2016-01-14_HYDROLOGY - M1981022

• Permit No: M1981022
• IBM Index Class Name: Hydrology
• Doc Date: 1/14/2016
• Doc Name: Substitute Water Supply Plan
• From: DNR Water Resources
• To: DRMS
• Email Name: MAC
• Media Type: D
• Archive: No

DEPARTMENT OF NATURAL RESOURCES
DIVISION OF WATER RESOURCES
January 14, 2016
Mr. Todd Williams
Williams and Weiss Consulting, LLC
5255 Ronald Reagan Blvd., Ste. 220
Johnstown, CO 80534
RE: G.L. Substitute Water Supply Plan (WDID 0302518)
G.L. Gravel Pit, DRMS No. M-1981-022 (WDID 0303008)
NW1/4 Section 3, T7N, R69W, 6th P.M.
Water Division 1, Water District 3, Larimer County
Approval Period: January 14, 2016 through May 31, 2016
Contact Phone Number for Mr. Williams: [phone]
John W. Hickenlooper
Governor
Mike King
Executive Director
Dick Wolfe, P.E.
Director/State Engineer
RECEIVED
JAN 14 2016
DIVISION OF RECLAMATION
MINING & SAFETY
Dear Mr. Williams:
Your letter dated April 15, 2015 requesting renewal of the above referenced substitute
water supply plan to cover depletions caused by an existing gravel mining operation has been
reviewed. The required fee of $257 for the renewal of this substitute water supply plan has been
submitted (receipt no. 3669300). The original plan was approved on March 26, 1993 and was
most recently renewed on June 27, 2014 for operations through May 31, 2015.
Plan Operation
Mining at the G.L. Pit has been completed. The original reclamation plan included
constructing a lined water storage reservoir. In February 2011, the Division of Mining,
Reclamation, and Safety (DRMS) approved Technical Revision 02 (TR -02) changing the
reclamation plan to eliminate the lined reservoir and instead backfill all ground water exposure.
Based on November 2012 backfilling operations the exposed ground water was reduced from
2.3 acres to 1.67 acres. Additional backfilling of the site occurred over the past year. The
Applicant used a Global Positioning System (GPS) receiver on April 10, 2015 and marked the
remaining exposed surface area boundaries. The current exposed water surface at the site is
0.91 acres as shown on the attached Map 2. For the purpose of projecting depletions, this
SWSP assumes the exposed ground water will remain at 0.91 acres for the entire SWSP
approval period though backfilling is planned to occur. Note that all ground water at this site was
exposed after December 31, 1980.
Depletions
The only consumptive use associated with the G.L. Pit site will be from evaporation of
exposed groundwater. As mentioned above the current exposed surface area at the G.L. Pit is
0.91 acres. Net evaporative depletions were calculated using a gross annual evaporation of
39.0 inches from the exposed water surface, with a credit of 8.9 inches for effective
precipitation. The total evaporative depletions from the 0.91 acre pond are therefore 2.31 acre-
feet per year.
The centroid of the remaining ground water exposed at the G. L. Pit site is located
approximately 1,900 feet from the Cache La Poudre River, thus depletions were not assumed to
Office of the State Engineer
1313 Sherman Street, Suite 818 • Denver, CO 80203 • Phone: [phone] • Fax: [phone]
www.water.state.co.us