Nevada Water Science Center

Aquifer Tests

Contact Information

Phil Gardner
Groundwater Specialist
Phone: (775) 887-7664


Mailing Address
Nevada Water Science Center
2730 N. Deer Run Rd.
Carson City, NV 89701


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Carson Valley

Primary Investigator: Doug Maurer

Well Data

Local Name Altitude Uppermost
Primary Aquifer Transmissivity
385444119453301 Ranchos Rocky Terrace 4761 240 390 ALLUVIAL FILL 5900


Aquifer Test

All Aquifer Test Files (zip)

Ranchos Rocky Terrace

Aquifer Test (pdf)

Single-well step-drawdown and constant-rate tests of the well were conducted by Humboldt Drilling and Pump Company, Inc., of Winnemucca Nevada, in conjunction with RO Anderson Engineering, Inc., of Minden, Nevada. The well is completed in the basin-fill aquifer of Carson Valley, Nevada. The Gardnerville Ranchos General Improvement District currently calls this well "number 9". Copies of the time-drawdown and pump data were obtained from files of the Gardnerville Ranchos General Improvement District (Bob Spellburg, written commun., 2005). Results of the aquifer test will be used in the development of a numerical ground-water flow model in Carson Valley, project # 9705-BPS01. Specifically, the estimated transmissivity will be used to develop a relation between transmissivity and specific yield. The relation will then be used with data from driller's logs to develop a preliminary distribution of transmissivity for the valley.

Rates for the step-drawdown test were varied from 508, to 752, and 1001 GPM for periods of about 3 hours on 05/25/05. The pump rate during the constant-rate test was 1,000 GPM for a period of 48 hours on assumed dates from 5/26/05 to 5/28/05. Data sheets for the constant-rate test do not list the test date and the test is assumed to have taken place the day after the step-drawdown test. Flow rates were measured with a totalizing meter, and flow was routed from a likely nearby pit to a man-made ditch and to a field of unknown distance from the well. The methods of water-level measurement and pre-test water-level trends are not known. The well was reported completed on 5/11/05, and development of the well likely took place a relatively short time prior to the test period.

Results of the step-drawdown test indicate a hydraulic conductivity and transmissivity of 20 ft/day and 7,000 ft2/day, respectively, whereas results of the constant-rate test indicate a hydraulic conductivity and transmissivity of 18 ft/day and 7,500 ft2/day, respectively, fairly similar values.



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