BOARD00039 ‎(2)‎

• Board Meeting Date: 9/20/2006
• Description: WSP Section - Consumptive Uses and Losses and High-Altitude Crop Coefficients
• Board Meetings - Doc Type: Memo

ST A TE OF COLORADO

.

Colorado Water Conservation Board

Department of Natural Resources
1313 Sherman Street, Room 721
Denver, Colorado 80203
Phone: [phone]
FJlX:[phone]
WWW.cwcb5tate.co.us

MEMORANDUM

Bill Owens
Governor

TO:

Colorado Water Conservation Board Members

Russell George
Executive Director

FROM:

Ray Alvarado, Andy Moore
Water Supply Protection Section

Rod Kuharich
CWCB Director

Dan McAuliffe
Deputy Director

DATE: September 6,2006

SUBJECT: Agenda Item 21, September 19-20,2006 Board Meeting-
Consumptive Uses and Losses and High-Altitude Crop Coefficients

Introduction

.

This is an update from the July 2006 Board Meeting, at which the Board directed Staff to contact the
appropriate water districts in the Colorado River Basin and inform them of the memo presented at the
July meeting regarding the calculation of high-altitude crop consumptive use. The memo from the July
meeting is attached for reference.

Discussion

Since the July Board Meeting, letters were sent to the Colorado River Water Conservation District, the
Upper Gunnison River Water Conservancy District, the Uncompahgre Valley Water Users
Association, and the Southwestern Water Conservation District. These letters described the effort
being undertaken by Staff concerning the calculation of crop consumptive use on the Western Slope,
with July's Board memo and other supporting materials attached; comments were solicited in the
letter. As this memo is being written, verbal comments have been received from Eric Kuhn at the
Colorado River Water Conservation District.

Mr. Kuhn was supportive of the use of high-altitude crop coefficients in Colorado and concurred with
the recommendations from Staff. He commented that an increase in calculated crop consumptive use
due to the use of high-altitude coefficients does not necessarily indicate a corresponding reduction in
available future depletions because of the resulting increase in the natural flows calculation. Mr. Kuhn
also wanted to stress that the measure of one's water right is based on historic consumptive use;
therefore, if there is better science that more accurately calculates consumptive use, then it should be
used.

.

Colorado Water Conservation Board
Flood Protection. Water Supply Planning and Finance. Stream and Lake Protection
Water Supply Protection. Conservation and Drought Planning