HomeMy WebLinkAboutSP202200001 Study 2023-03-23L I N E + G R A D E
C I V I L E N G I N E E R I N G
MEMORANDUM
TO: Scott Clark �F ALTN OF
Albemarle County (r.)KE
FROM: Kendra Moon, PE NDR C�MOON
Line and GradeLic. No. 63650
DATE: March 14, 2023 �t�k
RE: Misty Mountain Camp Resort S�ONAL 1,
Site Specific Groundwater Use and Recharge
Scott,
Below are revised groundwater use calculations for Misty Mountain Camp Resort. These
calculations are specific to the Misty Mountain property, rather than taking into account the
entire watershed.
Calculations are based upon the most intensive use at full build -out, assuming 53 new
campsites and 3 new cabins in addition to the existing 16 cabins, 105 campsites, and 2 dwelling
units. These calculations take into account the decreased recharge due to increased impervious
area, and the recharge that occurs from well water that is disposed of into drainfields and
ultimately back into groundwater. Assumptions used in these calculations result in a
conservative estimate.
The calculations for the site show that the groundwater recharge at full build -out will exceed
the groundwater withdrawal on site, with a recharge rate of 43,283 GPD and a withdrawal rate
of 32,220 GPD. Based on these calculations, there is no foreseeable impact on the groundwater
supply for neighboring parcels.
Please contact me with any questions.
Sincerely,
LINE+GRADE
Kendra G. Moon, PE
LINE i-
GRADE
CIVIL ENGINEERING
113 4- St. NE, STE 100
CHARLOTTESVILLE, VA 22902
TEL: (434) 262-0169
LINE-GRADE.COM
Misty Mountain Camp Resort
Groundwater Use
March 14, 2023 1 Page 2
Assumptions
Annual regional precipitation: 46.8 inches
Percentage of precipitation contributing to groundwater recharge, subtracting runoff and
evapotranspiration (up to 33%): 15%
Annual regional groundwater recharge: 7.02 inches
Water withdrawal per day: 180 gal per day per unit
Percentage of water withdrawal contributing to recharge via disposal in drainfield (ranges up
to 95%): 75%
Calculations
Average regional daily groundwater recharge (7.02 in per yr / 365 days per yr / 12 in per ft):
0.0016 ft
Daily recharge per acre (0.0016 ft X 43,560 sf per acre): 69.8 cf recharge per acre
Gallons recharge per day per acre (69.8 cf recharge per acre X 7.48 gal per cf): 522 gal
recharge per day per ac
Gallons per day natural recharge to site (522 gal recharge per day per ac X 47.11 ac): 24,602 1
gal recharge per day T
Gallons per day natural recharge lost due to total proposed impervious cover on site (522 gal
recharge per day per ac X 10.5 ac): 5,483 gal lost per day
Estimated site water withdrawal per day at full build -out (180 gal per day per unit X 179 units): wimms
32,220 gal used per day
Estimated water withdrawal contributing to groundwater recharge via disposal in drainfield Nil
(32,220 gal per day X 75%): 24,165 gal recharge per day
The result is a conservative estimate of a surplus of 11,063 gal per day L I N E
GRADE
CIVIL ENGINEERING