIN NORTHERN SPICEBUSH #2 CONTAINER FAC SN 2 SALIX NIGRA BLACK WILLOW #2 CONTAINER OBL VIA 2 VIBURNUM NUDUM POSSUMHAW #2 CONTAINER DEL VD 3 VIBURNUM DENTATUM ARROWWOOD VIBURNUM #2 CONTAINER FAC LEVEL 1 BIORETENTION J5 STABILIZATION SEED MIX (4,902 S.F.) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES 1 AGROSTIS PERENNANS AUTUMN BENTGRASS SEED FACU APPLY SEED AT RATE OF DISTURBED D TO ANY DIAREAS NOT ALREADY STABILIZED. APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. 15 CHAMAECRISTA FASCICULATA PARTRIDGE PEA FACU 5 CHASMANTHIUM LATIFOLIUM RIVER OATS FACU 15 ELYMUS VIRGINICUS VIRGINIA WILD RYE FACW 1 EUPATORIUM PERFOLIATUM BONESET FACW 2 HELENIUM AUTUMNALE COMMON SNEEZEWEED FACW 5 PANICUM RIGIDULUM REDTOP PANIC GRASS FACW 5 PANICUM VIRGATUM SWITCH GRASS FAC 25 SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM FACU 5 SENNA MARILANDICA MARYLAND SENNA FAC 15 SORGHASTRUM NUTANS INDIAN GRASS FACU 5 TRIDENS FLAVUS I PURPLE TOP FACU 1 VERNONIA NOVEBORACENSIS I NEW YORK IRONWEED FACW AUTOCAD FILE WILL BE SUPPLIED TO SELECTED CONTRACTOR CONTAINING GEOGRAPHIC COORDINATES OF ALL PROPOSED BMPS FOR LAYOUT, STAKING AND AS BUILT SURVEY. LEVEL 2 WET SWALE J1 PLANT PALETTE: WETLAND AREAS LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES 125 ALISMA SUBCORDATUM WATER PLANTAIN OBL #SP4 CONTAINERS SHALL BE SPACED APPROXIMATELY 3 FEET ON CENTER. PLANTS 60 CAREX VULPINOIDEA FOX SEDGE OBL 65 CHELONE GLABRA TURTLE HEAD OBL SHALL BE INSTALLED FROM NORMAL POOL ELEVATION TO (12) TWELVE INCHES BELOW 65 HIBISCUS MOSCHEUTOS SWAMP ROSE -MALLOW OBL 85 JUNCUS EFFUSUS SOFT RUSH FACW NORMALPOOL. 80 LOBELIA CARDINALIS CARDINAL FLOWER FACW #SP4 CONTAINER 65 PELTANDRA VIRGINICA ARROW ARRUM DEL DISTRIBUTE PLANTS RANDOMLY AMONG SPECIES IN MINIMUM GROUPS OF 12 BY 100 SAGITTARIA LATIFOLIA DUCK POTATO OBL 100 SAURURUS CERNUUS LIZARD'S TAIL OBL SPECIES. LOCATE PLANTS ACCORDING TO INDICATOR STATUS. 95 SCHOENOPLECTUS TABERNAEMONTANI SOFT STEM BULRUSH DEL 75 SPARGANIUM AMERICANUM AMERICAN BUR -REED OBL NOTE: REFER TO LANDSCAPE AND CIVIL SITE PLANS FOR ADDITIONAL LANDSCAPE PLANTING DETAILS. LEVEL 2 WET SWALE J2 PLANT PALETTE: WETLAND AREAS LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES 125 ALISMA SUBCORDATUM WATER PLANTAIN OBL #SP4 CONTAINERS SHALL BE SPACED APPROXIMATELY 3 FEET ON CENTER. PLANTS 60 CAREX VULPINOIDEA FOX SEDGE OBL 65 CHELONE GLABRA TURTLE HEAD OBL SHALL BE INSTALLED FROM NORMAL POOL ELEVATION TO (12) TWELVE INCHES BELOW 65 HIBISCUS MOSCHEUTOS SWAMP ROSE -MALLOW OBL 85 JUNCUS EFFUSUS SOFT RUSH FACW NORMAL POOL. 80 LOBELIA CARDINALIS CARDINAL FLOWER #SP4 CONTAINER FACW 65 PELTANDRA VIRGINICA ARROW ARRUM OBL DISTRIBUTE PLANTS RANDOMLY AMONG SPECIES IN MINIMUM GROUPS OF 12 BY 100 SAGITTARIA LATIFOLIA DUCK POTATO OBL 100 SAURURUS CERNUUS LIZARD'S TAIL OBL SPECIES. LOCATE PLANTS ACCORDING TO INDICATOR STATUS. 95 SCHOENOPLECTUS TABERNAEMONTANI SOFT STEM BULRUSH OBL 75 SPARGANIUM AMERICANUM AMERICAN BUR -REED OBL NOTE: REFER TO LANDSCAPE AND CIVIL SITE PLANS FOR ADDITIONAL LANDSCAPE PLANTING DETAILS. PERMANENT STABILIZATION SEED MIX (J5=0.113 AC, J7=0.113 AC) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES APPLY SEED AT RATE OF 200 LBS./AC. 90 FESTUCA ARUNDINACEA TALL FESCUE FACU SEED APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW 10 POA PRATENSE KENTUCKY BLUEGRASS FACU MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA 13CE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. o��PLTH OF Dr.6f � x v SCOTT C. BLOSSOM y Lac. No. 40287 O ��� �ZSSIONAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK J (EAST & WEST): PLANTING SWM - 15 FILEPATH:C:\Users\HiIBDropbox\Projects\005 RivannaNENADesign and Analysis\CAD=5_RivannaPH2_SWM_ REV2.dvIglHiIllApr 11, 2018 at 17:1911-ayout: 16 Bilk Jeast PlanBng STORMWATER MANAGEMENT CALCULATIONS LEVEL 2 BIORETENTION H1 (PREVIOUSLY HS3b (WET SWALE)) CALCULATIONS: DRAINAGE AREA = 1.28 ACRES RUNOFF REDUCTION TREATMENT VOLUME = 2,592 OF EFFECTIVE STORAGE DEPTH = 1.65 FT REQUIRED SURFACE AREA = 1.25 TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 1,964 SF LEVEL 2 BIORETENTION H1 DIMENSIONS: PROPOSED SURFACE AREA = 2,225 SF, ELEVATION 356 FT SOIL MEDIA DEPTH = 3 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 35 INCHES, ELEVATION = 357 FT OUTLET BARREL LENGTH = 48 FT, INV US = 352.0 FT, INV. IDS = 350 FT OUTLET BARREL DIAMETER = 18 INCHES WATER QUALITY ORIFICE DIAMETER = 3.5 INCHES, ELEVATION = 356.5 FT UNDERDRAIN DIAMETER = 6 INCHES, INVERT ELEVATION = 352.5 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 4 FT, ELEVATION = 360 FT MINIMUM EMBANKMENT TOP WIDTH = 6 FT MINIMUM SIDE SLOPE = 31 OUTLET PROTECTION: GIVEN: 18 INCH PIPE OUTFALL 10-YR DISCHARGE (Q) = 7.02 CFS OUTFALLS TO GRASSY SLOPE A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 2 BIORETENTION H1 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 6 INCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 8 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 10 FT LEVEL 1 BIORETENTION J3 CALCULATIONS: DRAINAGE AREA = 0.78 ACRES RUNOFF REDUCTION TREATMENT VOLUME = 1,639 CIF EFFECTIVE STORAGE DEPTH = 1.4 FT REQUIRED SURFACE AREA = TREATMENT VOLUME / EFFECTIVE STORAGE DEPTH = 1,171 SF LEVEL 1 BIORETENTION J3 DIMENSIONS: PROPOSED SURFACE AREA = 2,102 SQ.FT., ELEVATION 352 FT SOIL MEDIA DEPTH = 2 FT, UNDERLAIN WITH 1 FT LAYER OF #57 GRAVEL OUTLET RISER DIAMETER = 35 INCHES, ELEVATION = 353 FT OUTLET BARREL LENGTH = 50 FT OUTLET BARREL DIAMETER = 18 INCHES, INV US = 349.5 FT, INV. DS = 349 FT WATER QUALITY ORIFICE DIAMETER = 3.5 INCHES, ELEVATION = 352.5 FT UNDERDRAIN DIAMETER = 6 INCHES, INVERT ELEVATION = 349.5 FT, ENCASED IN PEA GRAVEL EMBANKMENT HEIGHT = 2 FT, ELEVATION = 354 FT MINIMUM EMBANKMENT TOP WIDTH = 8 FT MINIMUM SIDE SLOPE = 4:1 (INTERNAL), 3:1 (DOWNSTREAM) OUTLET PROTECTION: GIVEN: 18 INCH PIPE OUTFALL 10-YR DISCHARGE (Q) = 4.22 CFS OUTFALLS TO GRASSY SLOPE A MINIMUM TAILWATER CONDITION IS ASSUMED USING PLATE 3.18-3 OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, LEVEL 1 BIORETENTION J3 OUTFALL DIMENSIONS: MINIMUM STONE DIAMETER = 6 INCHES (CLASS I RIPRAP) MINIMUM APRON LENGTH = 5 FT MINIMUM APRON END WIDTH = PIPE DIAMETER + MINIMUM APRON LENGTH = 6.5 FT SIMPLE DISCONNECTION J6 CALCULATIONS: DRAINAGE AREA = 0.57 ACRES FOREST/OPEN SPACE AREA = 0.16 ACRES MANAGED TURF AREA = 0.24 ACRES IMPERVIOUS AREA = 0.17 ACRES REQUIRED TREATMENT VOLUME = 779 OF GRAVELHEADERTRENCH LENGTH = 265 FT WIDTH = 2 FT DEPTH = 2 FT POROSITY = 0.4 STORAGE VOLUME = 424 CIF COMPOST AMENDED SOIL SURFACE AREA = 5,152 SF DEPTH = 1 FT POROSITY = 0.25 STORAGE VOLUME = 1,288 CIF TOTAL PROVIDED TREATMENT VOLUME = 1,712 OF 'TO BE PLACED UNDER A CONSERVATION EASEMENT. LEVEL 2 BIORETENTION H1 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 Q50 Q100 CN (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 85.4 0.083 3.20 4.28 6.04 7.54 9.73 11.62 13.67 ROUTED 85.4 0.083 1.90 3.48 5.53 7.02 9.15 10.97 12.95 WS W715 ME35723 WSE3573 WS W738 ME35746 WSE35752 WS W7M LEVEL 1 BIORETENTION J3 HYDROLOGY SUMMARY Tc Q1 Q2 Q5 Q10 Q25 Q50 Q100 CN (HR) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) (CFS) PROPOSED 85.5 0.083 2.04 2.70 3.77 4.69 6.02 7.17 8.41 ROUTED 86.5 0.083 0.19 1.41 3.08 4.22 5.50 6.71 7.91 WSE3 as WSE353.12 WSE353.21 WSE353.27 WSE35333 WSE353.37 WSE353.42 �fp yOAr'�o b8 a 3pip, v �9�,R n Inxei:I►1b7 PROPOSED LIMITS � OF DISTURBANCE OSITE BENCHMARK (PER ROUDABUSH, GALE AND ASSOC. SURVEY) EXISTING WETLANDS (PER KIRK HUGHES & ASSOC. yW.°W SURVEY) OEXISTING STREAM CHANNEL LIMITS (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING POND (PER KIRK HUGHES & ASSOC. SURVEY) APPROXIMATE EXISTING TREE LINE (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING ROAD � (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING FENCE (PER KIRK HUGHES & ASSOC. SURVEY) ®EXISTING BUILDING (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING POWER POLE o (PER KIRK HUGHES & ASSOC. SURVEY) OEXISTING SIGN os (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING MANHOLE H' (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING CONTOURS (PER KIRK HUGHES & ASSOC. SURVEY) EXISTING STREAM BUFFER (PER ALBEMARL.F. COUNTY) 0 PROPOSED BIORETENTION FILTER ENGINEERED SOIL MEDIA PROPOSED OUTFALL PROTECTION PROPOSED CONTOURS �+ PROPOSED SWM BMP DRAINAGE AREA DIVIDES 9DA c3 PROPOSED SWM BMP 1 .38 AC DRAINAGE AREA LABELS OPROPOSED I INCH PVC UNDERDRAINS ® PROPOSED SAFETY BENCH OPROPOSED AQUATIC BENCH/WETLAND AREA OPROPOSED OPEN WATER ►ii:PROPOSED COMPOST AMENDED SOILS SCALE: I INCH = 6o FEET O' 60' 120' CONTOUR INTERVAL = 2 FT RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 VCV DI AAI ISSUE REV # I DATE I DESCRIPTION 1 1 1 03.02.2018 1 PER COUNTY COMMENTS. I TH OF Dr�f v SCOTT C. BLOSSOM y Lac. No. 40287 ADO �W� �ZSSIONAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER PLAN: BLOCK J (WEST) SWM - 16 FILEPATH:C:\Users\HiIBDropbox\Projects\005 RivannaNEWADesign and Analysis\CAM005_RivannaPH2_SWM_ REV2.dwgIHilllApr 11, 2018 at 17:1911-ayoul: 16 SWIJ3 Blk Jwest 366 LEVEL 2 BIORETENTION 6" RCP RISER (INSIDE DIA.) 366 FILTER(H1) WITH METAL TRASHRACK AND SURFACE AREA ANTI -VORTEX PLATE 364 RIM ELEVATION=357.o FT 364 3.5" ORIFICE @ ELEV. 356.5 FT 362 SURFACE ELEV.=356.0 FT TOP OF BERM 362 364 - 364 3" SHREDDED HARDWOO ELEV. 360.0 FT PROPOSED MULCH LAYER ON SURFACE 360 GRADE PILLWAY WEIR CREST 360 362 36" RCP RISER (INSIDE DIA.) 362 YR WSE-357.23 FT ELEV. 358.0 FT, BOTTOM PROPOSED GRADE LEVEL 1 BIORETENTION WITH METAL TRASHRACK AND 1oYR WSE=357.38 FT WIDTH = 5 FT FILTER (J3) RIMI VORT O 353.0 Fr too-YR WSE=357.58 FT SURFACE AREA 35 --- --- 358 360 3.5 " ORIFICE @ ELEV. 352.5 FT 360 w'S PROPOSED STRUCTURAL PROPOSED UNDERDRAIN p / "G FILL SEE NOTES SHEET 18 HARDWOOD MULCH 77 CLEANOUT (SEE DETAIL 2) 35 356 358 LAYER ON SURFACE 358 TOP OF BERM ELEV. 354.o FT 2YR WSE=353.12 FT PROPOSED ENGINEERS JOYRWSE=353.27Fr SPILLWAY WEIR CREST354 __ 354 356 \8' ELEV. 353.5 FT, BOTTOM356 SOIL MIX (DEPTH=3FT) - - I=1 1=1 = - G J/ 00-YR WSE=353.42' III=III III=III=III= PROPOSED VDOT \ WIDTH =10 FT \ \ ES-1(18") EXISTIN SURFAC \ 42 , i8" *PROPOSED 352 354 GRADE ELEV. 352 O FT 354 352 EXISTING GRADE \ •yQ wy PROPOSED STRUCTURAL PROPOSE FILL SEE NOTES SHEET 18350 q-INCH DEPTH PEA GRAVEL LAYER ` UNDERDRAIN 350 352 CLEANOUT IIIIIIIII\ PROPOSED VDOT352 ABOVE CROWN OF UNDERDRAIN - LU--LU-IN-LU-I \ ES-1(18") 6-INCH SCHD. 40 PERFORATED PROPOSED ENGINEERS III= =III=III=III= 28'-18" RCP @ 0.5%348 348 350 \ 350 PVC UNDERDRAIN IRETE SOIL MIX (DEPTH=2 FT) IIIIIIIIIIII - Ili - -CRADLE ENTIRE LENGTH I _ 12-INCH STONE SUMP T OFCONDUIT (SEE DETAIL) II - - 346 -346 348 III�7348 OPEN GRADED) TABILIZED OUTFALL 4-INCH DEPTH PEA GRAVEL LAYER CLASSIRIPRAP MIN. - ( , ABOVE CROWN OF UNDERDRAIN5-FT CONCRETE-IIIIIIIII-III 2-FT DEPTH) _I -III IIII 344 IIIIIIIII BUOYANCY CONTROL 344 346 6-INCH SCHPVC UNDERDRAIN PROPOSED CONCRETE 346 _ IIIIIIIIIIIIIIIIIIIII-III -III- LENGTH =III=III TABILIZED OUTFACE - IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII-III-� IIIIIII 12-INCH STONE SUMP- GFCO DSEEDEZAIL) (GLASSIRIPRAP,MIN. 342 342 344 III -III- (OPEN GRADED) - III __ 2-FTDEPTHj 344 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 1+50 1+60 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 0+90 1+00 1+10 1+20 1+30 1+40 CROSS SECTION N-N' (H1) CROSS SECTION L-L' (J3) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 NONE 1120='1\■■■■■■■■■■■■■■I loommonommommom .■■■■■■■■■■■■■l N414owl BROOM .Pill or Pill owl 16 ■■■■■■■■■■■\E NOUN HOMS NON■■■■■■■■■■■■►'rABwE'��v,11 BfflI001p !�iE9■g o Eggs NO i ■■■■■■■■■■■■■■■■■ ■■■■■I • • • ■ - H1 WEIR SECTION VERTICAL SCALE: 1 "=21HORIZONTAL SEE NOTE 18"DIAMETER CULVERT t CULVERT i. M1►1 7.0' 000 355 3 FT 0- EE WI DE - 354 � 3 353 352 SI P FTMIN, E 351 D ERLAIN WITH 0 EXTILE F 350 10 15 20 -20 -15 -10 -5 0 5 DETAIL: BMP J3 WEIR SECTION VERTICAL SCALE: 1 "=2HORIZONTAL SCALE 1 "=5' h8" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8 PLACES -EQUALLY SPACED ON AN "E" DIA. B.C. %" DIA. STEEL BAR 1/z" THICK - STEEL PLATE D MIN. I C MIN. g" CIRCULAR 6" SO. MAX. STORMWATER RISER I.D. MANAGEMENT RISER O.D. 4„ 3'-0" DIA. 4• CLASS A-3 CONCRETE TO BE BASIN USED TO FILL SWM DRAINAGE STRUCTURE TO INVERT OF SIDE VIEW OUTLET PIPE. SWM DRAINAGE STRUCTURE LOCKABLE ACCESS DOOR W/HINGE SEE NOTE 1 2" WIDE X Y4" THICK STEEL RING BOLTED TO RISER TYP. TYP. 4 RISER M1►1 7.0' 000 355 3 FT 0- EE WI DE - 354 � 3 353 352 SI P FTMIN, E 351 D ERLAIN WITH 0 EXTILE F 350 10 15 20 -20 -15 -10 -5 0 5 DETAIL: BMP J3 WEIR SECTION VERTICAL SCALE: 1 "=2HORIZONTAL SCALE 1 "=5' h8" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8 PLACES -EQUALLY SPACED ON AN "E" DIA. B.C. %" DIA. STEEL BAR 1/z" THICK - STEEL PLATE D MIN. I C MIN. g" CIRCULAR 6" SO. MAX. STORMWATER RISER I.D. MANAGEMENT RISER O.D. 4„ 3'-0" DIA. 4• CLASS A-3 CONCRETE TO BE BASIN USED TO FILL SWM DRAINAGE STRUCTURE TO INVERT OF SIDE VIEW OUTLET PIPE. SWM DRAINAGE STRUCTURE LOCKABLE ACCESS DOOR W/HINGE SEE NOTE 1 2" WIDE X Y4" THICK STEEL RING BOLTED TO RISER TYP. TYP. 4 RISER DIMENSION APPROX. I.D. O.D. A B C D E SEGMENT WT. (LBS.) 36 44 42 6 13 18 40 22 82 NOTES: METAL 1. COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. NOTES: 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR 1. A HINGED, LOCKABLE ACCESS DOOR SHALL BE PROVIDED ON TRASH RACK STEP DETAILS SEE STANDARD ST-1. 2. ANTI -VORTEX PLATE IS TO BE USED WHEN SPECIFIED ON THE PLANS. COST OF 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. FURNISHING AND PLACING THE ANTI -VORTEX PLATE IS TO BE INCLUDED IN THE 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1" WIDE HORIZONTAL STRIPES AT 1' BID PRICE FOR THE STRUCTURE. INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. I DETAIL: Hi AND J3 LEVEL 2 BIORETENTION 36 INCH VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK WATERTIGHT CAP 6' P.V.C. SCREW CAP ON TERMINAL END ON GRADE OF PIPE 6 P,V.C. NONPERFORATED /STANDPIPE n n n n I ■ LANUtHUHAIIN RECYCLED PLASTIC PIPE MAY BE SUBSTITUTED FOR PVC PIPE IF ALL CONVEYANCE AND ROUGHNESS CRITERIA ARE DEEMED ADEQUATE DETAIL: PIPE CLEANOUT y7 NTS N■■■■■■ I . . '. ff■MMMMM SOMEONE • NOTES: 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH FLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER * SIDE WALLS MAY CONFORM TO THE SHAPE OF EXCAVATED TRENCH ** SHALL NOT BE LESS THAN 6" a. %2 (D + 2t) - 12" 1/12 D=21,*-11I RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II 360 360 ALBEMARLE COUNTY, VIRGINIA 358 358 PROPOSED GRADE PROPOSED EC-2 MATTING 356 AND STABILIZATION SEEDING 356 354 PROPOSED 354 STRUCTURAL FILL CONSERVATION 352 EA EMENTAREA 352 SIMPLE 350 ISCONNECTIO 350 348 EXISTING-? GRADE 348 ' 346 -11 - I -X2' GRAVEL.III DLaPHRAM III_ I I 1346 Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G _ _III-IIII Williamsburg, VA 23185 344 344 p: 757-870-4825 0+00 0+10 0+20 0+30 0+40 0+50 0+60 0+70 0+80 CROSS SECTION P-P' (J6) VERTICAL SCALE: 1 "=4' HORIZONTAL SCALE 1 "=20 t (thickness) = 3.0" I %4 DOR6"** DETAIL: CULVERT CONCRETE CRADLE NOTE: REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. NTS FLOTATION CALCULATIONS FOR RISER BASE (Hi & J3) GIVEN: WEIGHT OF WATER = 64.2o LBS/CU-FT WEIGHT OF CONCRETE = 150.00 LBS/CU-FT HEIGHT OF RISER = 7.0 FT RISER INSIDE DIAMETER = 3.0 FT WALL THICKNESS = 4 INCHES RISER INSIDE AREA = 7.07 SF RISER OUTER AREA = 10.56 SF RISER FOOTPRINT = 3.49 SF RISER BASE: RISER BASE AREA = 10.56 SF BASE DEPTH = 5.0 FT RISER OPENINGS: UNDERDRAIN ORIFICE (6" DIAMETER) = 0.20 SF OUTFALL CULVERT (30" OUTER DIAMETER) = 4.91 SF TOTAL AREA = 5.11 SF TOTAL VOLUME (AREA X 4") = 1.70 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 73.92 CU-FT VOLUME OF BASE = 52.8o CU-FT TOTAL DISPLACED VOLUME = 126.72 CU-FT WEIGHT OF DISPLACED WATER = 8,135 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE = 24.43 CU-FT VOLUME OF OPENINGS = 1.7o CU-FT TOTAL VOLUME OF RISER = 22.73 CU-FT WEIGHT OF RISER = 3410 LBS WEIGHT OF BASE: VOLUME OF BASE = 52.80 CU-FT WEIGHT OF BASE = 7,92o LBS TOTAL DOWNWARD WEIGHT =11,33o LBS FACTOR OF SAFETY = 1.39 13:11I7,I_1ki ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. oePLTB OF Dr.6f � x v SCOTT C. BLOSSOM y Lac. No. 40287 O INNAL E���� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK J (WEST): PROFILE AND SECTIONS NTS FILEPATH:C:\Ummr HilMropboalProjectsW05 RivannaNEWADesign and Analysis\CAD1005_RivannaPH2_SWM _REV2.dwglHiIIIApr 11, 2018 at 17:1911-ayout: 17 Bilk Jwest (XS) SWM - 17 l / BLOCK J (WEST): BMP J3 LEVEL 1 BIORETENTION J3 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AA 5 ARONIA ARBUTIFOIA RED CHOKEBERRY #2 CONTAINER FAC #2 CONTAINERS SHALL BE CA 5 CORNUS AMOMUM SILKY DOGWOOD #2 CONTAINER FACW LOCATED AS SHOWN AND SPACED 10 FEET ON CENTER. LB 5 UNDERA BENZOIN NORTHERN SPICEBUSH #2 CONTAINER FAC VD 5 VIBURNUM DENTATUM ARROWWOOD VIBURNUM #2 CONTAINER FAC LEVEL 1 BIORETENTION STABILIZATION SEED MIX (J3 - 2,102 S.F. AND H1 - 2,226 SF) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES 1 AGROSTIS PERENNANS AUTUMN BENTGRASS SEED FACU APPLY SEED AT RATE OF DI C. TO ANY DSTTURBURB ED AREAS NOT ALREADY STABILIZED. APPLY HYDROMULCH AT 1200 LBS./AC. OR STRAW MULCH AT 2 TONS/AC. INCORPORATE SEASONAL NURSE CROP IN ACCORDANCE WITH DATES SHOWN. 15 CHAMAECRISTA FASCICULATA PARTRIDGE PEA FACU 5 CHASMANTHIUM LATIFOLIUM RIVER OATS FACU 15 ELYMUS VIRGINICUS VIRGINIA WILD RYE FACW 1 EUPATORIUM PERFOLIATUM BONESET FACW 2 HELENIUM AUTUMNALE COMMON SNEEZEWEED FACW 5 PANICUM RIGIDULUM REDTOP PANIC GRASS FACW 5 PANICUM VIRGATUM SWITCH GRASS FAC 25 SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM FACU 5 SENNA MARILANDICA MARYLAND SENNA FAC 15 SORGHASTRUM NUTANS INDIAN GRASS FACU 5 TRIDENS FLAVUS PURPLE TOP FACU 1 VERNONIA NOVEBORACENSIS NEW YORK IRONWEED FACW PERMANENT STABILIZATION SEED MIX (J6=0.092 AC, Hi =0.279 AC, J3=0.376 AC) LEGEND MIX % BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES APPLY SEED AT RATE OF 200 LBS./AC. i i i i i i i 90 FESTUCA ARUNDINACEA TALL FESCUE FACU i APPLY HYDROMULCH AT 1200 i i i i i i i SEED LBS./AC. OR STRAW MULCH AT 2 TONS/AC. INCORPORATE SEASONAL i i i i i i i i 10 POA PRATENSE KENTUCKY BLUEGRASS FACU NURSE CROP IN ACCORDANCE WITH DATES SHOWN. SCALE: 1 INCH = 20 FEET 0' 20' 40' CONTOUR INTERVAL = 2 FT 7 -Z BLOCK (WEST): BMP Hi SCALE: 1 INCH = 20 FEET 0' 20' 40' CONTOUR INTERVAL = 2 FT LEVEL 2 BIORIETENTION H1 PLANT PALETTE LEGEND QUANTITY BOTANICAL NAME COMMON NAME SPECIFICATION INDICATOR (EMP) NOTES AS 4 ALNUS SERRULATA TAG ALDER #2 CONTAINER OBL #2 CONTAINERS SHALL BE LOCATED AS SHOWN. DISTRIBUTE PLANTS RANDOMLY AMONG SPECIES. LOCATE PLANTS ACCORDING TO INDICATOR STATUS. CO 3 CEPHALANTHUS OCCIDENTALIS BUTTONBUSH OBL CA 5 CORNUS AMOMUM SILKY DOGWOOD FACW LB 3 LINDERA BENZOIN NORTHERN SPICEBUSH FAC SIN 4 SALIX NIGRA BLACK WILLOW OBL VD 5 VIBURNUM DENTATUM ARROWWOOD VIBURNUM FAC VN 3 VIBURNUM NUDUM POSSUMHAW OBL `BLOCK J (WEST): BMP J6 SCALE: 1 INCH = 3o FEET RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BICE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 124w7: ISSUE IREV # I DATE I DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. PLTH pF Dr�f v SCOTT C. BLOSSOM y Lac. No. 40287 O ��� �ZSSIONAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. BLOCK J (WEST): PLANTING AUTOCAD FILE WILL BE SUPPLIED TO SELECTED CONTRACTOR CONTAINING GEOGRAPHIC COORDINATES OF ALL PROPOSED BMPS FOR LAYOUT, STARING AND AS BUILT SURVEY. FILEPATH:C:\Users\HiIBDropboz\Projects\005 RivannaNENADesign and Analysis\CAD=5_RivannaPH2_SWM_ REV2.d"111illlApr 11, 2018 at 17:2011-ayout: 18 Blk Jw st (Planting) o' 30' 6o' CONTOUR INTERVAL = 2 FT 120' SWM - 18 TOP OF SEDIMENT TRAP SURROUNDING GRADE (3:1 OR GENTLER SLOPE) SEDIMENT TRAP CONVERSION SEQUENCE: 1. GRADE SEDIMENT TRAP. O BIORETENTION FILTER BED ELEVATION TEMPORARY SEDIMENT TRAP BED ELEVATION O PVC SCREW CAP ON GRADE STABILIZE SLOPE BEFORE EXCAVATING NATIVE SOIL PVC NON -PERFORATED TO BIORETENTION FILTER STANDPIPE FLOOR ELEVATION GEOTEXTILE FABRIC :� SURROUNDING:'•�:�':��::�::::�::�: ':��:':'•�:�':':��:�: '.:�:�.� �:::':�:'. URROUNDING '•'.'' .. .. .. .. .... .. .':'. GRADE GRADE (3:1 OR FILTER SURFACE BIOFILTER SIDESLOPE EXCAVATION 1:1 OR GENTLER WATERTIGHT CAP ON TERMINAL NATIVE END F PIPE PERFORATED P.V.C. SOIL UNDERDRAIN (MAX. 12" DEPTH (TYP.) 10 ET SPACING) EXCAVATE SEDIMENT TRAP 12" #57 6' NON -PERFORATED TO PROPOSED ELEVATION STONE (TYP.) P.V.C. PIPE TO PROPOSED OUTFALL LOCATION SEDIMENT TRAP CONVERSION SEQUENCE: SEDIMENT TRAP CONVERSION SEQUENCE: 2. AFTER THE CONTRIBUTING AREA IS STABILIZED, EXCAVATE THE 3. PROVIDE A 12 INCH LAYER OF VDOT #57 STONE (TYP.). INSTALL SEDIMENT TRAP TO AN ELEVATION CORRESPONDING TO THE UNDERDRAIN NETWORK WITH A MAXIMUM OF 10-FOOT SPACING BIORETENTION FILTER FLOOR ELEVATION, AND DISPOSE OF BETWEEN UNDERDRAIN BRANCHES AND NEST 3-INCHES WITHIN EXCAVATED SOIL. THE #57 STONE LAYER ENSURING THAT PERFORATED PIPES WITH A WATERTIGHT CAP ON TERMINAL END ARE USED FOR UNDERDRAIN BRANCHES AND NON -PERFORATED PIPES ARE USED FOR PRIMARY UNDERDRAIN PIPE WITHIN 5 FT OF MANHOLE. INSTALL NON -PERFORATED CLEANOUT PIPE PER DETAIL. 6' PEA GRAVEL (#7 O 3-INCHES SHREDDED O STONE) OVERLAYING rHARDWOOD MULCH PROPOSED PONDING DEPTH UNDERDRAIN NETWORK F VEGETATION (SEE rVARIES (6-12" TYP.) 1MFPR�\l O' MAX. 6" DEPTH FILTER FABRIC AT 1=1 I1=1I1=1I1= ' (TYP,) TOP OF PEA GRAVEL OVER UNDERDRAIN ONLY (EXTEND 1-1 .5' SEDIMENT TRAP CONVERSION SEQUENCE: EACH SIDE) 5. INSTALL BIOFILTER SOIL MEDIA (AS SPECIFIED IN DESIGN PLANS) ENSURING THAT ABOVE SPECIFICATIONS ARE OBSERVED. SEDIMENT TRAP CONVERSION SEQUENCE: LIGHTLY TAMP BIORETENTION FILTER SOIL 4. PROVIDE PEA GRAVEL OVERLAYING UNDERDRAIN NETWORK MEDIA. ONCE BIORETENTION FILTER SOIL AND INSTALL FILTER FABRIC 1-1 .5 FEET ON TOP OF PEA GRAVEL MEDIA IS INSTALLED, INSTALL A 3-INCH LAYER ON EITHER SIDE OF THE UNDERDRAIN PIPE. OF SHREDDED HARDWOOD MULCH OVERLYING THE BIORETENTION FILTER SOIL MEDIA. DETAIL: SEDIMENT TRAP TO BIOFILTER CONVERSION SEQUENCE NTS SEDIMENT TRAP CONVERSION SEQUENCE: 6. SEED AND PLANT BIORETENTION FILTER SURFACE AREA ACCORDING TO THE PROVIDED PLANTING PLAN. GENERAL NOTES: 1) CONSTRUCTION OF THE BIORETENTION FILTERS SHALL NOT BE FINISHED UNTIL THE CONTRIBUTING DRAINAGE AREAS HAVE BEEN STABILIZED AND APPROVED BY THE COUNTY. UPON WHICH, THE BASINS SHALL FIRST BE CLEANED AND BROUGHT TO DESIGN GRADE. 2) CONTRACTOR SHALL CONTACT THE COUNTY INSPECTOR AND ENGINEER 24 HOURS PRIOR TO BACKFILLING THE BIORETENTION FILTERS, AND REQUEST AN INSPECTION AND APPROVAL OF THE UNDER -DRAIN INSTALLATION AND THE SOIL MIX. 1j T311TEE DIA ASHER 8DIA0" MIN.L PIN 11 G4VGE STEEL S1,•✓%STARE STAKE STAPLE PIN 1. 1/4 TRIANGLE SURVEY STAKE - MINIMUM 10' IN LENGTH. PLACEMENT OF THE STAKE ACROSS THE FLOW OF WATER IS THOUGHT TO PROVIDE A'PINBALL EFFECT" TO HELP SLOW THE VELOCITY, 2. 11 GAUGE STEEL - MINIMUM 1- WIDE BY v IN LENGTH STEEL STAPLE - 2'xe' STAPLE MAY BE REQUIRED IN CERTAIN SOIL CONDITIONS. 3.STEEL PINS -i - DIAMETER STEEL PIN BY 18' IN LENGTH WITH 2' DIAMETER WASHER ON TOP. (SEE ILLUSTRATION) DETAIL: SOIL MATTING ANCHORS TABLE 3.19-D REQUIREMENTS FOR FILTER FABRIC USED WITH RIPRAP Physical Properly Test Method ReQuirements Equivalent Corps of Engineers Equal or greater than Opening Size CWp 2215-77 U.S. No. 50 sieve Tensile Strength• VTM-52 30 lbs./linear in. @ 20%A (maximum) (minimum) Puncture Strength ASTM D751• 80 lbs. (minimum) Tension testing machine with ring clamp, steel ball replaced with 5/16 diameter solid steel cylinder with hemispherical tip centered within the ring clamp. Seams shall be equal in strength to basic material. Additional fabric material or non -corrosive steel wire may be incorporated into the fabric to increase overall strength. Sour: VDOT Road and Bridge Specifications NOTES: 1. FILTER FABRIC PER VESCH STANDARDS AND SPECIFICATIONS SHALL UNDERLAY ALL PROPOSED RIP RAP STABILIZATION AND OUTFALL PROTECTION. 2. RIP RAP SLOPE PROTECTION TO BE KEYED IN AT TEH TOE AS DEPICTED ON VESCH DETAIL THIS SHEET AND SHALL BE INSTALLED ALONG SLOPES ADJACENT TO STREAM CHANNELS AS DEPECTED IN PLAN VIEW ON DESIGN SHEETS. 3. CONCRETE END WALLS TO BE INSTALLED AT OUTFALLS AS SHOWN ON DESIGN SHEETS, MEETING STANDARDS AND SPECIFICATIONS PER VDOT DRAINAGE MANUAL, CURRENT EDITION. uuuuu W W m ■HUHUHUHUHUHuu uuuuuuul WHUHUoHUHUWUuHm 0000m ON SHALLOW SLOPES, STRIPS OF NETTING PROTECTIVE COVERINGS MAY BE APPLIED ACROSS THE SLOPE. BERM WHERE THERE IS A BERM AT THE TOP OF THE SLOPE, BRING THE MATERIAL OVER THE BERM AND ANCHOR IT BEHIND THE BERM. 74Aft ON STEEP SLOPES, APPLY PROTECTIVE COVERING PARALLEL TO THE DIRECTION OF FLOW AND ANCHOR SECURELY. ANCHOR SLOT @� p.'.. NOTES APPROXIMATELY 200 STAPLES REQUIRED PER 100 SQ. VDS. OF MATERIAL ROLL. ANCHOR SLOTS, JUNCTION SLOTS & CHECK SLOTS TO BE BURIED 5 TO 12', 12' MAX. 4:1 OR FLATTER & MAX. STEEPER THAN 4.1 JUNCTION SLOT EDGE AND END JOINTS I I I I I I I I TO BE SNUGLY ABUTTED CHECK SLOT (JUTE MESH WILL HAVE I TERMINAL FOLD STAPLED LAP JOINT IN I I LIEU OF EDGE JOINT) I LAP JOINT 2' MIN. (JUTE MESH ONLY) I I I I I TAMP FIRMLY ANCHOR SLOT I � 5' MAX. 4:1 OR FLATTER 3' MAX. STEEPER THAN 4:1 I 6'T012' - I I I I I I I I I I I I I I RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA (CHECK SLOT I I I I V' O 2^ I I I I [TAMP CHECK SLOT I I I II I I I FIRMLY - _t VAR. VAR. 1�1 H 6 TO 12 6"T08"MIN. PLAN VIEW 4 ' ""J�JJW STAPLING DIAGRAM BRING MATERIAL DOWN TO A LEVEL AREA BEFORE 4„,:, •.,.'+: n; TERMINATING THE INSTALLATION. TURN THE END UNDER 4' AND STAPLE AT 12' INTERVALS. •' a ^•. f STAPLE FORMED FROM N0.11 STEEL WIRE CHECK SLOTS AT MIN. 50' C-C INTERVALS; BICE 12 8"STAPLE MIN. LENGTH FOR SANDY SOIL. NOT REQ.'D WITH ALL IN DITCHES, APPLY PROTECTIVE COVERING PARALLEL TO THE DIRECTION OF FLOW. USE CHECK SLOTS AS REQUIRED. AVOID JOINING MATERIAL IN THE CENTER OF THE DITCH IF AT ALL POSSIBLE. DETAIL: E & S CONTROL BLANKET INSTALLATION OP PIPE/PUMP DISCHARGE CLASS I RIP RAP APRON PLAN VIEW L a ;1 FILTER CLOTH KEY IN 6'-9', RECOMMENDED FOR ENTIRE PERIMETER SECTION A -A NOTES' 1. APRON LINING MAY BE RIPRAP, GROUTED RIPRAP, GABION BASKET, OR CONCRETE. 2. La IS THE LENGTH OF THE RIPRAP APRON AS CALCULATED USING PLATES 3.18-3 AND 18-4. 3. d = 1.5 TIMES THE MAXIMUM STONE DIAMETER, BUT NOT LESS THAN 6 INCHES. 4. LEVEL SPREADER TRENCH TO BE INSTALLED PARALLEL TO CONTOUR AND TO MATCH THE PROPOSED GRADE. TOP LIP ELEVATION TO BE UNIFORM TO WITHIN 1 ". 5 DETAIL: OUTFALL PROTECTION 19 NTS TOE REQUIREMENTS FOR BANK STABILIZA TION FILTER CLOTH UNDERLINER (PREFERRED) GRANULAR FILTER Source: Adapted from VDOT Drainage Manual PROPOSED LOT SLOPE 24" X 24" GRAVEL DIAPHRAGM (VDOT #57 STONE) Plate 3,19.1 JUNCTION SLOT TAMP FIRMLY 12" 2' T 6'TO 12' DETAIL: E & S CONTROL STAPLING DETAIL CONSERVATION EASEMENT AREA SEE CIVIL DESIGN - PLANS AND CROSS SECTIONS FOR SLOPE RANGE ROUGHEN SLOPE, TOPSOIL, SEED, STABILIZE, AND LANDSCAPE PER PLAN. GEOTEXTILE FABRIC DETAIL: GRAVEL HEADER TRENCH EW-2PC DETAIL A W I � A PLAN SHAPE t0 BE BEVELED MORTAR BEVELED II� TERMINAL FOLD rTAMP FIRMLY PLAN VIEW -INFLOW PIPE ORSWALE 7� ---2'WIDTH INIS PROFILE VIEW INFLOW PIPE OR SWALE LASS I RIPRAP PROTECTION (2' MIN. DEPTH) I `LEVEL SPREADER = I_I I f TRENCH (PEA GRAVEL, #57 OR #1TTONE) LEVELSPREADER__'/ j TRENCH (PEA GRAVEL, PROPOSED #57 OR #1 STONE) BIOFILTER NOTE: LEVEL SPREADER TRENCH TO BE INSTALLED PARALLEL TO CONTOUR AND TO MATCH THE PROPOSED GRADE. TOP LIP ELEVATION TO BE UNIFORM TO WITHIN 1". INSTALL AT ALL OUTFALLS INTO LEVEL 2 BIORETENTION FACILITIES. n DETAIL: TYPICAL GRAVEL LEVEL SPREADER NOTESr L CONCRETE TO BE 40M PSI 1,11I COMPRESSIVE STRENGTH. 2. T PIPE IS E6NG WILL BE ADJUSTED 00AB ESKEWLED. uP TO 3. REINFORCING STEEL N ACCORDANCE WITH ASTM A-6t5 "REINFORCING BARS,. WL $ PER G 3 NAK SPACING 30- 4. PIPE OPENINGS N PRECAST DRAINAGE UNITS SHALL NOT EXCEED 4 INCHES AT ANY GWEN POINT BETWEEN THE PIPE AND THE PRECASTU14T. 5. DDENSIONS SHOWN ARE MINWN. ACTUAL MEASUREMENTS NAY VARY WITH mHuFACTIXER•S TOLERANCES. COTE INSERTS 6, IN NO CASE SHALL TOP OF ENDWALL PROTRUDE ABOVE FILL 8 ." LNG WLTS SLOPE. DITCH SLOPE. OR SMULDER- 7. HEADWALL TO BE BEVELED N ALL AREAS EXCEPT WHERE A CONFLICT WITH NvER7 OR WNGWALL OCCUR. B� BEVEL EDGE AS REOLVED ON THE HEADWALL AT THE INLET END OF THE CULVERT ONEW THE FLOW ENTERS THE CULVERT), 9. HEADWALL AT THE OUTLET END OF THE CULVERT MAY BE „ EITHER SOUITE EDGE OR BEVEL EDGE. \ IT Zi' CHALFFR NAY BE PROVIDED ON ALL DBMS AT IIAWUFACTUREArS OPTION DETAIL B DIMENSIONS D H W L O b H 4 SLOPE 2-1 SLOPE 42.1 5'-6" 6'-31 6'-T/i' 8•_C' O'-4Ys' 0'-S/f 4B" 6'-0" V-10" T-6" W-lo" O'-5" 0'-4" 54.. WIS.. T-5" e'-P/i' Ir-0" v-Ole v-4Yi W 7'-0- L'-0- B'-3" t2'-A+i v-N/!' 0'-S" W. 7'•7- 6'-aY" Iv-}/" 13'-y/- v-7" v-511- 72" R'-2" a'-31/r" 1T-0" 14'-9/i " v-7" v-9/i 84" W-3" W'-4" 12'-BYZ" 16'-9" 0'-7" 90" 9'-11" it•_1" 13--7" E:_ v-7" v 96" 1v-]• N'-1!• 14'-6" tq-1- v-]• O'-SYA" SEE DETAIL A- y6..r, i4 BARS o 6" EACH WAY, EACH FACE W4 EACH 0 d' EACH WAY, EACH FACE MIN M ■ENE■ ■���N■ L No n ��■ �����l NTS - -- ------ - - 1 „- oT CONCRETE INSERTS JSECTION SEE DETAIL B FRONT ELEVATION GROUT WINGS AAL ENDWALL TO BASE SECTIONS a 'Y'r LAD BOLTS A -A NtEXJr ENDWALL FOR PIPE CULVERTS IF 3EN REREFFERENCERENCE RCAPRECAST ROM AND BRIDGE 9TA/DARnS 42" - 96" CIRCULAR PIPE VIRGINIA DEPAR7LCNT OF TRANSPORTATION 105 302 s1EET 1 aF I REVISION DATE pI Dg Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 13�7,I_1� ISSUE REV # DATE DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. 4�$PLTH OF Dr.66 x v SCOTT C. BLOSSOM y Lac. No. 40287 W� IIIo �INNAL 'i � Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER DETAILS FILEPATH:C:\Uwmr HilRDropboXlProjectsW05 RivannaNEWDasign and AnalyslslCADW05_RivannaPH2_SWM_REWAMIKIllApr 11, 2018 at 17:201Layoul: 19 Stonn Details SWM - 19 ALBEMARLE COUNTY FINAL PLAN GENERAL NOTES GENERAL CONSTRUCTION NOTES 1. PRIOR TO ANY CONSTRUCTION WITHIN ANY EXISTING PUBLIC RIGHT-OF-WAY, INCLUDING CONNECTION TO ANY EXISTING ROAD, A PERMIT SHALL BE OBTAINED FROM THE VIRGINIA DEPARTMENT OF TRANSPORTATION (VDOT). THIS PLAN AS DRAWN MAY NOT ACCURATELY REFLECT THE REQUIREMENTS OF THE PERMIT. WHERE ANY DISCREPANCIES OCCUR THE REQUIREMENTS OF THE PERMIT SHALL GOVERN. 2. ALL MATERIALS AND CONSTRUCTION METHODS SHALL CONFORM TO CURRENT SPECIFICATIONS AND STANDARDS OF VDOT UNLESS OTHERWISE NOTED. 3. EROSION AND SILTATION CONTROL MEASURES SHALL BE PROVIDED IN ACCORDANCE WITH THE APPROVED EROSION CONTROL PLAN AND SHALL BE INSTALLED PRIOR TO ANY CLEARING, GRADING OR OTHER CONSTRUCTION. 4. ALL SLOPES AND DISTURBED AREAS ARE TO BE FERTILIZED, SEEDED AND MULCHED. 5. THE MAXIMUM ALLOWABLE SLOPE IS 2:1 (HORIZONTALMERTICAL). WHERE REASONABLY OBTAINABLE, LESSER SLOPES OF 3:1 OR BETTER ARE TO BE ACHIEVED. 6. PAVED, RIP -RAP OR STABILIZATION MAT LINED DITCH MAY BE REQUIRED WHEN IN THE OPINION OF THE COUNTY ENGINEER, OR DESIGNEE, IT IS DEEMED NECESSARY IN ORDER TO STABILIZE A DRAINAGE CHANNEL. 7. ALL TRAFFIC CONTROL SIGNS SHALL CONFORM WITH THE VIRGINIA MANUAL FOR UNIFORM TRAFFIC CONTROL DEVICES. 8. UNLESS OTHERWISE NOTED ALL CONCRETE PIPE SHALL BE REINFORCED CONCRETE PIPE - CLASS III. 9. ALL EXCAVATION FOR UNDERGROUND PIPE INSTALLATION MUST COMPLY WITH OSHA STANDARDS FOR THE CONSTRUCTION INDUSTRY (29 CFR PART 1926). GENERAL CONSTRUCTION NOTES FOR STREETS (THIS LIST IS IN ADDITION TO THE GENERAL CONSTRUCTION NOTES) 1. CONSTRUCTION INSPECTION OF ALL PROPOSED ROADS WITHIN THE DEVELOPMENT WILL BE MADE BY THE COUNTY. THE CONTRACTOR MUST NOTIFY THE DEPARTMENT OF COMMUNITY DEVELOPMENT (296- 5832) 48 HOURS IN ADVANCE OF THE START OF CONSTRUCTION. 2. UPON COMPLETION OF FINE GRADING AND PREPARATION OF THE ROADBED SUBGRADE, THE CONTRACTOR SHALL HAVE CBR TESTS PERFORMED ON THE SUBGRADE SOIL. THREE (3) COPIES OF THE TEST RESULTS SHALL BE SUBMITTED TO THE COUNTY. IF A SUBGRADE SOIL CBR OF 10 OR GREATER IS NOT OBTAINABLE, A REVISED PAVEMENT DESIGN SHALL BE MADE BY THE DESIGN ENGINEER AND SUBMITTED WITH THE TEST RESULTS FOR APPROVAL. 3. SURFACE DRAINAGE AND PIPE DISCHARGE MUST BE RETAINED WITHIN THE PUBLIC RIGHT-OF-WAY OR WITHIN EASEMENTS PRIOR TO ACCEPTANCE BY THE COUNTY. ALL DRAINAGE OUTFALL EASEMENTS ARE TO BE EXTENDED TO A BOUNDARY LINE OR A NATURAL WATERCOURSE. 4. GUARDRAIL LOCATIONS ARE APPROXIMATE. EXACT LENGTH, LOCATION AND APPROPRIATE END TREATMENTS WILL BE FIELD VERIFIED AT THE TIME OF CONSTRUCTION. ADDITIONAL GUARDRAIL MAY BE REQUIRED AT LOCATIONS NOT SHOWN WHEN, IN THE OPINION OF THE COUNTY ENGINEER, OR DESIGNEE, IT IS DEEMED NECESSARY. WHEN GUARDRAIL IS REQUIRED, IT SHALL BE INSTALLED FOUR (4) FEET OFFSET FROM THE EDGE OF PAVEMENT TO THE FACE OF GUARDRAIL, AND ROADWAY SHOULDER WIDTHS SHALL BE INCREASED TO SEVEN (7) FEET. 5. WHERE URBAN CROSS SECTIONS ARE INSTALLED, ALL RESIDENTIAL DRIVEWAY ENTRANCES SHALL CONFORM TO VDOT CG-9(A, B OR C). 6. WHERE RURAL CROSS SECTIONS ARE INSTALLED, ALL RESIDENTIAL DRIVEWAY ENTRANCES SHALL CONFORM TO VDOT STANDARD PE-1. 7. COMPLIANCE WITH THE MINIMUM PAVEMENT WIDTH, SHOULDER WIDTH AND DITCH SECTIONS, AS SHOWN ON THE TYPICAL PAVEMENT SECTION DETAIL, SHALL BE STRICTLY ADHERED TO. 8. ROAD PLAN APPROVAL FOR SUBDIVISIONS IS SUBJECT TO FINAL SUBDIVISION PLAT VALIDATION. SHOULD THE FINAL PLAT FOR THIS PROJECT EXPIRE PRIOR TO SIGNING AND RECORDATION, THEN APPROVAL OF THESE PLANS SHALL BE NULL AND VOID. 9. ALL SIGNS OR OTHER REGULATORY DEVICES SHALL CONFORM WITH THE VIRGINIA MANUAL FOR UNIFORM TRAFFIC CONTROL DEVICES AND THE ALBEMARLE COUNTY ROAD NAMING AND PROPERTY NUMBERING ORDINANCE AND MANUAL. 10. TRAFFIC CONTROL OR OTHER REGULATORY SIGNS OR BARRICADES SHALL BE INSTALLED BY THE DEVELOPER WHEN, IN THE OPINION OF THE COUNTY ENGINEER, OR DESIGNEE, THEY ARE DEEMED NECESSARY IN ORDER TO PROVIDE SAFE AND CONVENIENT ACCESS. 11. THE SPEED LIMITS TO BE POSTED ON SPEED LIMIT SIGNS ARE 5 MPH BELOW THE DESIGN SPEED, OR AS DETERMINED BY VDOT FOR PUBLIC ROADS. 12. VDOT STANDARD CD-1 OR CD-2 CROSS -DRAINS UNDER TO BE INSTALLED UNDER THE SUBBASE MATERIAL AT ALL CUT AND FILL TRANSITIONS AND GRADE SAG POINTS AS SHOWN ON THE ROAD PROFILES. 13. A VIDEO CAMERA INSPECTION IS REQUIRED FOR ALL STORM SEWERS AND CULVERTS THAT ARE DEEMED INACCESSIBLE TO VDOT OR COUNTY INSPECTIONS. THE VIDEO INSPECTION SHALL BE CONDUCTED IN ACCORDANCE WITH VDOTS VIDEO CAMERA INSPECTION PROCEDURE AND WITH A VDOT OR COUNTY INSPECTOR PRESENT. EMBANKMENT EXCAVATION AND COMPACTION REQUIREMENTS: 1. COMPACTION TESTS, USING THE MODIFIED PROCTOR METHODOLOGY (ASTM D 1557) SHALL BE COMPLETED AT A MINIMUM OF 1 TEST PER 5,000 SQUARE FEET OF EACH LIFT OF FILL. STRUCTURAL FILL SHALL BE COMPACTED AS SPECIFIED ON SHEET 20 AND PER GEOTECHNICAL RECOMMENDATIONS PROVIDED BY VIOLA ENGINEERING, MEETING 95% MAXIMUM DRY DENSITY WITHIN 2% OF OPTIMUM MOISTURE CONTENT. 2. ALL TRENCH EXCAVATION SHALL HAVE MINIMUM SIDE SLOPES OF 2:1. WET POND (11) PRINCIPAL SPILLWAY NOTES AND DETAILS: REINFORCED CONCRETE PIPE THE FOLLOWING CRITERIA APPLY: 1. MATERIALS: REINFORCED CONCRETE PIPE SHOULD HAVE BELL AND SINGULAR SPIGOT JOINTS WITH RUBBER GASKETS AND SHOULD EQUAL OR EXCEED ASTM DESIGNATION C-361. 2. BEDDING: ALL REINFORCED CONCRETE PIPE CONDUITS SHOULD BE LAID IN A CONCRETE BEDDING FOR THEIR ENTIRE LENGTH. THIS BEDDING SHOULD CONSIST OF HIGH SLUMP CONCRETE PLACED UNDER THE PIPE AND UP THE SIDES OF THE PIPE AT LEAST 25% OF ITS OUTSIDE DIAMETER, AND PREFERABLY TO THE SPRING LINE, WITH A MINIMUM THICKNESS OF 3 INCHES, OR AS SHOWN ON THE DRAWINGS. 3. LAYING PIPE: BELL AND SPIGOT PIPE SHOULD BE PLACED WITH THE BELL END UPSTREAM. JOINTS SHOULD BE MADE PER RECOMMENDATIONS FROM THE MANUFACTURER. AFTER THE JOINTS ARE SEALED FOR THE ENTIRE RUN OF PIPE, THE BEDDING SHOULD BE PLACED SO THAT ALL SPACES UNDER THE PIPE ARE FILLED CARE SHOULD BE TAKEN TO PREVENT ANY DEVIATION FROM THE ORIGINAL LINE AND GRADE OF THE PIPE. 4. BACKFILL: ALL BACKFILL MATERIAL AND PLACEMENT SHOULD CONFORM TO STRUCTURE BACKFILL SPECIFICATIONS IN APPENDIX A, EARTHEN EMBANKMENT. STRUCTURE AND CONDUIT BACKFILL: BACKFILL THAT IS BESIDE PIPES OR STRUCTURES SHOULD BE OF THE SAME TYPE AND QUALITY AS SPECIFIED FOR THE ADJOINING FILL MATERIAL. THE FILL SHOULD BE PLACED IN HORIZONTAL LAYERS NOT TO EXCEED 4 INCHES IN THICKNESS AND COMPACTED BY HAND TAMPERS OR OTHER MANUALLY DIRECTED COMPACTION EQUIPMENT. THE MATERIAL SHOULD COMPLETELY FILL ALL SPACES UNDER AND BESIDE THE PIPE. DURING THE BACKFILLING OPERATION, EQUIPMENT SHOULD NOT BE DRIVEN CLOSER THAN 4 FEET, AS MEASURED HORIZONTALLY, TO ANY PART OF A STRUCTURE. ALSO, EQUIPMENT SHOULD NEVER BE DRIVEN OVER ANY PART OF A STRUCTURE OR PIPE, UNLESS COMPACTED FILL HAS BEEN PLACED TO A DEPTH SPECIFIED BY THE STRUCTURAL LIVE LOAD CAPACITY OF THE STRUCTURE OR PIPE IN ORDER TO ADEQUATELY DISTRIBUTE THE LOAD. el��ld�_��iZiI��1i�L�1Ci7���Ci�93i7i�Li�9[i ► _ ► ■ � ►y� 71�Id���iZi7����i - _ ► � 1. THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE -CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. 2. ALL EROSION AND SEDIMENT CONTROL MEASURES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. 3. ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING. 4. A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES. 5. PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF -SITE BORROW OR WASTE AREAS), THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY. 6. THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN APPROVING AUTHORITY. 7. ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELOPMENT UNTIL FINAL STABILIZATION IS ACHIEVED. 8. DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING DEVICE. 9. THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER EACH RUNOFF PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. 10. ALL FILL MATERIAL TO BE TAKEN FROM AN APPROVED, DESIGNATED BORROW AREA. 11. ALL WASTE MATERIALS SHALL BE TAKEN TO AN APPROVED WASTE AREA. EARTH FILL SHALL BE INERT MATERIALS ONLY, FREE OF ROOTS, STUMPS, WOOD, RUBBISH, AND OTHER DEBRIS. 12. BORROW OR WASTE AREAS ARE TO BE RECLAIMED WITHIN 7 DAYS OF COMPLETION PER ZONING ORDINANCE SECTION 5.1.28. 13. ALL INERT MATERIALS SHALL BE TRANSPORTED IN COMPLIANCE WITH SECTION 13-301 OF THE CODE OF ALBEMARLE. 14. BORROW, FILL OR WASTE ACTIVITY INVOLVING INDUSTRIAL -TYPE POWER EQUIPMENT SHALL BE LIMITED TO THE HOURS OF TOOAM TO 9:OOPM. 15. BORROW, FILL OR WASTE ACTIVITY SHALL BE CONDUCTED IN A SAFE MANNER THAN MAINTAINS LATERAL SUPPORT, OR ORDER TO MINIMIZE ANY HAZARD TO PERSONS, PHYSICAL DAMAGE TO ADJACENT LAND AND IMPROVEMENTS, AND DAMAGE TO ANY PUBLIC STREET BECAUSE OF SLIDES, SINKING, OR COLLAPSE. 16. THE DEVELOPER SHALL RESERVE THE RIGHT TO INSTALL, MAINTAIN, REMOVE OR CONVERT TO PERMANENT STORMWATER MANAGEMENT FACILITIES WHERE APPLICABLE ALL EROSION CONTROL MEASURES REQUIRED BY THIS PLAN REGARDLESS OF THE SALE OF ANY LOT, UNIT, BUILDING OR OTHER PORTION OF THE PROPERTY. 17. TEMPORARY STABILIZATION SHALL BE TEMPORARY SEEDING AND MULCHING. SEEDING IS TO BE AT 75 LBS/ACRE, AND IN THE MONTHS OF SEPTEMBER TO FEBRUARY TO CONSIST A 50/50 MIX OF ANNUAL RYEGRASS AND CEREAL WINTER RYE, OR IN MARCH AND APRIL TO CONSIST OF ANNUAL RYE, OR MAY THROUGH AUGUST TO CONSIST OF GERMAN MILLET. STRAW MULCH IS TO BE APPLIED AT 80LBS/100SF. ALTERNATIVES ARE SUBJECT TO APPROVED BY THE COUNTY EROSION CONTROL INSPECTOR. 18. PERMANENT STABILIZATION SHALL BE LIME AND FERTILIZER, PERMANENT SEEDING, AND MULCH. AGRICULTURAL GRADE LIMESTONE SHALL BE APPLIED AT 90LBS/1000SF, INCORPORATED INTO THE TOP 4-6 INCHES OF SOIL. FERTILIZER SHALL BE APPLIED AT 1000LBS/ACRE AND CONSIST OF A 10-20-10 NUTRIENT MIX. PERMANENT SEEDING SHALL BE APPLIED AT 180LBS/ACRE AND CONSIST OF 95% KENTUCKY 31 OR TALL FESCUE AND 0-5% PERENNIAL RYEGRASS OR KENTUCKY BLUEGRASS. STRAW MULCH IS TO BE APPLIED AT 80LBS/100SF. ALTERNATIVES ARE SUBJECT TO APPROVED BY THE COUNTY EROSION CONTROL INSPECTOR. 19. MAINTENANCE: ALL MEASURES ARE TO BE INSPECTED WEEKLY AND AFTER EACH RAINFALL. ANY DAMAGE OR CLOGGING TO STRUCTURAL MEASURES IS TO BE REPAIRED IMMEDIATELY. SILT TRAPS ARE TO BE CLEANED WHEN 50% OF THE WET STORAGE VOLUME IS FILLED WITH SEDIMENT. ALL SEEDED AREAS ARE TO BE RESEEDED WHEN NECESSARY TO ACHIEVE A GOOD STAND OF GRASS. SILT FENCE AND DIVERSION DIKES WHICH ARE COLLECTING SEDIMENT TO HALF THEIR HEIGHT MUST BE CLEANED AND REPAIRED IMMEDIATELY. 20. ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE REMOVED WITHIN 30 DAYS OF FINAL SITE STABILIZATION, WHEN MEASURES ARE NO LONGER NEEDED, SUBJECT TO APPROVAL BY THE COUNTY EROSION CONTROL INSPECTOR. GENERAL CONSTRUCTION NOTES FOR STORMWATER MANAGEMENT PLANS 1. ALL DAMS AND CONSTRUCTED FILL TO BE WITHIN 95% OF MAXIMUM DRY DENSITY AND 2% OF OPTIMUM MOISTURE CONTENT. ALL FILL MATERIAL TO BE APPROVED BY A GEOTECHNICAL ENGINEER. A GEOTECHNICAL ENGINEER IS TO BE PRESENT DURING CONSTRUCTION OF DAMS. 2. PIPE AND RISER JOINTS ARE TO BE WATERTIGHT WITHIN STORMWATER MANAGEMENT FACILITIES. 3. FOR TEMPORARY SEDIMENT TRAPS OR BASINS WHICH ARE TO BE CONVERTED TO PERMANENT STORMWATER MANAGEMENT FACILITIES; CONVERSION IS NOT TO TAKE PLACE UNTIL THE SITE IS STABILIZED, AND PERMISSION HAS BEEN OBTAINED FROM THE COUNTY EROSION CONTROL INSPECTOR. WET POND LEVEL 2 (BMP Ii): OPERATION AND MAINTENANCE OF PRINCIPAL SPILLWAY: 1. SPILLWAY STRUCTURES SHOULD BE CLEARED OF DEBRIS PERIODICALLY AND AFTER ANY SIGNIFICANT RAINFALL EVENT WHERE INSPECTION REVEALS A SIGNIFICANT BLOCKAGE. 2. DURING LOW WATER CONDITIONS, CONCRETE SPILLWAY STRUCTURES SHOULD BE INSPECTED TO DECIDE IF WATER IS PASSING THROUGH ANY JOINTS OR OTHER STRUCTURE CONTACTS AND TO IDENTIFY ANY CRACKS, SPALLING, BROKEN OR LOOSE SECTIONS. ANY CRACKED, SPALLED, BROKEN OR LOOSE SECTIONS SHOULD BE CLEANED AND REFILLED WITH AN APPROPRIATE CONCRETE PATCHING MATERIAL. A PROFESSIONAL ENGINEER SHOULD BE CONSULTED TO REPAIR EXTENSIVE LEAKAGE, SPALLS, OR FRACTURES. 3. OUTLET PROTECTION (STILLING BASIN) AND DISCHARGE CHANNELS SHOULD BE CLEARED OF BRUSH AT LEAST ONCE PER YEAR 4. TRACK RACKS AND LOCKING MECHANISMS SHOULD BE INSPECTED AND TESTED PERIODICALLY TO MAKE SURE THEY ARE INTACT AND OPERATIVE. 5. ALL SLUICE GATES (OR OTHER TYPES OF GATES OR VALVES USED TO DRAIN AN IMPOUNDMENT) SHOULD BE OPERATED PERIODICALLY TO ENSURE PROPER FUNCTION. THE GATE AND STEM SHOULD BE PERIODICALLY LUBRICATED AND ALL EXPOSED METAL SHOULD BE PAINTED TO PROTECT IT FROM CORROSION. 6. ANY REPAIRS MADE TO THE PRINCIPAL SPILLWAY (RISER OR BARREL) SHOULD BE REVIEWED BY A PROFESSIONAL ENINEER. VERTICAL TRENCHING TO EXPOSE THE BARREL SHOULD NOT BE ALLOWED UNDER ANY CIRCUMSTANCES. THE TRENCH SIDE SLOPES SHOULD BE STEPPED BACK AT A 2:1 SLOPE, MINIMUM. NOTE: CONTRACTOR SHALL COORDINATE WITH DESIGN ENGINEER FOR INSPECTION OF ALL SWM FACILITIES DURING: A. STAKEOUT B. TRENCH/PIT GRADING C. UNDERDRAIN/GRAVEL BED INSTALLATION D. ENGINEERED SOIL MEDIA PLACEMENT E. FINAL STABILIZATION AND PLANTING CONTRACTOR IS RESPONSIBLE FOR GIVING SUFFICIENT NOTICE TO ENGINEER PRIOR TO INSPECTION AND FOR PROVIDING DOCUMENTATION INCLUDING: A. PHOTOS B. MATERIALS TICKETS C. SOILS TESTING D. AS BUILT DRAWINGS DOCUMENTATION SHALL DEMONSTRATE PROPER WORKMANSHIP CONSISTENT WITH PLANS, SPECIFICATIONS, AND REFERENCE STANDARDS, TO THE SATISFACTION OF THE ENGINEER AND OWNERS. EXISTING STREAM CHANNEL ENTRANCE TO PROPOSED WET POND (BMP II): 1. CHANNEL SHALL SPILLOVER MODIFIED CROSS VANE (SEE DETAIL 1, THIS SHEET) INTO CLASS II RIPRAP POOL AND CHANNEL LEADING TO WET POND NORMAL POOL. 2. INSTALL SPLASH ROCK BELOW VANE CREST. 3. APPROXIMATE CREST ELEVATION = 343 FT• 4. APPROXIMATE VANE ARM ELEVATION = 344 FT•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z ELEVATION - 6 SLOPEVANE-OUT 3 SLOPEVANE-IC. a OUTER BANK / HEADER ROCKS J jL FOOTER ROCKS // ROCK SEAMS BETWEEN // iTIH I - HEADER AND FOOTER ROCKS y SHOULD NOT ALIGN WHEAD SILL SHALL BE KEYED IN MIN. q HEADER ROCKS FOOTER ROCKS SPLASH ROCKS SELECT STRUCTURES TIE ARMS TO Y. BANKFULLAND/OR INNER BERM ELEVATIONS INNER BANK / 4`t 4 BACKFILL BEHIND THE STRUCTURE WITH COMPACTED FILL AND TOP TO BE FINISHED O`aWITH ��DETAILS RBM MIX AS PER THE TYPICAL REM AND TYPICAL SECTIONS iii „0.w�'$�`LEAVE FABRIC EXPOSED FOR INSPECTION, CONTRACTOR TO TRIM EA/D�y/AFTERWHICH 4 B/ HEADER ROCKS CLASS IRIPRAP ARMORING BANKFULL SCOUR WIDTH ,P06L B c, CLASSIRIPRAP ARMORING �- OUTER L BRF BANK EXTEND R ARMORING $ FEEL' DOWNSNS TREE AM OF OUTER VANE ARM AS DEPICTED UNLESS OTHERWISE SHOWN IN PLAN SILL SIL4IIEBE 1 KEYED IN MIN. FEET NO GAPS BETWEE ROCKS / LVANE-OUT SCOUR POOL TO BE CONSTRUCTED DURING INSTALLATION OF STRUCTURE. SEE PLAN VIEW AND PROFILE FOR POOL SIZES NON -WOVEN GEOTEXTILE FABRIC FOOTER COMPACTED ROCKS FILL SECTION C-C' EADER ROCKS M FLOW LEAVE FABRIC EXPOSED FOR INSPECTION, AFTERWHICH CONTRACTOR TO TRIM SWATER SURFACE ELEVATION PROPOSED CHANNEL 4 THALWEG NUMBER OF SPLASH ROCKS IS_ WSECHON -III- COMPACTED REINFORCED DETERMINED BY WIDTH OFBED MIX OPEN SPACE IMMEDIATELY -DOWNSTREAM OF FOOTERIII - =BOULDER AND SIZE OF - - NON -WOVEN AVAILABLE MATERIAL. REFERTO FABRIC BOULDER SIZING TABLE FORGEOTEXTILE MINIMUM SPLASH ROCKC110N B-B' COMPACTED CLAY FILL DIMENSIONS t DETAIL: MODIFIED CROSS VANE z0 NTS (ADAPTED FROM ROSGIN, WILDLAND HYDROLOGY) STRUCTURE DETAIL IS NOT TO SCALE AND ILLUSTRATIVE. ACTUAL NUMBER OF BOULDERS DEPENDS ON STREAM SIZE, AND IS ESTIMATED AT 18-20 (PER COURSE) FOR THE STRUCTURE FACE AND ARMS (NOT INCLUDING SILLS) LEGEND RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 13W7,I_1ki ISSUE IREV # I DATE I DESCRIPTION 1 1 03.02.2018 1 PER COUNTY COMMENTS. H OF Dr�� � z v SCOTT C. BLOSSOM y Lac. No. 40287 o �W� ��sStONAL ����� Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER NOTES SWM - 20 FILEPATH:C:\UwmkHill0ropboAPmjectskOOS RivannaNEMDesign and AnalysislCADt005_RivannaPH2_SWM_REV2.dwgIHilllApr 11, 2018 at 17:201Layout: 20 Storm Notes RIVANNA VILLAGE: TYPICAL CONSTRUCTION SEQUENCE STORMWATER PLAN BLOCK J 1. CONVERSION OF EROSION AND SEDIMENT CONTROL PRACTICES TO STORMWATER MANAGEMENT STRUCTURES SHALL TAKE 9.STAGE 2 DIVERSION CHANNELS SHALL BE INSPECTED FOR SIGNS OF EROSION AND REPAIRED AS NECESSARY PRIOR TO THE ONLY STAGE STAGE SITE GRADING STABILIZED GROWTH. WET SWALE (BMP Jl AND AND STORMWATER WETLAND PLACE AFTER 1 AND 2 HAS BECOME PERMANENTLY BY VEGETATIVE CONVERSION OF SEDIMENT BASINS. J 2) AMENDMENT 1 AND PHASE II ADEQUACY OF VEGETATIVE GROWTH AND GRADING STABILIZATION WILL BE DETERMINED BY ENGINEER AND REPRESENTATIVE (BMP Ii)MAINTENANCE GUIDELINES ALBEMARLE COUNTY, VIRGINIA ALBEMARLE COUNTY STAFF PRIOR TO THE START OF CONVERSION ACTIVITIES. CONTRACTOR MAY ADJUST CONSTRUCTION 10. UPON STABILIZATION OF THE CONTRIBUTING WATERSHEDS, STAGE 2 SEDIMENT BASINS (BLOCK J EAST) SHALL BE CONVERTED SEQUENCE WITH APPROVAL FROM ENGINEER TO FACILITATE CONSISTENCY WITH MARKET DRIVEN DEVELOPMENT PLANS (I.E. INTO LEVEL 1 AND LEVEL 2 WET SWALES. BLOCK PHASING).. • THIS CONVERSIONS REQUIRES FILLING OF SEDIMENT TRAPS BELOW THE PROPOSED FINISHED ELEVATION OF THE PROPOSED WET SWALE BMPS, AND REMOVAL/RELOCATION OF INLET POINTS. 9.2. First Year Maintenance Operations BLOCK G •• SHIFT SILT FENCE DOWN SLOPE OF PROPOSED EXCAVATION AREAS AND ESTABLISH PERIMTER CONTROLS PRIOR TOT INITIATING CONVERSION SEQUENCE. Successful establishment of constructed wetland areas requires that the following tasks be 2.DIVERSION CHANNELS TO BE INSPECTED FOR SIGNS OF EROSION AND REPAIRED AS NECESSARY PRIOR TO THE CONVERSION • PRIOR TO SEDIMENT TRAP CONVERSION, TEMPORARY DIVERSION DIKES SHALL BE REMOVED, FILLED AND STABILZED WITH undertaken in the first two years: OF SEDIMENT BASINS IN BLOCK G SEED AND EC-2 MATTING. 3. STAGE 2 SEDIMENT BASINS SHALL BE CONVERTED INTO LEVEL 2 BIORETENTION CELLS (SEE TYPICAL CONVERSION SEQUENCE INSTALL STORMWATER INFRASTRUCTURE PRIOR TO REACHING FINAL WET SWALE GRADE, AND STABILIZE INFLOW FORE Initial Inspections. During the first 6 months following construction, the site should be inspected BAYS PRIOR TO REACHING FINAL GRADE. DETAIL). at least twice after storm events that exceed I/2 inch of rainfall. • UTILIZE TEMPORARY PUMP AROUND AND CLEAN WATER DIVERSION AS NEEDED TO MAINTAIN DRY WORKING AREA DURING • STAGE 2 SEDIMENT BASIN SHALL BE DRAINED PRIOR TO START OF CONVERSION ACTIVITIES. RATE OF RELEASE SHALL BE WET SWALE EXCAVATION. CONTRACTOR IS RESPONSIBLE FOR MAINTAINING A DRY WORKING AREA, AND SHALL PLAN Sot Reseeding. Inspectors should look for bare or eroding areas in the contributing drainage P g• p g g g CONTROLLED TO PREVENT FLOODING/EROSION OF DOWNSTREAM CHANNEL. DRAINED FLUID/MATERIAL SHALL BE FILTERED PUMPING OPERATIONS AND DE -WATERING TO FACILITATE CONSTRUCTION. AND CONTAINED IN A MANNER SUITABLE FOR PREVENTING DOWNSTREAM CONTAMINATION. area or around the wetland buffer, and make sure they are immediately stabilized with grass • EXISTING RISER AND BARREL STRUCTURE SHALL BE INSPECTED FOR DAMAGE OR CLOGGING AND REPAIRED OR CLEANED cover. 11. STAGE 2 SEDIMENT TRAPS IN BLOCK J WEST SHALL BE CONVERTED INTO LEVEL 2 BIORETENTION BMPS. AS NECESSARY. • EXISTING RIPRAP INLETS TO BE TAMPED AND COMPACTED TO FILL VOID SPACES. • SEDIMENT TRAPS SHALL BE DRAINED PRIOR TO START OF CONVERSION ACTIVITIES. DRAINED FLUID/MATERIAL SHALL BE Watering. Trees planted in the buffer and on wetland islands and peninsulas need watering • EXISTING SEDIMENT BASIN TO BE FILLED WITH COMPACTED FILL TO DESIGN ELEVATIONS AS SPECIFIED IN PROFILE AND FILTERED AND CONTAINED IN A MANNER SUITABLE FOR PREVENTING DOWNSTREAM CONTAMINATION. during the first growing season. In general, consider watering every three days for first month, CROSS SECTIONS. 0 DUE TO PROPOSED FILL ACTIVITIES ASSOCIATED WITH PARK STREET, AND REQUIRED CONSTRUCTION OF RETAINING WALL, and then weekly during the first growing season (April - October), depending on rainfall. _ Blossom Consulting and Engineering Inc. • THE 4 INCH DEWATERING ORIFICE OF RISER SHALL BE PATCHED OVER WITH GROUT. BIORETENTION FACILITIES WILL REQUIRE PHASED CONSTRUCTION, WITH THE SEDIMENT TRAPS BEING RAISED • A 6 INCH ORIFICE SHALL BE CUT INTO THE RISER FOR THE PROPOSED BIORETENTION CELL UNDERDRAIN. INCREMENTALLY PRIOR TO CONVERSION. Reinforcement Plantings. Regardless of the care taken during the initial planting of the wetland 1101 Professional Drive, Suite G • A #57 GRAVEL LAYER OF 1 FOOT DEPTH SHALL BE INSTALLED ABOVE THE COMPACTED FILL. •• DO NOT BRING BIORETENTION FACILITY TO FINAL GRADE UNTIL UPSTREAM WATERSHED IS STABILIZED AND RETAINING and buffer, it is probable that some areas will remain unvegetaled and some species will not Williamsburg, VA 23185 • A 6 INCH PERFORATED PVC UNDERDRAIN, ARRANGED IN A BRANCH PATTERN WITH 10 FOOT SPACING, SHALL BE INSTALLED WALLS ARE CONSTRUCTED. survive. Poor survival can result from many unforeseen factors, such as predation, poor quality P: 757-870-4825 ABOVE THE GRAVEL LAYER THEN OVERLAIN WITH PEA GRAVEL AND COVERED WITH GEOTEXTILE. THE FINISHED EXISTING WEIRS SHALL BE RAISED TO ADJUST TO SURROUNDING FILL GRADES AND MAINTAIN SEDIMENT CONTROL DURING plant stock, water level changes, drought. Thus, it is advisable to budget for an additional round UNDERDRAIN SYSTEM SHALL HAVE A 1-2% SLOPE TOWARDS THE RISER. PLACEMENT OF FILL. UPON REACHING FINAL ROUGH GRADE RIPRAP OF EXISTING WEIRS SHALL BE TAMPED AND of reinforcement planting after one or two growing seasons. Construction contracts should COMPACTED TO FILL VOID SPACES, THEN ADDITIONAL RIP RAP PLACED TO ESTABLISH PROPOSED BMP WEIR ELEVATIONS. O ED BM WEIR • A MINIMUM 3 FOOT LAYER OF AMENDED SOIL SHALL BE INSTALLED TO THE FINISHED SURFACE ELEVATION. AMENDED SOIL include a care and replacement warranty extending at least two growing seasons after initial . INSTALL UNDER DRAINS AND RISER ASSOCIATED WITH EACH BMP PRIOR TO INSTALLATION SOIL MEDIA. SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC MATTER; AND HAVE A PHOSPHORUS CONTENT OF planting, to selectively replant portions of the welland (hat fail to fill in or survive. SEE CONVERSION SEQUENCE DETAIL PROVIDED HEREIN. 7 TO OR P-INDEX 10 TO 30 AS SPECIFIED IN TEH VIRGINIA STORMWATER MANAGEMENT HANDBOOK STANDARDS NS FOR BMPS. . EXISTING SEDIMENT TRAPS TO BE FILLED WITH COMPACTED FILL THEN TOPPED WITH AN AMENDED SOIL LAYER OF 2-3 FOOT AND SPECIFICATIONS DEPTH TO FINISHED ELEVATIONS. AMENDED SOIL SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC 9.3. Inspections and Ongoing Maintenance 4. STAGE 2 DIVERSION CHANNELS SHALL BE FILLED, GRADED, AND STABILIZED WITH PERMANENT SEED. MATTER; AND HAVE A PHOSPHORUS CONTENT OF 7 TO 21 mg/kg OR A P-INDEX OF 10 TO 30. Ideally, maintenance of constructed wetlands should be driven by annual inspections that 5. STAGE 2 SEDIMENT TRAPS SHALL BE CONVERTED INTO LEVEL 2 BIORETENTION FACILITIES.. evaluate the condition and performance of the wetland, including the following: • SEDIMENT TRAP SHALL BE DRAINED PRIOR TO START OF CONVERSION ACTIVITIES. DRAINED FLUID/MATERIAL SHALL BE BLOCKS D, F AND H FILTERED AND CONTAINED IN A MANNER SUITABLE FOR PREVENTING DOWNSTREAM CONTAMINATION. 12. SEDIMENT BASIN CS2 SHALL REMAIN IN PLACE UNTIL BLOCKS D,F AND H ARE STABILIZED. • Measure sediment accumulation levels in forebays and micropools. • EXISTING RIPRAP INLETS TO BE TAMPED AND COMPACTED TO FILL VOID SPACES. • Monitor the growth and survival of emergent wetlands and tree/shrub species. Record the • EXISTING SEDIMENT TRAPS TO BE FILLED WITH COMPACTED FILL, THEN TOPPED WITH TOPSOIL AND SEEDED. 12.1 .CS2 WILL REQUIRE MODIFICATIONS AS ATHLETIC FIELDS ARE CONSTRUCTED, SHIFTING TO THE EAST AND DECRASING IN species and approximate coverage, and note the presence of any invasive plant species. SIZE AND THE FOOTPRINT IS MINIMIZED DURING PLACEMENT FILL. • Inspect the condition of stormwater inlets to the wetland for material damage, erosion or 12.2.UPON REACHING STABILIZATION OF CONTRIBUTING WATERSHEDS, DIRECT FLOW FROM SBCS2 TO PREVIOULSY BLOCK I CONSTRUCTED FOREBAY OF WET POND 11. undercutting. 6.UPON STABILIZATION OF THE CONTRIBUTING WATERSHED TO BMP 11, STAGE 2 SEDIMENT BASINS SHALL BE REMOVED AND • Inspect upstream and downstream banks for evidence of sloughing, animal burrows, boggy CONSTRUCTION OF BMP 12 AND 13 SHALL COMMENCE. areas, woody growth or gully erosion that may undermine embankment integrity. - STAGE 2 SEDIMENT TRAP HS2a SHALL BE CONVERTED INTO LEVEL 2 BIORETENTION CELL H1.. • Inspect the wetland outfall channel for erosion, undercutting, rip -rap displacement, woody • STAGE 2 SEDIMENT BASINS SHALL BE DRAINED PRIOR TO START OF CONVERSION ACTIVITIES. RATE OF RELEASE SHALL BE . STAGE 2 SEDIMENT TRAP SHALL BE DRAINED PRIOR TO START OF CONVERSION ACTIVITIES. DRAINED FLUID/MATERIAL growth, ctc. CONTROLLED TO PREVENT FLOODING/EROSION OF DOWNSTREAM CHANNEL. DRAINED FLUID/MATERIAL SHALL BE FILTERED SHALL BE FILTERED AND CONTAINED IN A MANNER SUITABLE FOR PREVENTING DOWNSTREAM CONTAMINATION. • Inspect the condition of the principal spillway and riser for evidence of spalling, joint failure, AND CONTAINED IN A MANNER SUITABLE FOR PREVENTING DOWNSTREAM CONTAMINATION. . EXISTING RIPRAP INLETS TO BE TAMPED AND COMPACTED TO FILL VOID SPACES leakage, corrosion, etc. • EXISTING RISER AND BARREL STRUCTURE SHALL BE INSPECTED FOR DAMAGE OR CLOGGING AND REPAIRED OR CLEANED . EXISTING SEDIMENT TRAP TO BE FILLED WITH COMPACTED FILL TO ROUGH GRADE BOTTOM ELEVATION OF H1 . AS NECESSARY. KEY PLAN • EXISTING RIPRAP INLETS TO BE TAMPED AND COMPACTED TO FILL VOID SPACES. • A #57 GRAVEL LAYER OF 1 FOOT DEPTH SHALL BE INSTALLED ABOVE THE COMPACTED FILL. • EXISTING SEDIMENT BASINS/TRAPS THAT ARE NOT TO BE CONVERTED TO BIORETENTION FACILITIES TO BE FILLED WITH • A 6 INCH PERFORATED PVC UNDERDRAIN, ARRANGED IN A BRANCH PATTERN WITH 10 FOOT SPACING, SHALL BE INSTALLED • Inspect the condition of all trash racks, reverse -sloped pipes, and flashboard risers for COMPACTED FILL, TOPPED WITH 6 INCHES TOPSOIL AND SEEDED.. ABOVE THE GRAVEL LAYER THEN OVERLAIN WITH PEA GRAVEL AND COVERED WITH GEOTEXTILE. THE FINISHED evidence of clogging, leakage, debris accumulation, etc. • DEWATERING ORIFICES OF RISERS SHALL BE PATCHED OVER WITH GROUT. UNDERDRAIN SYSTEM SHALL HAVE A 1-2% SLOPE AND OUTFALL FROM THE DOWNSTREAM SIDE OF THE EXISTING RIPRAP • Inspect maintenance access to ensure it is free of woody vegetation, and check to see whether WEIR. valves, manholes and locks can be opened or operated. • A 61NCH ORIFICE SHALL BE CUT INTO THE RISERS FOR THE PROPOSED BIORETENTION CELL UNDERDRAINS. • RIPRAP OF EXISTING WEIR SHALL BE TAMPED AND COMPACTED TO FILL VOID SPACES, WHILE MAINTAINING THE EXISTING inspect internal and external side slopes of the wetland for evidence of sparse vegetative • A #57 GRAVEL LAYER OF 1 FOOT DEPTH SHALL BE INSTALLED ABOVE THE COMPACTED FILL. WEIR ELEVATION TO FINAL DESIGN GRADE AS DEPICTED ON DESIGN CROSS SECTIONS AND PROFILES HEREIN. cover, erosion, or slumping, and make needed repairs immediately. • A 6 INCH PERFORATED PVC UNDERDRAIN, ARRANGED IN A BRANCH PATTERN WITH 10 FOOT SPACING, SHALL BE INSTALLED • A MINIMUM 3 FOOT LAYER OF AMENDED SOIL SHALL BE INSTALLED TO FINISHED SURFACE ELEVATION. AMENDED SOIL ABOVE THE GRAVEL LAYER THEN OVERLAIN WITH PEA GRAVEL AND COVERED WITH GEOTEXTILE. THE FINISHED SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC MATTER; AND HAVE A PHOSPHORUS CONTENT OF • Cleanups should be scheduled at least once a year to remove trash, debris and floalables. UNDERDRAIN SYSTEM SHALL HAVE A 1-2% SLOPE TOWARDS THE RISER. 7 TO 21 mg/kg OR A P-INDEX OF 10 TO 30. • FOR 12/13, A MINIMUM 3 FOOT LAYER OF AMENDED SOIL SHALL BE INSTALLED TO THE FINISHED SURFACE ELEVATION. Based on inspection results, specific maintenance tasks will be triggered. Example maintenance AMENDED SOIL SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC MATTER; AND HAVE A 13. STAGE 2 SEDIMENT TRAPS IN BLOCK L WEST SHALL BE CONVERTED INTO LEVEL 2 BIORENTION FACILITIES. inspection checklists for Constructed Wetlands can be accessed in Appendix C of Chapter 9 of PHOSPHORUS CONTENT OF 7 TO 21 mg/kg OR A P-INDEX OF 10 TO 30 AS SPECIFIED IN VA. BMP STANDARDS AND the Virginia Stormwater Management Handbook (2010) or at the CWP website at: SPECIFICATIONS. • DUE TO PROPOSED FILL ACTIVITIES ASSOCIATED WITH PARK STREET, AND REQUIRED CONSTRUCTION OF RETAINING WALL, BIORETENTION FACILITIES WILL REQUIRE PHASED CONSTRUCTION, WITH THE SEDIMENT TRAPS BEING RAISED htto://www.cwp.orci/Resource Library/Controllina Runoff and Discharaes/sm.htm ISSUE 7. STAGE 2 DIVERSION CHANNELS SHALL BE FILLED, GRADED, AND STABILIZED WITH PERMANENT SEED. INCREMENTALLY PRIOR TO CONVERSION. (scroll to Too16: Plan Review, BMP Construction, and Maintenance Checklists) •• DO NOT BRING BIORETENTION FACILITY TO FINAL GRADE UNTIL UPSTREAM WATERSHED IS STABILIZED AND RETAINING 8. STAGE 2 SEDIMENT BASIN SBI1 SHALL BE CONVERTED INTO WET POND LEVEL 2 (BMP 11). WALLS ARE CONSTRUCTED. A more detailed maintenance inspection form is also available from Appendix B of CWP's • SEDIMENT BASIN SHALL BE DRAINED PRIOR TO START OF CONVERSION ACTIVITIES. DRAINED FLUID/MATERIAL SHALL BE • EXISTING WEIRS SHALL BE RAISED TO ADJUST TO SURROUNDING FILL GRADES AND MAINTAIN SEDIMENT CONTROL DURING Stormwater Pond and Wetland Maintenance Guidebook (2004). REV # DATE DESCRIPTION FILTERED AND CONTAINED IN A MANNER SUITABLE FOR PREVENTING DOWNSTREAM CONTAMINATION. PLACEMENT OF FILL. UPON REACHING FINAL ROUGH GRADE RIPRAP OF EXISTING WEIRS SHALL BE TAMPED AND • THE EXISTING STREAM CHANNEL SHALL BE DIVERTED AND/OR PUMPED AROUND THE PROPOSED FOOTPRINT OF COMPACTED TO FILL VOID SPACES, THEN ADDITIONAL RIP RAP PLACED TO ESTABLISH PROPOSED BMP WEIR ELEVATIONS. Managing vegetation is an important ongoing maintenance task at every constructed wetland and 1 03.02.2018 PER COUNTY COMMENTS. EXCAVATION (WITHIN APPROVED IMPACT AREAS ONLY). • INSTALL UNDER DRAINS AND RISER ASSOCIATED WITH EACH BMP PRIOR TO INSTALLATION OF BIORETENTION SOIL MEDIA. •• PLACE TEMPORARY CHECK DAM AT UPSTREAM END OF DIVERSION AND OUTFALL PROTECTION AT DOWNSTREAM SEE CONVERSION SEQUENCE DETAIL PROVIDED HEREIN. for each inundation zone. Following the design criteria above should result in a reduced need for TERMINUS OF DIVERSION. EXISTING SEDIMENT TRAPS TO BE FILLED WITH COMPACTED FILL THEN TOPPED WITH AN AMENDED SOIL LAYER OF 2-3 FOOT regular mowing of the embankment and access roads. Vegetation within the wetland, however, •• INSTALL INSTALL SUPER SILT FENCE DOWN SLOPE OF PROPOSED EXCAVATION. DEPTH TO FINISHED ELEVATIONS. AMENDED SOIL SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC will require some annual maintenance. • ROUGH GRADE SEDIMENT FOREBAYS (3) AT CONTRIBUTING CULVERT OUTFALLS AS DEPICTED ON DESIGN PLAN FOR BMP 11, MATTER; AND HAVE A PHOSPHORUS CONTENT OF 7 TO 21 mg/kg OR A P-INDEX OF 10 TO 30. SHEET XX. INSTALL RIP RAP FOREBAY MATERIALS UNDERLAIN WITH GEOTEXTILE FILTER FABRIC AS SHOWN IN DESIGN CROSS SECTIONS. • EXCAVATE PROPOSED WET POND AS SHOWN IN DESIGN PROFILE AND CROSS SECTIONS, REMOVING UNSUITABLE EXISTING EMBANKMENT MATERIALS FROM SITE AND/OR TO PREDEFINED/APPROVED SPOIL AREAS FOR DE -WATERING AND STABILIZATION. • INSTALL PRINCIPAL SPILLWAY AND EMERGENCY SPILLWAY AS DEFINED ON CROSS SECTIONS, DESIGN PROFILE AND DETAILS PROVIDED HEREIN. • STABILIZE ALL DISTURBED AREAS WITH STABILIZATION SEED MIX AND PLANT WET POND FRINGE AS DETAILED ON BMP 11 PLANTING PLAN, SHEET XX. SCLO D Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. STORMWATER CONSTRUCTION SEQUENCE FILEPATH:C:\UwmXHilaDmpboxtProjects=S RivannaNEMDesign and Analysis\CADW05_RivannaPH2_SWM_REV2.dvglHi11lApr 11, 2018 at 17:201Layout: 21 Storm Construction Sequence SWM 21 PLANTING NOTES: SHRUB AND TREE INSTALLATION: 1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 2. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS, AND FREE FROM DEFECTS, DECAY, DISEASES, INSECT PEST EGGS, AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH AND FREE FROM TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED. 3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF "THE AMERICAN STANDARD FOR NURSERY STOCK", PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250I STREET, N.W., SUITE 500, WASHINGTON, D.C. 20005. 4. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED. 5. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK. CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE BEEN GROWN. 6. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ONSITE SHALL BE STORED AND PROTECTED BY THE CONTRACTOR. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED FROM THE WIND AND SUN. PLANTS STORED ONSITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL. 7. NO SUBSTITUTIONS IN SIZE OR VARIETY OF PLANT MATERIAL SHALL OCCUR WITHOUT THE PRIOR APPROVAL OF THE ENGINEER OR LANDSCAPE ARCHITECT. 8. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE ENGINEER OF ANY VARIANCE FROM PLAN. 9. PLANTING OF WOODY PLANTS SHALL OCCUR WHEN VEGETATION IS NORMALLY DORMANT UNLESS OTHERWISE APPROVED BY THE ENGINEER OR LANDSCAPE ARCHITECT. 10. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. PLANTING SEQUENCING 1. CONTRACTOR IS RESPONSIBLE FOR THE LAYOUT OF ALL PLANT MATERIAL. 2. HOLES FOR INDIVIDUAL PLANTINGS SHALL BE EXCAVATED AS SHOWN IN THE DETAILS ON THIS SHEET. ALL PLANTING HOLES SHALL HAVE ROUGHED, SCARIFIED SIDES AND BOTTOMS. 3. CONTAINERIZED PLANTS SHALL BE SET IN THE PLANTING PIT AT THE PROPER DEPTH, ON TAMPED SOIL. SOIL REMOVED FROM THE PLANTING PIT AND SHALL THEN BE FILLED AROUND THE ROOTS AND TAMPED. 4. THE CONTRACTOR SHALL RESTORE DISTURBED AREAS TO INDICATED FINAL GRADES IF DISTURBED BY THE INSTALLATION OF SHRUBS AND TREES. 5. THE CONTRACTOR SHALL WATER EACH WOODY PLANT WITH THE FOLLOWING MINIMUM QUANTITIES OF WATER, UNLESS OTHERWISE DIRECTED BY THE ENGINEER: SP4-#2 CONTAINERS: 1 GALLON #3-#5 CONTAINERS: 2 GALLONS #7 CONTAINER OR LARGER: 3 GALLONS 6. CONTRACTOR SHALL APPLY 2-3 INCHES OF SHREDDED HARDWOOD MULCH IN AREAS WHERE HERBACEOUS AND WOODY CONTAINER PLANTS WILL BE INSTALLED. MULCH SHALL NOT BE APPLIED IN ANY SEEDED AREAS. PROJECT MAINTENANCE AND WARRANTY: 1. CONTRACTOR SHALL MAINTAIN INSTALLED PLANT MATERIAL WITHIN THE PROJECT LIMITS UNTIL FINAL ACCEPTANCE OF THE PROJECT BY THE ENGINEER. 2. CONTRACTOR SHALL BE RESPONSIBLE FOR HERBIVORY CONTROL MEASURES DEEMED NECESSARY TO PROTECT PLANTS DURING WARRANTY PERIOD. 3. FINAL PAYMENT TO THE CONTRACTOR WILL BE AUTHORIZED ONCE ALL SPECIFIED PLANT MATERIAL. IS DETERMINED TO BE HEALTHY AND INSTALLED AS PER SPECIFICATIONS. 4. CONTRACTOR SHALL PROVIDE A ONE-YEAR t00% REPLACEMENT WARRANTY ON ALL WOODY PLANT MATERIAL, AND 80% COVERAGE OF ALL AREAS SEEDED OR PLANTED WITH HERBACEOUS PLANT MATERIAL AFTER THE FIRST COMPLETE GROWING SEASON. REPLACEMENT RATES TO BE DETERMINED BY AVERAGING MORTALITY RATES FOUND IN RANDOM SAMPLE PLOTS. THE OWNER RESERVES THE RIGHT TO DETERMINE DIFFERENT MORTALITY RATES IN SPECIFIED AREAS WITHIN THE SITE. SEEDING NOTES: 1. ALL SEED MIXES ARE TO BE UNTREATED TESTED SEED OF GOOD QUALITY AND FREE OF NOXIOUS WEEDS. 2. ALL SEED SHALL BE DRY AND NOT MOLDY AND SHALL SHOW NO SIGN OF HAVING BEEN WET OR OTHERWISE DAMAGED. 3. EACH BAG OF SEED SHALL BE LABELED WITH THE NAME OF THE SEED MIX, PERCENTAGES OF EACH SPECIES IN THE MIX, AND THE SUPPLIER'S NAME, ADDRESS, AND PHONE NUMBER 4. THE CONTRACTOR SHALL USE THE SEED MIXES AND APPLICATION RATES AS SHOWN ON THE PLANT SCHEDULES. NO SUBSTITUTIONS SHALL BE ACCEPTED WITHOUT PRIOR PERMISSION FROM THE ENGINEER OR LANDSCAPE ARCHITECT. 5• CONTRACTOR SHALL PROTECT SEEDED AREAS PRIOR TO FINAL ACCEPTANCE. 6. SEEDED AREAS SHALL BE INSPECTED BY THE ENGINEER OR LANDSCAPE ARCHITECT AT THE COMPLETION OF THE SEEDING OPERATIONS AND ACCEPTED SUBJECT TO COMPLIANCE WITH SPECIFIED MATERIALS AND INSTALLATION REQUIREMENTS. 7. CONTRACTOR SHALL BE RESPONSIBLE FOR VERIFYING ACTUAL AMOUNT OF STABILIZATION SEED MIXES REQUIRED. BIORETENTION MAINTENANCE (1ST YEAR) 1. SEE MAINTENANCE AGREEMENTS PROVIDED UNDER SEPARATE COVER ALL MAINTENANCE SHALL BE CONDUCTED IN ACCORDANCE WITH VA. DEQ, STORMWATER DESIGN SPECIFICATION #9. • Initial inspections. For the first 6 months following construction, the site should be inspected at (cast twice after storm events that exceed I/2 inch of rainfall. • Spat Reseeding. Inspectors should look for hare or eroding areas in the contributing drainage area or around the bioretention area, and make sure they are immediately stabilized with grass cover. • Fertilization. Onotime, spot fertilization may be needed for initial plantings. • Watering. Watering is needed once a week during the first 2 months, and then as needed during first growing season (April-OctobcT), depending on rainfall. • Remove and replace dead plants. Since up to 100/. of the plant stock may dic off in the first year, construction contracts should include a Bare and replacement warranty to ensure that vegetation is properly established and survives during the first growing season following construction. The typical thresholds below which replacement is required are 85•/ survival of plant material and 1000%survival of trees. WET SWALE MAINTENANCE GUIDELINES 1. SEE MAINTENANCE AGREEMENTS PROVIDED UNDER SEPARATE COVER ALL MAINTENANCE SHALL BE CONDUCTED IN ACCORDANCE WITH VA. DEQ, STORMWATER DESIGN SPECIFICATIONS #3, 10 & 13. 2. DURING FIRST 6 MONTHS AFTER INSTALLATION, INSPECT AT LEAST TWICE AFTER RAINFALL EVENTS MORE THAN INCH. 3. LOOK FOR BARE AREAS AND RE -SEED, RE -PLANT IMMEDIATELY. REMOVE WOODY WETLAND VEGETATION IF CAUSING EROSION AND/OR SHORT CIRCUITING. REPEAT ANNUALLY. 4. INSPECT WET SWALE ANNUALLY FOR ACCUMULATION OF SEDIMENTS AT FOREBAY AND ALONG LOW FLOW AND HIGH FLOW CHANNELS. CAREFULLY REMOVE ACCUMULATED SEDIMENTS. 5• SEE ADDITIONAL SPECIFICATIONS PROVIDED ON SHEET SWM-XX NOTES: 1. PLANTING HOLE SHALL BE OF SUFFICIENT SIZE AS NOT TO CRAMP THE ROOTS. 2. PLANTING HOLE SHALL BE TAMPED WITH FOOT TO SECURE PLANT MATERIAL IN SOIL. 3"-4" SHREDDED HARDWOOD MULCH; PULL AWAY FROM BASE OF PLANT (WHERE REQUIRED) DETAIL: #7 CONTAINER INSTALLATION NOTES: 1. PLANTING HOLE SHALL BE OF SUFFICIENT SIZE AS NOT TO CRAMP THE ROOTS. 2. PLANTING HOLE SHALL BE TAMPED WITH FOOT TO SECURE CONTAINER PLANT MATERIAL IN SOIL. 2-3X'S BALL DIAMETER 2" X 2' HARDWOOD STAKE 'GALVANIZED WIRE GUY RUBBER HOSE REMOVE BURLAP FROM TOP 1 /3 OF BALL I►16� PLACE TOP OF ROOT BALL AT GRADE &-4" SHREDDED HARDWOOD MULCH; PULL AWAY FROM BASE OF PLANT (WHERE REQUIRED) LOOSEN ROOT BALL (BUTTERFLY) BEFORE PLANTING IN PLANTING PIT BACKFILL WITH MATERIAL REMOVED DURING PLANTING PIT EXCAVATION AND TAMP TO PREVENT SETTLEMENT SIDES AND BOTTOMS OF PLANTING PIT SHOULD BE ROUGHED AND SCARIFIED DETAIL: #SP4 AND #2 CONTAINER INSTALLATION NITS PLANTING MEDIA SPECIFICATIONS: SOIL SPECIFICATIONS: AMENDED SOIL SHALL CONSIST OF 85-88% SAND, 8-12% SOIL FINES, AND 3-5% ORGANIC MATTER; AND HAVE A PHOSPHORUS CONTENT OF 7 TO 21 mg/kg OR A P-INDEX OF to TO 30. (PER VIRGINIA DCR STORMWATER DESIGN SPECIFICATION NO. 9) WET SWALE AMENDED SOIL: SOIL SPECIFICATION: AMENDED SOIL SHALL CONSIST OF 50% COMPOST, BLENDED WITH EXISTING SITE SOILS. COMPOST SHALL BE DERIVED FROM PLANT MATERIAL. WELL COMPOSTED, FREE OF VIABLE WEEDS, STABLE WITH REGARD TO OXYGEN CONSUMPTION AND CARBON DIOXIDE GENERATION, AND SHALL MEET U.S. COMPOSTING COUNCIL, STA COMPOST TECHNICAL DATA SHEET STANDARDS, (PER VIRGINIA DCR STORMWATER DESIGN SPECIFICATION NO. 4) DRY SWALE: SOIL SPECIFICATION: AMENDED SOIL SHALL CONSIST OF 85-88% SAND FINES, AND 3-5% ORGANIC MATTER, AND HAVE A PHOSPHORUS CONTENT OF 7 TO 21 mg/kg OR A P-INDEX OF 10 TO 30. (PER VIRGINIA DCR STORMWATER DESIGN SPECIFICATION NO. 9) BIORETENTION MAINTENANCE (SCHEDULE) 1. SEE MAINTENANCE AGREEMENTS PROVIDED UNDER SEPARATE COVER. ALL MAINTENANCE SHALL BE CONDUCTED IN ACCORDANCE WITH VA. DEQ, STORMWATER DESIGN SPECIFICATION #9. Maintenance Tasks Frequency • Mowing of grass filler strips and bioretention turf cover At least 4 times a year • Spot weeding, erosion repair, trash removal and mulch raking Tvnce during rowin season • Add reinforcement planting to maintain desired the vegetation density As needed • Remove invasive plants using recommended control methods • Stabilize the contributing drainage area to prevent erosion • Spring inspection and cleanup • Supplement mulch to maintain a 3 inch layer Annually • Prune trees and shrubs Remove sediment in re -treatment cells and inflow points Once every 2 to 3 ears • Replace the mulch layer Every 3 years GRASS SWALE MAINTENANCE GUIDELINES 1. SEE MAINTENANCE AGREEMENTS PROVIDED UNDER SEPARATE COVER. ALL MAINTENANCE SHALL BE CONDUCTED IN ACCORDANCE WITH VA. DEQ, STORMWATER DESIGN SPECIFICATION #3. 2. GRASS CHANNEL INSPECTIONS SHALL OCCUR ANNUALLY EACH SPRING. ADD REINFORCMENT PLANTING AND RE -SEED TO MAINTAIN go% TURF COVER MAINTAIN HYDRAULIC FLOW AREA. 3. REMOVE ANY ACCUMULATED SAND OR SEDIMENT DEPOSITS BEHIND CHECK DAMS (IF ANY). 4. EXAMINE CHANNEL BOTTOM FOR EVIDENCE OF EROSION, BRAIDING, EXCESSIVE PONDING OR DEAD GRASS. CHECK INFLOW POINTS FOR CLOGGING AND REMOVE ANY SEDIMENT. 5. INSPECT SIDE SLOPES FOR EVIDENCE OF EROSION AND REPAIR WITH MATTING & RESEED. BIORETENTION SOIL SPECIFICATIONS: Mafxrial Specification Notes Filter Media to contain: Filter Media • 85%-88% sand The volume of filter media based on 110% Composition + 8%-12% soil fines of the plan volume, to account for settling • 3%-5% organic matter in the form or compaction_ of leaf compost P-Index range= 10-30, OR Filter Media Between 7 and 21 mglkg of P in the The media must be procured from Testing soil media. approved filter media vendors. CECs greater than 10 Mulch Layer Use aged, shredded hardwood bark Lay a 2 to 3 inch layer on the surface of the mulch filter bed. Alternative Use river stone or pea gravel, coir and Lay a 2 to 3 inch layer of to suppress weed Surface Cover jute matting, or turf cover. growth. Loamy sand or sandy loam texture, Top Soil with less than 5% clay content, pH 3 inch surface depth. For Turf Cover corrected to between 6 and 7, and an orcianic matter content of at least 2%. Use a non -woven gectextile fabric with Apply only to the sides and above the Geotextile/Liner a flow rate of ? 110 gal.fmin.fsq, ft. underdrain. For hotspots and certain karst (e.g., Geotex 351 or equivalent) sites only, use an appropriate liner on bottom. Choking Layer Lay a 2 to 4 inch layer of sand over a 2 inch layer of choker stone (typically #8 or ft89 washed ravel which is laid over the underdrain stone. Stone Jacket far 1 inch stone should be double -washed 12 inches for the underdrain; Ua and clean and free of all fines (e.g.. 12 to 18 inches for the stone storage layer, and/or Storage VDOT #57 stone)_ if needed Layer L Use 6 inch rigid schedule 40 PVC pipe Lay the perforated pipe under the length of Underdrains, (or equivalent corrugated HDPE for the bioretention cell, and install non- micro-bioretention), with 318-inch perforated pipe as needed to connect with Observation Perforations at 6 inches on center; the storm drain system. Install T's and Y's Wells Position each underdrain on a 1% or as needed, depending on the underdrain 2% slope located nor more than 20 configuration. Extend cleanout pipes to the feet from the next pipe. surface with vented caps at the Ts and Ys. Establish plant materials as specified in the Plant one tree per 250 square feet (15 landscaping plan and the recommended feet on -center, minimum 1 inch plant list. caliper). In general, plant spacing must be sufficient Shrubs a minimum of 30 inches high to ensure the plant material achieves 80% planted a minimum of 10 feet on- cover in the proposed planting areas within Plant Materials center. a 3-year period. Plant ground cover plugs at 12 to 18 If seed mixes are used, they should be inches on -center; Plant container- from a qualified supplier, should be grown plants at 18 to 24 inches an- appropriate for stormwater basin center, depending on the initial plant applications, and should consist of native size and how large it will grow. species (unless the seeding is to establish maintained turf). SOURCE: VA DCR STORMWATER DESIGN SPECIFICATION NO. 9, MARCH 2011. SOIL AMENDMENTS SPECIFICATION: FILTER MEDIA TO CONTAIN: 85%-88% SAND 8%-12% SOIL FINES 3%-5% ORGANIC MATTER IN THE FORM OF LEAF COMPOST MULCH LAYER USE AGED, SHREDDED HARDWOOD BARK MULCH SOURCE: VA DCR STORMWATER DESIGN SPECIFICATION NO. 9, MARCH 2O11 u F Soil Amendments - Overall Recommendation TSP 181 Ibs/ac 0-50-0 Muriate of potash 149 Ibs/ac 0-0-60 Calcitic limestone 1 tons/ac Fertilizer (29-3-7) 150 Ibs/ac TREE PLANTINGS (SEE IANDSCAPE PLAN FOR DETAILED SPECIES SPECIFICATIONS) AMENDED SOIL COMPOST AMENDED SOIL SPECIFICATIONS: 1. COMPOST SHALL BE DERIVED FROM PLANT MATERIAL AND PROVIDED BY A MEMBER OF THE U.S. COMPOSTING SEAL OF TESTING ASSURANCE (STA) PROGRAM. SEE W W W.COMPOSTINGCOUNCIL.ORG FOR A LIST OF LOCAL PROVIDERS. 2. THE COMPOST SHALL BE THE RESULT OF THE BIOLOGICAL DEGRADATION AND TRANSFORMATION OF PLANT -DERIVED MATERIALS UNDER CONDITIONS THAT PROMOTE ANAEROBIC DECOMPOSITION. THE MATERIAL SHALL BE WELL COMPOSTED, FREE OF VIABLE WEED SEEDS, AND STABLE WITH REGARD TO OXYGEN CONSUMPTION AND CARBON DIOXIDE GENERATION. THE COMPOST SHALL HAVE A MOISTURE CONTENT THAT HAS NO VISIBLE FREE WATER OR DUST PRODUCED WHEN HANDLING THE MATERIAL.. IT SHALL MEET THE FOLLOWING CRITERIA, AS REPORTED BY THE U.S. COMPOSTING COUNCIL STA COMPOST TECHNICAL DATA SHEET PROVIDED BY THE VENDOR.. COMPOST SOIL AMENDMENTS MAINTENANCE (1ST YEAR) (TAKEN FROM THE VIRGINIA DEQ STORMWATER DESIGN SPECIFICATION NO.4 FOR SOIL COMPOST AMENDMENTS, VERSION 1.9) 1. INITIAL INSPECTIONS. FOR THE FIRST SIX MONTHS FOLLOWING THE INCORPORATION OF SOIL AMENDMENTS, THE SITE SHOULD BE INSPECTED AT LEAST ONCE AFTER EACH STORM EVENT THAT EXCEEDS. -INCH OF RAINFALL. 2. SPOT RESEEDING. INSPECTORS SHOULD LOOK FOR BARE OR ERODING AREAS IN THE CONTRIBUTING DRAINAGE AREA OR AROUND THE SOIL RESTORATION AREA AND MAKE SURE THEY ARE IMMEDIATELY STABILIZED WITH GRASS COVER. 3. FERTILIZATION. DEPENDING ON THE AMENDED SOILS TEST, A ONE-TIME, SPOT FERTILIZATION MAY BE NEEDED IN THE FALL AFTER THE FIRST GROWING SEASON TO INCREASE PLANT VIGOR 4. WATERING. WATER ONCE EVERY THREE DAYS FOR THE FIRST MONTH, AND THEN WEEKLY DURING THE FIRST YEAR (APRIL-OCTOBER), DEPENDING ON RAINFALL. 5• ONGOING - THE OWNER MAY WANT TO DE -THATCH THE TURF EVERY FEW YEARS TO INCREASE PERMEABILITY. FOREST/OPEN SPACE MAINTENANCE SPECIFICATIONS (TAKEN FROM THE VIRGINIA DEQ STORMWATER DEFINITION OF FOREST/OPEN SPACE AS PROVIDED IN THE CURRENT STORMWATER REGULATIONS AT THE TIME OF PLAN PREPARATION): 1. FOREST OPEN SPACE AREAS ARE DEPICTED ON SHEET SWM-25 OF THE STORMWATER MANAGEMENT PLANS. FOREST /OPEN SPACE AREAS THAT ARE CREDITED IN THE ASSOCIATED VRRM CALCULATIONS ARE EITHER PRESERVED AND PROTECTED FROM DISTURBANCE OR RESTORED USING COMPOST AMENDED SOILS PER SPECIFICATION #4 OF THE BMP CLEARINGHOUSE STANDARDS AND SPECIFICATIONS (INCORPORATED BY REFERENCE HEREIN). 2. FOREST/OPEN SPACE AREAS DEPICTED ON SHEET SWM-25 AND PROTECTED BY DEED OF RESTRICTION SHALL BE MAINTAINED IN HYDROLOGICALLY FUNCTIONAL STATE IN PERPETUITY. 3. FOREST/OPEN SPACE AREAS SHALL NOT BE MOWED ROUTINELY AND SHALL BE BUSH -HOGGED NO MORE THAN FOUR (4) TIMES A YEAR. WATERING. WATER ONCE EVERY THREE DAYS FOR THE FIRST MONTH, AND THEN WEEKLY DURING THE FIRST YEAR (APRIL-OCTOBER), DEPENDING ON RAINFALL. 4. FOREST/OPEN SPACE AREAS AS SHOWN ON SHEET SWM-25 MUST REMAIN INA NATURAL VEGETATED STATE AND SHALL BE MAINTAINED AS SUCH. 5. FOREST/OPEN SPACE AREAS SHALL NOT BE CONVERTED TO IMPERVIOUS OR TURF UNLESS ACCOMPANIED BY A REVISION TO THE STORMWATER MANAGEMENT CALCULATIONS, DEED OF RESTRICTIONS AND MAINTENENACE AGREEMENTS. 6. TO MAINTAIN FOREST/OPEN AREAS, DEAD, DYING AND DISEASED VEGETATION MAYBE REMOVED PERIODICALLY. 7. TO MAINTAIN FOREST OPEN/SPACE AREAS, INVASIVE SPECIES MAY BE TREATED AND REMOVED PERIODICALLY. ALL ENGINEERED SOIL MEDIA MUST MEET THE REQUIREMENTS AS SPECIFIED IN THE SOURCE: VA DCR STORMWATER DESIGN SPECIFICATION NO. 9, MARCH 2O11. CONTRACTOR TO PROVIDE TEST RESULTS INDICATING COMPLIANCE PRIOR TO PLACMENT BIODEGRADABLE EROSION CONTROL MATTING (EC-2) (SEE SPECIFICATION: FOR ADDITIONAL MATTING DETAIL) TOPSOIL TO BE TOPDRESSED WITH 2" OF COMPOST THEN DEEP TILLED INTO UNDERLYING SOIL MEDIA. RIPPED EXISTING SOIL (TOPSOIL OPTIONAL) \\ EXISTING SUBSOIL X� 1.1. 1o0% OF THE MATERIAL MUST PASS THROUGH A HALF INCH SCREEN. 1.2. THE PH OF THE MATERIAL. SHALL BE BETWEEN 6 AND 8. 1.3. MANUFACTURED INERT MATERIAL (PLASTIC, CONCRETE, CERAMICS, METAL, ETC.) SHALL BE LESS THAN 1.0% BY WEIGHT. 1.4. THE ORGANIC MATTER CONTENT SHALL BE BETWEEN 35% AND 65%. 1.5• SOLUBLE SALT CONTENT SHALL BE LESS THAN 6.0 MMHOS/COM. 1.6. MATURITY SHOULD BE GREATER THAN 8o%. 1.7. STABILITY SHALL BE 7 OR LESS. 1.8. CARBON/NITROGEN RATIO SHALL BE LESS THAN 25:1. 1.9. TRACE METAL TEST RESULT = "PASS". 1.10. THE COMPOST MUST HAVE A DRY BULK DENSITY RANGING FROM 4o TO 50 LBS. CF. DETAIL: ROOFTOP DISCONNECTION WITH VEGETATED FILTER STRIP (NATURAL DISPERSION). (VA. BMP SPECIFICATION *1). NTS RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA BCE Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p:757-870-4825 13�7,I_1� ISSUE IREV # DATE DESCRIPTION 1 03.02.2018 1 PER COUNTY COMMENTS. PLT H OF Dr�� v SCOTT C. BLOSSOM y Lac. No. 40287 0 INNAL 'i Job No: 1005 Drawn By: BCE Date: 12.04.2017 Checked By: Scott C. Blossom, P.E. PLANTING NOTES AND DETAILS SWM - 22 LEGEND t EXISTING CONTOURS OEXISTING STRUCTURES EXISTING TREELINE ♦♦ PROJECT LIMITS ♦♦ STUDY LIMITS NODE1 DRAINAGE NODE on i SUBWATERSHED LABELS a.z nc SUBWAT RSHED BOUNDAEYLIMI ' BOUNDARY LIMITS STUDY STUDYOUTFALL LOCATION EXISTING PARCELS RESOURCE PROTECTION AREA yyy yy APPROXIMATE �y yy y"y WETLAND LIMITS 4 Jr Jr EXISTING CHANNELS (PER HENRICO COUNTY GIS) APPROXIMATESTREAM CHANNEL LIMITS ODIRECTION OF FLOW OAPPROXIMATE SOIL DuB2� BOUNDARIES TC FLOW PATH i OENERGY BALANCE NODE (POND OUTFACE = NODE A) OEXISTING FOREST/OPEN SPACE AREA OEXISTING MANAGED TURF AREA OEXISTING IMPERVIOUS AREA \ DA 4AA n 46B C) •• � '°ao � I � �_� A _ � ♦ � i 1 i DA 3B � � I Yoo � 3yo � •'-_ / -_ � 954 AC moo i / . • 1 S I 3B0 A g0 / \ \/ 0 1-6 � I � ■ DA3A NODE 3B r \ DE 1 zas7Ac �� 51C (C/D)��� I, �, ( 51B (C 76 ■ J4110 I� NODE 4A ` �. �•. i 'III ■ �. ■�''� / �� � p o ♦♦� �° DA ♦ , / ♦ / `V �a-a ♦ 1' �� z7.o5 AC �3s0 J`'�5 ♦ ♦ \ 370 1 �a� - • ,r I • �a. i as b DA B 380 9.ioAC `_"__ „I � ��J A ♦ 3q.o6 AC ��� 62B (C) - �_- _ ��� //1 B (B) i � aaz �� 4 ■ 30 ■ • ,--,,/� vn %� NODE 51C (C/D) V�� • .� _ i � I � NODE 3A ��/ �� �1 B (C/D) ( �(� �� � 1\ /�� � � � � ♦♦ � � �♦♦ ass BB �� �\�� � � 51B (C/D) DAA41) .. i �v ♦+� r � NODE 5 -♦♦ ♦ \ - - T r 51 B (C/D) mo • t +o , A .. / NODE A � Art ass � Rg411C 1 N• i IsoI IsoI Itu NODE 6 i � / NODE 1 I� a•r•`•r•��� \ • - aa�� i � 360 / � �aa aaaaraaa��V \ ♦ � /� � 4 ,�� �/ I W � 1 NODE 7 ♦ 4 / DA1 51C (C/D) ,\'law )ON, 380 D s�o (C) SCALE: 1 INCH = 20o FEET EXISTING WATERSHED MAP N E I _')�& SCALE: 1 INCH = 2oo FEET 0100' 200 400' 7p!c EXISTING CONDITIONS HYDROLOGY SUMMARY NOAA ATLAS 14 RAINFALL DATA FOR PROJECT SITE STORM EVENT (YR) RAINFALL (IN) 1 2.90 2 3.51 10 5.31 25 6.53 100 8.73 BENTLEY SYSTEMS'PONDPACK DRAINAGE AREA INPUT SUMMARY DRAINAGE AREA AREA (AC) CN Tc (HR) DA 1 19.28 72.1 0.233 DA 2 34.04 74.4 0.199 DA 3A 28.87 72.5 0.208 DA 3B 9.55 75.4 0.221 DA 4A 31.06 76.7 0.202 DA 4B 9.10 71.4 0.281 DA 5 27.05 74.6 0.378 DA 6 7.43 72.2 0.193 DA 7 8.94 71.2 0.289 DA-A 2.55 75.2 0.294 TOTAL 177.37 TR-55 DRAINAGE AREA PEAK DISCHARGE SUMMARY DRAINAGE AREA Q1 (CFS) Q2 (CFS) Q10 (CFS) Q25 (CFS) Q100 (CFS) DA 1 18.26 28.26 61.72 86.29 132.37 DA 2 39.97 59.79 124.61 170.86 256.52 DA 3A 29.37 44.97 97.29 135.67 207.50 DA 3B 11.50 16.93 34.82 47.58 71.18 DA 4A 41.56 60.34 121.18 164.16 243.18 DA 4B 7.44 11.76 26.39 37.13 57.35 DA 5 23.87 35.84 75.76 104.58 158.24 DA 6 7.57 11.66 25.38 35.33 54.03 DA 7 7.12 11.20 25.39 35.82 55.48 DA A 2.68 3.99 8.28 11.34 17.01 TR-55 NODE PEAK DISCHARGE SUMMARY NODE Q1 (CFS) Q2 (CFS) LIST Q25 (CFS) Q100 (CFS) NODE 1 18.26 28.26 61.72 36.29 132.37 NODE 2 39.97 59.79 124.61 170.86 256.52 NODE 3A 40.83 61.89 132.10 182.96 278.21 NODE 3B 11.50 16.93 34.82 47.58 71.18 NODE 4A 41.56 60.34 121.18 164.16 243.18 NODE 4B 48.63 71.40 145.88 198.95 297.39 NODE 5 23.87 35.84 75.76 104.58 158.24 NODE 6 7.57 11.66 25.38 35.33 54.03 NODE A 92.01 137.11 285.77 392.66 591.54 OUTFALL 184.48 278.21 586.81 809.37 1225.14 SOILS SUMMARY TABLES WATER TABLE MAP HYDROLOGIC SURFACE KSAT UNIT SOIL NAME SLOPE SOIL GROUP RUNOFF UPPER LOWER (IN/HR) LIMIT LIMIT ABELL SILT 0.57 - 16 LOAM 2 - 7 % B MEDIUM 2.0-3.5 >6.0 1.98 46B LIGNUM 2 - 7 % C HIGH 1 1 0.00 - SILT LOAM .0-2.5 .8-3.0 0.06 MANTEO 1 98 51 B CHANNERY 2-7 % C/D LOW - - 5.95 SILT LOAM MANTEO 1 98 51 C CHANNERY 7 - 15 % C/D LOW - - 5.95 SILT LOAM 62B NASON 2 - 7 % C MEDIUM - - 0.57 - SILT LOAM 1.98 W WATER - - - - - - SOIL SURVEY GEOGRAPHIC (SSURGO) DATABASE FOR ALBEMARLE COUNTY, VA SOURCE: U.S. DEPARTMENT OF AGRICULTURE, NATURAL RESOURCE CONSERVATION SERVICE RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA IBCE CIVIL ENGINEER Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p: 757-8704825 KEY PLAN ISSUE REV # I DATE I DESCRIPTION 1 1 1 03.02.2018 1 PER COUNTY COMMENTS. I r� j,TH OF' Dr�f 0o SCOTT C. Lic. No. BLOSSOM m 40287 ,off o �'5s10NAL'e �c�, I Job No: 1005 1 Drawn By: BCE I I Date: 12.04.2017 1 Checked By: Soon C. Blossom, P.E. I I PRE -DEVELOPMENT HYDROLOGY I SWM-23 LEGEND tEXISTING �17�- CONTOURS OEXISTING STRUCTURES EXISTING TREELINE ♦♦ PROJECT LIMITS ♦♦ STUDY LIMITS NODE1 DRAINAGE NODE on, SUBWATERSHED LABELS a.z nc SUBWAT RSHED BOUNDAEYLIMI ' BOUNDARY LIMITS STUDY STUDYOUTFALL LOCATION EXISTING PARCELS RESOURCE PROTECTION AREA yyy yy APPROXIMATE �y yy yy WETLAND LIMITS 4 Jr Jr EXISTING CHANNELS (PER HENRICO COUNTY GIS) APPROXIMATESTREAM CHANNEL LIMITS DIRECTION OF FLOW O OAPPROXIMATE SOIL DuB2� BOUNDARIES TC FLOW PATH i OENERGY BALANCE NODE (POND OUTFACE = NODE A) OFOREST/OPEN SPACE AREA 0 FOREST/OPEN SPACE CONSERVATION EASEMENT AREA OMANAGED TURF AREA OIMPERVIOUS AREA • OPEN WATER 10 too / / DA [A31-29 AC 6�\.\� / \ -�% DAgB 46B C) _ 9.54AC a, ♦• / , / "a. .� , I , 411 ■ ' �♦, NODE 3B , ON ' A 51C (C/D) ,♦� �51 °i 62B (C) DA3A ♦ NODE 4A ����Q/ , 1111 1 , z5.59 AC \�` �.. t ♦ rev M 51B (C/D) jl I( / 36o RASA �\ ' " r�' ♦ ( Eu • .. ,� � � A. ♦ ♦ / � i 5.45 AC I ♦ ` � � DA 4B o� 01100 00 34.43 A: \ o - ♦`\ •� �_1• /• / ' \°"° ^ ✓ '� ` 62B (C) I �: i/ ` ) ,,o !`` _ _♦` 1B (B) -. S /// /// DAgB, �\ �- ` / _. 7•2onc \h " \ ■ .,e�j / _ '��' ` NODE 4B 51 C-(�C/D ) / NODE3A • - 51B (C/D)� �r i / • ♦ ♦� �� 51C (C/D) `� 36g36B ■ ' `\� �_�� 1. ° t is is my UM 1 • ` F70 _ Zzz a � ®\NODE 5 l/ �■�\�`� ♦♦ jj 7 0 a _ ���� ♦� Ar 6B (�) � y ss ♦� NODE 2L ♦ DA7�� `r MAN �� II� ` • ', r � i ` 1 3sz ♦ 8.44 AC \`\ ' / NODE 6� - -_" - • I1\/ �� \' ' �� i/ -'sso NODE 1� ' • 4 0'�'1 ,rv' ' NODE 7 / DA1 51C (C 19.32 AC 4 j i.\ ou L. \ / �0\ _ 51B (C/D',� � \ \ 51C (C/D) \ �v so v� v ��v /D)/ \\ 46B (C) SCALE: 1 INCH = 20o FEET PROPOSED WATERSHED MAP N SCALE: 1 INCH = 2oo FEET o' 100' 200' 400' PROPOSED (UNROUTED) CONDITIONS HYDROLOGY SUMMARY NOAA ATLAS 14 RAINFALL DATA FOR PROJECT SITE STORM EVENT (YR) RAINFALL (IN) 1 3.00 2 3.63 10 5.48 25 6.72 100 8.96 BENTLEY SYSTEMS' PON DPACK DRAINAGE AREA INPUT SUMMARY DRAINAGE AREA AREA (AC) POST CN 1YR CN-LID 2YR CN-LID 10YR CN-LID Tc(HR) DA 1 19.33 74.7 73.4 73.6 74.0 0.233 DA 2 32.71 80.0 75.7 76.4 77.3 0.199 DA 3A 25.74 82.5 79.5 79.9 80.5 0.208 DA 3B 9.54 75.5 75.5 75.5 75.5 0.221 DA 4A 31.16 75.2 75.2 75.2 75.2 0.202 DA 4B 10.22 78.9 74.6 75.3 76.3 0.281 DA 5 21.07 83.1 83.1 83.1 83.1 0.405 DA 5A 4.98 78.2 78.2 78.2 78.2 0.145 DA 5B 7.67 80.0 74.2 75.2 76.5 0.266 DA 6 7.44 76.6 76.6 76.6 76.6 0.193 EDA 7 76.1 76.1 76.1 76.1 0.289 E1743 TR-55 DRAINAGE AREA PEAK DISCHARGE SUMMARY DRAINAGE AREA Q1 (CFS) Q2 (CFS) Q10 (CFS) Q25 (CFS) Q100 (CFS) DA 1 21.82 32.49 67.54 92.73 139.58 DA 2 53.35 74.64 141.02 186.81 270.76 DA 3A 46.74 64.01 117.01 153.16 213.46 DA 3B 11.58 17.02 34.92 47.69 71.27 DA 4A 38.27 56.41 116.25 158.95 237.91 DA 4B 13.71 19.49 37.83 50.60 73.92 DA 5 29.15 39.77 72.37 94.88 135.61 DA 5A 7.90 11.26 22.01 29.51 43.24 DA 5B 11.25 15.78 29.93 39.70 57.52 DA 6 10.08 14.64 29.27 39.62 58.72 DA 7 9.54 14.08 28.80 39.24 58.52 TR-55 NODE PEAK DISCHARGE SUMMARY NODE Q1 (CFS) Q2 (CFS) Q10 (CFS) Q25 (CFS) Q100 (CFS) NODE 1 21.82 32.49 67.54 92.73 139.58 NODE 2 53.35 74.64 141.02 186.81 270.76 NODE 3A 58.26 30.85 151.56 200.43 239.27 NODE 3B 11.58 16.90 34.92 47.69 71.27 NODE 4A 38.27 56.41 116.25 158.95 237.91 NODE 4B 51.62 75.39 152.46 207.36 308.60 NODE 5 26.15 26.15 50.16 66.80 97.12 NODE 6 10.08 14.64 29.27 39.62 58.72 NODE A 135.02 190.86 366.76 489.66 714.31 OUTFALL 246.96 350.57 680.55 911.95 1335.46 TR-55 NODE PEAK DISCHARGE SUMMARY (ROUTED THROUGH BMP 11 AND CN-LID ADJUSTMENTS APPLIED WHERE APPLICABLE) NODE Q1 (CFS) Q2 (CFS) Q10 (CFS) Q25 (CFS) Q100 (CFS) NODE 1 20.04 30.71 66.03 92.73 139.58 NODE 2 41.64 63.37 130.74 186.81 270.76 NODE 3A 51.61 74.35 145.64 200.43 289.27 NODE 3B 11.57 16.90 34.90 47.69 71.27 NODE 4A 38.23 56.35 110.11 158.95 237.91 NODE 4B 48.37 72.20 149.52 207.36 308.60 NODE 5 15.14 22.87 47.15 66.80 97.12 NODE 6 10.08 14.64 29.27 39.62 58.72 NODE A 34.17 84.1 .7 271.08 489.66 714.31 OUTFALL 102.71 171.92 526.30 911.95 1335.46 SOILS SUMMARY TABLES WATER TABLE MAP HYDROLOGIC SURFACE KSAT UNIT SOIL NAME SLOPE SOIL GROUP RUNOFF UPPER LOWER (IN/HR) LIMIT LIMIT ABELL SILT 0.57 - 16 LOAM 2 - 7 % B MEDIUM 2.0-3.5 >6.0 1.98 460 SILT LOAM .0-2.5 1 .8-3.0 0.06 MANTEO 51 B CHANNERY 2-7 % C/D LOW - - 1 96 5.95 SILT LOAM MANTEO 51 C CHANNERY 7 - 15 % C/D LOW 1 98 5.95 SILT LOAM 62B NASON ° 2-7 /o C MEDIUM - - 0.57 - SILT LOAM 1.98 W WATER - - - SOIL SURVEY GEOGRAPHIC (SSURGO) DATABASE FOR ALBEMARLE COUNTY, VA SOURCE: U.S. DEPARTMENT OF AGRICULTURE, NATURAL RESOURCE CONSERVATION SERVICE RIVANNA VILLAGE: STORMWATER PLAN AMENDMENT 1 AND PHASE II ALBEMARLE COUNTY, VIRGINIA IBCE CIVIL ENGINEER Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 p: 757-8704825 KEY PLAN ISSUE REV # I DATE I DESCRIPTION 1 1 1 03.02.2018 1 PER COUNTY COMMENTS. I rT � j,H OF' Dr�f 0o f z SCOTT C. Lic. No. BLOSSOM m 40287 ��ssIONAL ��� I Job No: 1005 1 Drawn By: BCE I I Date: 12.04.2017 1 Checked By: Soon C. Blossom, P.E. I I POST -DEVELOPMENT HYDROLOGY I SWM-24 LEGEND RIVANNA VILLAGE: PHASE i PROJECT LIMITS (APPROY-) STORMWATER PLAN �j PHASE 2 PROJECT LIMITS Ir j`rr �"err �o a AMENDMENT 1 AND PHASE II i ALBEMARLE COUNTY, VIRGINIA mym°m ��mymy SURVEYED WETLAND LIMITS aoc 4 6 J � R � \ SURVEYED STREAM,♦♦♦♦ CHANNEL LIMITS S 420 ♦ �� 0� �O� A........ �`go O PROPOSED IMPERVIOUS AREA (PER VRRM) 430 � a % POW vv � ♦�♦♦ v o0 ^� \\ o I /� \ ♦,i♦, 3g� \ �o _ a� - �,\\ \�\\� ♦♦� \'.: \\ 3so ♦ PROPOSED FOREST/OPEN SPACE CONSERVATION EASEMENT CREDITED IN VRRM (22.34 ACRES AS SHOWN) PROPOSED FOREST OPEN SPACE o o v �ti° 1 ��\� 11111 �_ ,♦♦� I I ^ �_ I I I ♦♦, AREAS INCLUDED IN FOREST/OPEN I I I i V ♦♦ SPACE EASEMENT AREA TO BE PROPOSED GRADING IN STEEP FOREST/OPEN RECORDED AND PROTECTED BY SPACE AREAS (PORTIONS >10%SLOPES) ARE I / I I I I I I 1 ♦ ♦♦, DEED RESTRICTIONS, BUT ARE NOT INCLUDED IN THE AREA TO BE PROTECTED BY ♦♦, i INCLUDED IN THE VRRM DEED RESTRICTIONS AND RECORDED IN A " ♦♦ CALCULATIONS FOR STORMWATER FOREST/OPEN SPACE EASEMENT BUT IS NOT \ IBCE ` ,♦ CREDIT CREDITED IN THE VRRM CALCULATIONS. ♦ MEN CONSERVATION EASEMENT NOT CREDITED IN VRRM (6.03 ACRES AS SHOWN) AREAS WERE PREVIOUSLY SHOWN/CREDITED AS FOREST/OPEN -\ I I I I i \ J /) / ` .ate —� _ _ �'!♦♦/'� m ���CIVIL , ♦ c `♦♦ ♦" I ♦ oA `°"e, J I r o \` _ I ' `♦♦, ♦♦, M � �, �j n��ej�e„` ENGINEER Blossom Consulting and Engineering Inc. 1101 Professional Drive, Suite G Williamsburg, VA 23185 \ PROPOSED STORMWATER BMP SPACE IN PHASE 1 PLAN APPROVALS. THESE AREAS WILL BE PROTECTED BY DEED RESTRICTIONS AND SHOWN ON THE / - -���=' MR° I J w 1 ,+ 1 \ j T L � - �l' � I. 13. r / ' \� r j ♦I, I♦ \ T� I ♦♦ > ,♦♦ A�♦♦♦♦ �� p: 757-870-4825 PROPOSED PHII BMP MAINTENANCE EASEMENT OBE RECORDED PRIOR TO PLAN APPROVAL) FOREST/OPEN SPACE EASEMENT PLAT, BUT ARE NOT INCLUDED IN THE VRRM CALCULATIONS. `` __� \ : ( �' `� u - ) \ / r ! `1 /\ �•�• \ a,♦♦,♦ 4 -"'\ \ \ \\ / ' ,• ♦'. �, ROW \\ \\ , \\ STORM DRAINAGE \\PROPOSED EASEMENT (SEE SITE PLANS PROVIDED BY ALAN FRANKLIN P.E.) ,'�� Yi- \ \ / ' , ' �� \ \J :\ �i♦ \ •• \ �' _� `a \ \ , 1°^a. PROPOSED RIGHT-OF-WAY LIMITS / ♦ s� w"� °' ♦� \ \ \\\, \`` ��\� \ �� �\ \ \\ x m I \ �t\� \�`�. (SEE SITE PLANS PROVIDED BY ALAN FRANKLIN P.E.) l l `t♦ r \ `v �� ��w Pv ��-C�� �� �A\ �\ I i �� �� /\ a\\ ti •°� I \ \ PROPOSED SANITARY SEWER EASEMENT (SEE SITE PLANS BY ALAN FRANRLIN P.E. PROPOSED TRAIL / o A /� �4 oA� \ w ♦ \ � / oW\vv� A vv / 1 V� - \ \ .J _ ( .. �) �\� A v ` \� A - I I 1 � `% \�1,,,�,' �� \`" '/ A/(�. �\ A (NOT INCLUDED IN VRRM AS FOREST/OPEN SPACE) l �/ AA \ \ \ \, / ,��',�\ j•::. ._� V i OPEN WATER FEATURE �• 1 \J�i � � Yww w I w \ r,� \\/\(/ �W\\\ �. i�P ci �� /A "+ \ �� �J y�j \ / �,/,. \ "" - / KEY PLAN COUNTED AS IMPERVIOUS IN VRRM) I w w 0,60 ;;� 'i ( '• w '+r; /lj V`'� / • ♦♦ _,�, ♦ v \ \ / , �% las/ %',�� P�, / A , �/ �'\4�\ 1 \ \� (\\\\\ A■■ \X\ /�/ i\ ,\W 360 BMP MAINTENANCE ACCESS PATHS $' �\�� \/3�s y /"' ' o \\\ R� y \ \ ♦ ♦♦ • (SEE STORMWATER PLAN SHEETS1j�� FOR GRADING) ROW aFa','/ evr \ / / RO \. • S I / �� .f V /'/ ♦ \. ♦ I\�I \P �\ II \A \ E \ / �Yr \ ,�,�♦ . �^ \ \ '� 12/13 Jl(J/1�j1/ • `r I V �VA\ �d ./� //ll ��i ♦�r�� \ ww ��\ \ ww w♦�♦,a"./��/ ♦♦♦���� ���� \\ `V I., / / \ / ♦ . ti I i u„r ��� 11110 ../`` c BMP H/ .♦ iyyyf S� .•� / \\\� ` /\ `4, \\� ISSUE - \ / r` ` fie• ` ` 1 \ l �. ♦' \\\\�/�. \ \�� >/ / • I , , ■ \ • . I \ j -' M � +�♦� � �;/ ,I �i � �` � ���� ■ .340\�\\�h■ �" // •-■AyA'�lI , \\� REV # DATE DESCRIPTION r Lr \ \\��\..:. n,.: ; ° ;-.ate ►� '� :� 11 yi I l i�i .`t;+:�; � , o h 6� 0° \\\. \ ';.��..�. ;J:+`.'• ^F",.��` ... •/�,� .lam i ,/�, �, .i e ❑ _ — BMPJ2':, : ///• / \\\ mil^ '♦/ �^��\ �� Ewa .;., 1�� .:• `l �........ • \ \ �`` I F `• OF ■■■1� \ _ .,'r Ww�w� \ „-�"`�� ct,t'LTH G 41 r SCOTT C. BLOSSOM m Lic. No. 40287 20 �,.. \ \ SIO NAL Job No: 1005 Drawn By: BCE Date: 03.2.2018 Checked By: soon C. Blossom, P.E. \ STORMWATER EASEMENTS AND BMP ACCESS \ EASEMENTS AND FOREST/OPEN SPACE AREAS SCALE: 1 INCH = 15o FEET N SCALE: 1 INCH = 150 FEET 0' 1501 3001 600' SWM-25