Wyoming State Water Plan, Wyoming Water Development Office
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Bear River Basin Water Plan
Technical Memoranda

SUBJECT: Appendix J
Municipal Water Use - Town of Cokeville

PREPARED BY: Bear River Basin Planning Team


Introduction: The Town of Cokeville is a rural community situated near the Wyoming- Idaho border in Lincoln County, Wyoming. Cokeville presently has a population of approximately 500 residents (160 connections), all of which are served by the town's municipal water system. The community historically received its water from a series of three springs (Cokeville, Kenyon, and Wyman) located 2.5 miles northeast of town in the Spring Creek drainage as shown on the location map on the next page. The combined summertime capacity of the springs was approximately 1200 gpm.

In the mid 1990's, serious questions were raised about the EPA classification of the springs and the town's ability to protect their water sources from surface water influence. Ultimately, it was decided to abandon the springs as a drinking water source and construct groundwater wells in the same general vicinity.

Service Area Population: 497 (160 connections)

Water Supply: Cokeville no longer uses the their springs as a municipal supply. Three wells were drilled in the immediate vicinity (and in the same aquifer) as the Cokeville / Kenyon Springs located 2.2 miles east of town in the Smiths Fork / Spring Creek Drainage as follows:

All three wells are drilled into the Cretaceous Thomas Fork Formation.


Cokeville Well No. 2


Cokeville Well No. 3

Raw Water Transmission: Well water is disinfected at the well head and pumped directly to the Cokeville's tanks through a 14-inch Asbestos Cement transmission pipeline. A second parallel 8-inch Cast Iron Pipe was abandoned in 1994. Water is in turn delivered to the town through a 10-inch cast-iron main extending from the tanks to the west end of Main Street.

Water Treatment: Disinfection (Gas Chlorination)

Finished Water Storage: Two partially buried concrete storage tanks, each with a capacity of 250,000 gallons. The tanks are located adjacent to each other on a hill immediately east of town.

Wastewater Treatment / Discharge: Aerated lagoon system. Treated wastewater discharges directly into the Bear River Channel. Discharge is measured using a V-notch weir. The accuracy of the weir is highly questionable. There is a sewage lift station immediately upstream of the lagoons. Ultrasonic meter readingstaken on July 21, 2000 indicate an average pump delivery capacity of 150 GPM. Based on pump hour records for the past 12 months, annual lagoon wastewater inflows are approximately 143 acre- feet. This reflects an average inflow of approximately 88 GPM or 0.352 AFD.

Monthly Water Rates: $17.50/month flat rate. Monthly bill for the use of 20,000 gallons = $17.50.

Annual Water Use: (based on July 1999 – July 2000 well meter records)

Per Capita Use: (average annual gallons per capita per day)

Recorded Peak Day Demand:

	Date		         Gallons 	Per capita use

	August 31, 1985	        859,000	          1728 	
	July 14, 1986		1,120,000	  2254
	July 14, 1987		1,152,000	  2318
	July 22, 1989		1,200,700	  2416
	July 11, 1995		1,240,000	  2495
Water Supply System Capacity: 1100 gpm = 1.584 MGD = 2.45 CFS = 4.86 AFD (Based on well pumping capacity)

Municipal Water Rights:

Surface Water Source:		Priority		Appropriation

Kenyon & Wyman Springs	 	Apr 21, 1913		1.5 CFS
Cokeville Spring		Dec 21, 1922		*
Kenyon Spring		     	Oct 14, 1983		0.6555 CFS
Cokeville Spring		Oct 14, 1983		0.6555 CFS

						TOTAL	2.8110 CFS

*  supplemental to original Kenyon and Wyman spring filing.  Total appropriation not to 
exceed 1.5 CFS (2.98 AFD).  Spring sources are not presently used by the town.

Well Source:	   Permit Number	      Priority	        Appropriation

Cokeville No. 1	             N/A - Test Well Only
Cokeville No. 2	   UW110471		      June 12, 1998      450 GPM
Cokeville No. 3	   UW 110472 	              June 12, 1998      700 GPM	

						     TOTAL      1150 GPM
 						               (2.56 CFS)
Permits are subject to Amended Bear River Compact of 1980. Bear River Commission Depletion Estimates for municipalities are about 73 gallons per capita per day. A total allocation of 45 acre feet of depletion is attributed to Cokeville for all post-1976 water development including springs, wells, and surface diversions.

Planned Future System Changes:

The Town of Cokeville may wish to use their springs as sources for secondary irrigation water in the long-term future. This option would significantly reduce domestic summertime water demands. It would do nothing, however, to reduce Cokeville's overall consumption.

References:

    Forsgren Associates, p.a., Cokeville Water Supply Level II Study, November 1993

  1. Jack Noblitt & Associates, p.c., Cokeville Water System Evaluation, September 1983.

  2. Johnson-Fermelia Co., Inc., Level I Report - Cokeville Water Supply Study Project, November 1991.

  3. Huntingdon Chen-Northern, Report of Geotechnical Investigation- Cokeville Reservoir Tank Site, October 1992.

  4. TriHydro Corporation, Phase I report of Groundwater Alternatives Investigation - Cokeville, Wyoming, August 1992.

  5. TriHydro Corporation, Phase II Report of Well Construction and Testing Program - Cokeville, Wyoming, September 1993.