CRDSS_Task1_14-18_ReviewWeatherStations

• Title: CRDSS Task 1.14-18 - Consumptive Use Model - Review of U.S. Bureau of Reclamation Weather Stations and Recommended New Stations
• Description: It was recommended in the Phase I CRDSS Task Memorandum 1.14-1 that the weather station sites be checked for representativeness. This memorandum addresses that recommendation as it pertains to the Gunnison River basin.
• Decision Support - Doc Type: Task Memorandum
• Date: 1/9/1995
• DSS Category: Consumptive Use
• DSS: Colorado River
• Basin: Colorado Mainstem
• Contract/PO #: C153658, C153727, C153752
• Grant Type: Non-Reimbursable
• Bill Number: SB92-87, HB93-1273, SB94-029, HB95-1155, SB96-153, HB97-008
• Prepared By: Riverside Technology inc.

and 6 degrees Fahrenheit lower than Crested Butte, and Taylor Park is only 346 feet higher in elevation
than Crested Butte. Placing a hydrologic divide at Granite Creek was based on the topography.
Hydrologic Unit 14020002, Gunnison County
For this unit, the USBR recommended the consumptive use be weighted 60 percent to the Gunnison
station and 40 percent to the Cimarron station. Based on a review of IDS's map and NOAA precipitation
records, the weighting appears incorrect. Based on a review of the 1965 through 1970 precipitation
records, the irrigated area south of Blue Mesa Reservoir in the vicinity of Powderhorn should be tied to
the Gunnison station; therefore, only the irrigated area west-southwest of Blue Mesa Reservoir should be
tied to the Cimarron station.
Hydrologic Unit 14020003, Gunnison County
For this unit, the USBR recommended only the Cochetopa Creek station. The change recommended in
this memorandum is based upon topography and location of the irrigated land versus weather station
locations and analysis of precipitation. Average annual precipitation at Cochetopa Creek is
approximately 2.0 inches greater than Gunnison.
Hydrologic Unit 14020004, Gunnison County
The USBR recommended changing the station for this unit to Crested Butte from the Paonia station.
This change should not be made because (1) the irrigated area is in the same river basin as Paonia, and
(2) the irrigated area and Crested Butte are on opposite sides of a significant mountain range; therefore,
precipitation patterns are probably significantly different.
Hydrologic Unit 14020005, Mesa County
The USBR recommended changing from Palisade only to Grand Junction (50 percent) and Delta (50
percent). The recommended changes in weather stations are endorsed, but the weight given to each
station needs to be changed. Whether the USBR was recommending the Grand Junction Airport or
Grand Junction 6 ESE weather station is unknown. The 6 ESE station is located at Colorado State
University's Orchard Mesa research station, which is an agricultural environment; therefore, it is
recommended for use in this unit.
Based on the topography and the location of the weather stations and the irrigated area, it is
recommended that the Delta weather station be used only for the Escalante Creek basin. The Grand
Junction 6 ESE should be used for the remaining irrigated area.
Hydrologic Unit 14020006
For this unit, the USBR recommended the Montrose and Olathe station. The Olathe station was a
precipitation only station. It closed in 1993 and did not have continuous weather records from 1975 to
1993. Its use is not recommended.
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A 275 01.09.95 1.14-18 Walter