HomeMy WebLinkAboutWPO201600069 Calculations 2020-12-11THE VUE
STORMWATER MANAGEMENT CALCULATIONS PACKET
ASSOCIATED WITH WPO 201600069 AMENDMENT #2
SCOTT R. LINSZ
No. 35791 4t�
11/ 17/20 w4
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Date of Calculations
NOVEMBER 17, 2020
PREPARED BY:
COL-LINS F-P4 INEERING
200 GARRETT STREET, SUITE K
CHARLOTTESVILLE, VA 22902
434.293.3719 PH
434.293.2813 FX
www.collins-engineering.com
Soils Mapping (Source: NRCS Web Soil Survey Online Database)
Soils Table (source: NRCS Web Soil Survey Online Database)
Albemarle County, Virginia (VA003)
Map percent of
Unit Map Unit Name AO1
symbol
17 Craigsville loam, 65.30/u
0 to 2 percent
slopes,
frequently
flooded
37D3 Hayesville clay 34.7%
loam, 15 to 25
percent slopes,
severely eroded
Totals for Area of 100.00/0
Interest
The NRCS web soil survey defines this development's soils as predominantly having a hydrologic group type A.
Precipitation Data
(Source: NOAA's National Weather Service, Hydrometerorological Design Studies Center, Atlas 14
Point Precipitation Frequency Estimates)
Map
Terrain
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6 ar0a'nrn Bran
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100m Jarman. Gap Rd
J"d,
POINT PRECIPITATION FREQUENCY (PF) ESTIMATES
WITH 90% CONFIDENCE INTERVALS AND SUPPLEMENTARY INFORMATION
NOAA Atlas 14, Volume 2, Version 3
I PDS-based precipitation frequency estimates with 90 % confidence intervals (in inches)' I
3.08 3.72 C74 5.59 6.84 7.97 9.09 10A 12.3 140
24.Ir (2.77-344) 1 (3.354.16) 1 (4.255.30) 1 (5.005.24) 1 (6.08-7.62) 1 (6.9".80) 1 (7.90.10.1) 1 (8.W11.5) 1 (10.5-13.7) 1 (11.7-15.6)
Water Quality Calculations Associated with the Vacation of a Portion of
the Existing, Recorded SWM Forest & Open Space Easement
NOTEWORTHY WATER QUALITY ITEMS:
1. This WPO plan accounts for the vacation of a portion of the existing, recorded SWM Forest and Open
Space easement. The following calculations depict the water quality credit that is associated with the
SWM Forest and Open Space easement area being vacated. This credit, which is being removed with
this plan, will be mitigated via the best management practice of purchasing nutrient credits.
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