2011-03-22_HYDROLOGY - M1994005

• Permit No: M1994005
• IBM Index Class Name: HYDROLOGY
• Doc Date: 3/22/2011
• Doc Name: SEO complience letter
• From: Wright Water Engineers, Inc.
• To: DRMS
• Email Name: GRM
• Media Type: D
• Archive: No

Table 1
Evaporation calculation for site near Colona, Colorado (elev. 6200 ft)
United Companies - Colona Gravel Pit
Groundwater exposed 4.4 acres (based on current measurements)
Gross Evaporation 43 inches (from NOAA Technical Report NWS 33)
Precipitation Station Montrose 2
e.
I?
6
S
ober 7.0 3.01 1.31 0.92 2.09 0.17 50.31 0.17 0.77
Nember 4.0 1.72 1.19 0.83 0.89 0.07 37.18 0.07 0.33
Dember
! 3.0 1.29 0.66 0.46 0.83 0.07 27.19 0.00 0.00
January 3.0 1.29 0.66 0.46 0.83 0.07 25.72 0.00 0.00
February 3.5 1.51 0.64 0.45 1.05 0.09 31.81 0.00 0.00
arch 5.5 2.37 1.15 0.81 1.56 0.13 39.76 0.13 0.57
April 9.0 3.87 1.17 0.82 3.05 0.25 48.16 0.25 1.12
May 12.0 5.16 1.26 0.88 4.28 0.36 57.31 0.36 1.57
une 14.5 6.24 0.82 0.58 5.66 0.47 66.44 0.47 2.08
ul 15.0 6.45 1.49 1.04 5.41 0.45 72.11 0.45 1.98
August 13.5 5.81 1.77 1.24 4.57 0.38 69.80 0.38 1.67
Se tember 10.0 4.30 1.63 1.14 3.16 0.26 61.80 0.26 1.16

Footnotes:
(1) From SEO's Guidelines (2/28/95) for sites with elevation less than 6,500 ft.
(2) Annual value from NOAA Technical Report NWS 33.
(3) Average annual precipitation data from NOAA recording stations at Montrose 2 (1982-2006) and Ridgway (1982-2006) averaged.
(4) Equals Column (3) x 0.70
(5) Column (2) - Column (4)
(6) Column (5) / 12
(7) Average monthly temperature at the Montrose 2 Climate Station
(8) If Column (7) is less than 32 then equals zero, if greater than 32 equals Column (6)
(9) Column (8) x number of exposed groundwater surface acres.
P:\061-052\000 - Colona\DRMS\
DRMS Ammended Tables March 2011_WCR_with_ice
Wright Water Engineers, Inc.
March 2011
Des by: WCR
Ckd by: PRF