HYDRO30170

• Permit No: M1989044
• IBM Index Class Name: Hydrology
• Doc Name: Substitute Water Supply Plan
• From: OSE
• To: Blatchley Associates Inc.
• Permit Index Doc Type: Correspondence
• Media Type: D
• Archive: No

STATE OF CQL~~~ADO
OFFICE OF THE STATE ENGINEER ~ ~ ov•co~
Division of Water Resources v ~gJ ~ ~~_
Department of Na[ural Resources Y ~ / „e
1313 Sherman Street, Room 818 J » ~
Denver, Colorado 80203 AU9USt 3, 2006 ~yy \ «» I~»
Phone [phone] • ,
FAX [phone] Bill Owens
www.watecstate.m.us Goexnwr
Mr. William M. Blatchley B"~0
Blatchle Associates, Inc. Exec~we Dnec[or
y Hal D. Simpson, P.E.
2525 South Wadsworth Blvd., #306 Staoe EnQneer
Denver, Co 80227
Re: Clare Gravel Pit, Substitute er Supply Plan
DMG File No. M-1989-044
Section 1, T13S, R71W of the 6~' P.M.
Water Division 1, Water District 23 /
Approval Period: May 1, 2006 through Apri130, 2008 /
Contact Phone Number for Mr. William Blatchley: 303-989-6932
Dear Mr. Blatchley:
This letter is in response to your application of December 14, 2005 requesting a substitute
water supply plan ("SWSP") for a sand and gravel pit owned by Clare Corporation, Inc. and
operated by A. C. Concrete & Materials in accordance with 37-90-137(11) C.R.S. The required
fee of $1,343 for the substitute water supply plan has been paid.
This SWSP describes the proposed water uses at the historically mined Clare Pit during
the next two years of this operation. The proposed SWSP anticipates a maximum year net
depletion of 1.88 acre-feet for up to 3.5 acres of exposed groundwater surface during the
approval period. According to the attached affidavit by Harold E. Clare, II a portion of this pit
(0.7 acres) exposed groundwater prior to January 1, 1981 and, as such, the evaporation from
that portion of the pit does not require augmentation. Depletions from the mining of this
existing operation will accrue to Twin Creek.
You have provided a monthly breakdown of the maximum year annual depletions
totaling 0.88 acre-feet of evaporative loss from a maximum of 2.8 acres of groundwater
exposed after January 1, 1981 and 1.0 acre-feet of water lost with the mined product.
Phreatophyte credit has been applied to this plan for the willows which previously occupied the
pit area along the Twin Lake riparian corridor. No dewatering is provided or sought under this
SWSP.
Although the water supply report, estimates the gross evaporation rate at 34 inches, for
the purposes of this SWSP, gross annual evaporation using NOAH Technical Report NWS-33,
Evaporation Atlas for the Contiouous 48 United States was determined to be approximately 40
inches. Therefore, using the State Engineer's General Guidelines for Substitute Supply Plans
for Sand and Gravel Pits, the State Engineer has determined the net depletions for this SWSP
to be 2.11 acre-feet for the 2.8 acres of water surface to be exposed at the site. Based on the
above-mentioned guidelines, the net evaporation for the 2.8 acres was determined to be 1.11
acre-feet after applying the 4.02 acre-feet per year of phreatophyte credits for the sub-irrigated
willows and grass. Computation of evaporation under this plan was also reduced during the ice