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HomeMy WebLinkAboutFDP202000001 Correspondence 2020-01-21Albemarle County Floodplain Development Permit No.: ENGINEEMG "NO —RE" CERTIFICATION Community: T' County: AI-1—�'Mi4MLr-5 _State: A. Applicant: V— Date: Telephone: — -00 i Co Engineer: Address: 9L'at7 �csx Telephone: ? i % 51 SITE DATA I. Location y; '/; Section ; Township ; Range Street Address: 5 J -!!MO N 2. Panel(s) No. of NF1P map(s) affected: :7 Q 3 C. [] 2, D2r5 l 3. Type of Development: Filling © Grading [Ef Excavation©. r h Wmv. n Substantial Improv ❑ New ConstructionET OtherC] 4. Description of Development: S. Name of Flooding Source 617- This is to certify that I am a duly qualified engineer licensed to practice in the State of Virginia . It is to further certify that the attached technical data supports the fact that the proposed development described above will not create any increase to the Base Flood Elevations, on the named flooding source, at pub ished cross sections in the Flood Insurance Study for the above community dated Z 4O Sand will not create any increase to the Base Flood Elevations at unpublished cross sections in fb vicinity of the proposed development. Name: Id2RX' Signature: Date: Title: 5. License No.: 5C q (scat) R7-No Rise (Converted to Adobe Forth by State of Virginia) 09-17-19 xx %--1 xv IN -Le ENGINEERING & SURVEYING INC. CERTIFICATION JANUARY 14, 2020 This is to certify that the flood plain development of bridging the perennial stream for driveway access on TAX map 63 Parcel 45 will not impact the flood Plain. The installation of the bridge, the approach ramp and 6 inch crusher run driveway volumes will be offset by the volume of earth removal along the same cross- section path, keeping both cross -sections and volumes equal before construction as well as after construction. The plans and forms are submitted concurrently with this certification. Respectfully submitted, Kurt M. Gloeckner President, P.E & P.L.S BLQECKNER ENGINEERING/SURVEYING INC. ] 980 FOX RuN LANE • CHARLOTTES"LLE, VA. 22901 PHONE: (434)-971-1591 • FAX: (434)-293-7612 - I OF 1 Worksheet 3: Time of concentration (Tc) or travel time (TO Project bi By _VM(y Date _ Location Checked Date Circle one: Present Developed Circle one: Q� Tt through subarea NOTES: Space for as many as two segments per flow type can be used for each worksheet. Include a map, schematic, or description of flow segments. Sheet flow (Applicable to Tc only) Segment ID C3 I. Surface description (table 3-1) ............ W 2. Manning's roughness coeff., n (table 3-1)- 3. Flow length, L (total L < 300 ft) .......... ft pJ 4. Two-yr 24-hr rainfall, P2 - in 4.0 5. Land slope, a ft/ft 43.1% 6. Tt = 0.007 (nL)0.8 Compute T...... hr Q,� �C # �•J1� P .5 sO t 2 Shallow concentrated flow Segment ID 15 " G 7. Surface description (paved or unpaved) ..... B. Flow length, L ......................... ft Z Q 9. Watercourse slope, s ....................... ft/ft 10.2 5 10. Average velocity, V (figure 3-1) ........... ft/9 l� 11. T L O l t 3b00 V Compute Tt •..... hr �� + Channel flow Segment ID 12. Cross sectional flow area, a ft2 13. Vetted perimeter, pw ....................... ft 14. Hydraulic radius, r = g Compute r ft P w 15. Channel slope, s ft/ft 16. Manning's roughness coeff., n ...... 0.... ,.. I7. 1.49 r2/3 s1/2 V n Compute V ....... ft/s 3. 1 IS. Flow length, L ...............0............. ft ' 0O 19. L Tt " 3600 V Compute Tt ...... hr �•� + = Q k r 20. Watershed or subarea Tc or Tt (add Tt in steps 6, 11,' and 19) hr (210-VI-TR-M, Second Ed., June 19M) D-3 Y1`ornSUCC6 .5: AtUBUAA CUl-VI; I111MUCI' illlU FUAIUAA Project_ &--t �FE' i''Cre) AY" Date 1 18 %-Q Loca t ion Z ' cA Checked Date Circle one: Present Developed I. Runoff verve ntun11rr (CN) % Soil name Cover description Area Product and CN --� of hydrologic (cover type, treatment, and CN x area group hydrologic condition; e:r Qacres percent impervious; at 0mi2 unconnected/connected impervious ..0 0 Z (appendix A) area ratio) lr, 'LM © Q F— Use only one CN source per line. a Totals CN (weighted) - total product � _ s Use CN total area ; 2. ' Runoff Frequency .............................. yr Rainrall, l' (24-huur) .................. in Runoff, Q in (Use P and CN with table 2-1, fig. 2-1, or eqs. 2-1 and 2-4.) u storm 11 Storm 12 storm 13 10 D-2 (210-V1-TR-55, Second Ed., June 1986) _ r, I17r2= Web Soil Survey - us .9117'. MA Contazt Us 5'ab5cib. Ambived Soil Surveys 5o11Survey Status Glasney I Preferanee_k I LiM Legout I Help A A Area Of Interest MI ' �011 MBF Soil Data Explorer Download Soils Data Shopping Cart (Free) P"rftbk% vm&M in MMwPbw SearchSwat} Map Map UPA Legerid Albemarle County, Virginia (vAoo3) Albemarle County, Virginia (VA003) map Unit HIM Unit Name svmboj Acres in AOI percent of AOI 13E Catoctin silt 77.5 8.9% loam, 25 to 45 percent slopes, very stony 23B Yadkin day 7.3 0.8% loam, 2 to 7 percent slopes 23C Yadkin day 1.0 0.1% loam, 7 to 15 percent slopes 58B Myersville silt 16.3 1.9% loam, 2 to 7 percent slopes 58C Myersville silt 0.1 0.0% loam, 7 to 15 percent slopes 58D Myersville silt 31.7 3.6% loam, 15 to 25 percent slopes SSE Myersville silt 16.6 1.9% loam, 25 to 45 rOIA I Accessibility Statement I Privacy Policy j Non -Discrimination Statement I Information Quality I USA-gov I White House �-A 4A it 6 F_ CA 73 hftps:flwebwilsurvey.9c.egm.usft.gov/App/webSoliSurvey.aspx 1/1 Workwheet 4: Graphical Peak Discharge method Project AW,*z r By Date Location - Checked Date Circle one: Present Developed 1. Data: Drainage area - % - I __ m12 (acres/640) Runoff curve number .... CN - 7.3 (From worksheet 2) Time of concentration .. Te a 4n,70 hr (From worksheet 3) Rainfall distribution type - Sri..,-_ (1, IA, I, III) Pond and swamp areas spread throughout watershed R percent of Ain( acres or mil covered) 2. Frequency .......................*.**...• 3. Rainfall, P (24--hour) ................... 4. Initial abstraction, I a ......., (Use CN with table 4-1.) 5. Compute Ia/P •..........................• Storm #1 Storm #2 Storm #3 yr 10 3 in in o.74 6. Unit peak discharge, qu csm/in (Use Tc and Ia/P with exhibit 4-7M) 7. Runoff, Q ............................... (From worksheet 2). 8. Pond and swamp adjustment factor, Fp .... (Use percent pond and swamp area with table 4-2. Factor is 1.0 .for zero percent pond and swamp area..) 9. Peak discharge, qp ...................... (where qp - quAmQ g) W 10. 1"o in efs Q w V-- ► A _ -r©. (210-VI-TR-55, Second Ed., June-1986) % 1� 5 s"r Vet WmA-rr . 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