HYDRO30212

• Permit No: M1979195
• IBM Index Class Name: Hydrology
• Doc Date: 9/26/2003
• Doc Name: Substitute Water Supply Plan
• From: OSE
• To: Environment Inc.
• Media Type: D
• Archive: No

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STATE OF COLORADO
OFFICE OF THE STATE ENGINEER
Division of Wa[er Resources
Department of Natural Resources
1313 Sherman Street, Room 818
Denver, Colorado 80203
Phone [phone]
FAX [phone]
vrww,wa[ecstate.co.us
September 26, 2003
Stevan L. O'Brian
Environment, )nc.
7985 Vance Drive, Suite 205A
Arvada, CO 80003 /~f~
Re: Substitute Water Sup Ip y plan, Road Runne~est II Pit (M-79-195)'"
Sections 3 & 4, Township 2 South, Range 67 West, 6th P.M.
Water Division 1, Water District 2, Adams County
Dear Mr. O'Brian:
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Bill Owens
Governor
Greg E. Walther
Executlve Director
Hal D. Simpson, P.E.
State Engineer
This letter is in response to your application for a substitute water supply plan for the Road
Runner Rest II Pit in accordance with C.R.S. §37-90-137(11). The required fee for the substitute water
supply plan has been submitted.
According to the monthly breakdowns provided in your letter of September 5, 2003, the
anticipated net depletions for this plan are 51.6 acre-feet for evaporation from 20 acres of groundwater
exposed after December 31, 1980, 7.36 acre-feet of water lost with the mined product (based on
mining of 250,000 tons/year), and 2 acre-feet used for dust suppression. According to the information
submitted, no groundwater was exposed within the reclamation permit boundary prior to January 1,
1981. Depletions from evaporation and operational losses are assumed to occur instantaneously
based on the edge of the ground water pond being located within 100 feet of the South Platte River.
No phreatophyte credit has been applied to this plan. The monthly depletion and replacement
requirements are found on the attached table.
You have estimated gross annual evaporation for this site to be 41 inches, however based on
our review of the NOAA Technical Report NWS-33, gross annual evaporation for this site has been
estimated to be 44 inches. Also, in accordance with your letter of September 25, 2003, the exposed
pond surface area has been reduced to 19 acres. This results in a net annual evaporation amount of
2.77 acre-feet per year, or 52.6 acre-feet for the 19-acre ground water pond surface.
Presently, the pit is being dewatered to maintain an exposed pond area of no more than 19
acres. If dewatering was stopped, an exposed groundwater surface of approximately 100 acres would
result. In the event the dewatering pumps fail or are stopped for any reason, depletions resulting from
evaporation from up to 100 acres of pond surface will be replaced using water teased from Denver
Water ("Denver") pursuant to the letter dated May 14, 2002 from Denver to Sandra A. Snodgrass on
behalf of Suburban Sand and Gravel Company ("Suburban"). The letter indicates that in the event that
the pit fills with water, Denver agrees to lease water on the understanding that Suburban will dewater
the pit as quickly as reasonably possible, and the excavation would not be allowed to remain full for an
extended period of time.
The source of replacement water for this plan consists of a lease from Denver of 65 acre-feet
of nonpotable replacement water (in addition to the water available pursuant to the May 14, 2002