HYDRO31018

• Permit No: M2003091
• IBM Index Class Name: Hydrology
• Doc Date: 7/25/2005
• Doc Name: water supply plan
• From: office of the state engineer
• To: dmg
• Media Type: D
• Archive: No

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STATE OF COLORADO
OFFICE OF THE STATE ENGINEER
Division of Water Resources
Department of Natural Resources
1313 Sherman Sveet, Room 81B
Denver, Colorado 80203
Phone [phone]
FAX [phone]
www.watecstate.co.us
Mr. Richard T. Raines, P.H.
Applegate Group, Inc. /
1499 West 120a' Ave, Suite 200
Denver, Colorado 80234-2759
July 20, 2005
Re: Duckworth Pit, Substitute Water Supply Plan
DMG File No. M-03-091 /
Section 16, T2N, R68W, 6`~ P.M.
Water Division 1, Water District 6
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Bil! Owens
Governor
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Executive Director
Hal D. Simpson, P.E.
RECEIVED s~~ EnBneer
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aVision •f Minerels and Geology
Approval Period -July 20, 2005 through June 22, 2006 (October 31, 2006 if extended)
Dear Mr. Raines:
This letter is in response to your application of March 17, 2004 requesting a substitute
water supply plan (SWSP} for a sand and gravel pit to be operated by Lafarge West, inc.
("Applicant") in accordance with 37-90-137(11), C.R.S. The Applicants shall be responsible for
compliance with this plan, but the State Engineer's Office may also pursue the landowner, for
eventual compliance. The required fee of $1,343 for the SWSP has been paid.
This plan describes the proposed water uses through October 2006 for this new mining
operation. The proposed plan anticipates a maximum annual consumptive use of 26.9 acre-
feet for up to 1.1 acres of exposed dewatering trench and sediment pond. Because this is a
new mining operation, no groundwater was exposed within the permit boundary prior to January
1, 1981.
You have provided a monthly breakdown of the maximum annual depletions totaling 2.8
acre-feet of evaporative loss from a maximum of 1.1 acres of exposed groundwater, 2.0 acre-
feet of water used and consumed for dust control, and 22.1 acre-feet of water lost with the
mined product.
This current plan anticipates dry mining of the Duckworth Pit by dewatering. The operator
proposes to continuously dewater and dry mine the site. Should the dewatering cease, the
maximum exposed groundwater surface area will be no greater than 37.0 acres with an annual
evaporative loss of approximately 94.5 acre-feet. The Applicant has committed more than 112
acre-feet of consumptive use credit from 1.0 share of the Smith and Emmons Ditch (67.4 acre-
feet per year) and 1.0 share of the Rural Ditch (45.4 acre-feet per year) to offset the evaporative
depletions that would occur annually should dewatering cease.
The mining operation is located more than 100 feet from the Boulder Creek. The
Applicant has provided a monthly schedule of lagged depletions to the river system resulting from
the operational losses at this site. The proposed replacement amount (2.4 acre-feet for July 2005
through October 2005 and 14.8 acre-feet for November 2005 through October 2006) represents