HYDRO25279

• Permit No: M1978210
• IBM Index Class Name: Hydrology
• Doc Date: 3/20/2006
• Doc Name: Substitute Water Supply Plan
• From: OSE
• To: DMG
• Permit Index Doc Type: Correspondence
• Media Type: D
• Archive: No

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0~ STATE OF COLORADO
OFFICE OF THE STATE ENGINEER oF.~~
Division of Water Resources RO~
Department of Natural Resources »e ~ ~
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1313 Sherman Street, Room 818
Denver, Colorado 80203 ~ `lave `+
Phone [phone]
FAX [phone] / March 9, 2006 /'~ V ED Bill Owens
www.wa[er.state.co.us 'v// RE'\,/~~ Governer
Russell George
~p Executlve Director
Mr. Steve Nguyen, P.E. ~ AR 2 a ~~~ Hal D. Simpson, P.E.
Clear Water Rights, Inc. srate En nee`
13228 Shadow Canyon Trail Nrisioa~t MklerelssndGedaSY ~
Broomfield, Co 80020 /
RE: Substitute Water Supply Plan, Geisert Pit, M-78-210
Section 31, T6N, R65W, 6th P.M.
Water Division 1, Water District 3
Approval Period: April 1, 2006 through March 31, 2007
Contact Phone Number for Mr. Steve Nguyen: 303-929-0758
Dear Mr. Nguyen:
We have reviewed your letter of January 10, 2006, requesting renewal of the above referenced
substitute water supplyplan to cover depletions caused by an existing mining operation. Weld County operates
this site to produce aggregate for road base and public works construction projects. The required fee of $217.00
for the renewal of this substitute supply plan has been submitted. The original supply plan was approved on
March 25, 1994 and it was most recently renewed on May 2, 2005.
Based on an aerial photo taken in July 2004, the total exposed surface area at this site is 42.6 acres.
According to the information submitted, 6 acres of water surface was exposed within the reclamation permit
boundary prior to January 1,1981. This results in 36.6 acres of exposed surface area requiring replacement
of depletions from evaporation. The anticipated net depletion for this plan is 113.5 acre-feet per year. No
dewatering is provided or sought under this plan.
You have provided a monthly bn:akdown of the annual depletions totaling 107 acre-feetof evaporative
loss, 2 acre-feet of water used and consumed for dust control, and 4.4 acre-feet of water lost with the mined
product (150,000 tons of aggregate). No phreatophyte credit has been applied to this plan. In previous plans
for the Geisert Pit, instantaneous depletions to the river system were assumed, underthe assumption that the pit
is located within 100 feet from the Cache La Poudre River. However, based on the aerial photo of July 2004 it
was determined that the average down-gradient extent of the exposed groundwater to be approximately 300
feet from the Cache La Poudre River. Therefore, a stream depletion model was used to determine the lagged
depletions to the Cache La Poudre River. The following parameters were used in the model: transmissivity (T)=
120,000 gallons per day per foot, specific yield (SY)= 0.2 (which is typical for an alluvial aquifer), the
distance of the exposed ground water to the river=300 feet, and the location of the parallel impermeable
boundary was estimated to be 2,700 feet from the stream (based on the USGS Geologic Map of the
Bolder-Fort Collins-Greeley Area, Colorado).
The source of replacement water to be used for this plan is a lease of 113.5 acre-feet of reusable
effluent from the City of Greeley. Weld County has a perpetual lease with the City of Greeley for the right to
use up to 300 acre-feet per year of the Greeley's reusable effluent. A copy of the lease agreement with the
City of Greeley for 113.5 acre-feet of fully consumable effluent from Greeley's wastewater treatment plant