BOARD00069

• Board Meeting Date: 5/24/1999
• Description: ISF Section - Colorado River Basin Issues - San Juan/Chama Project - ISF By-Pass Issues
• Board Meetings - Doc Type: Memo

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Colorado Water Conservation Board

Department of Natural Resources
1313 Sherman Street
Denver, Colorado 80203
Phone: [phone]
FAX: [phone]

STATE OF COLORADO

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Bill Owens
Governor

Greg E. Walcher
Executive Director, DNR

Peter H. Evans
Director, ewes

MEMORANDUM

To: Colorado Water Conservation Board Members

From: Dan Merriman
Todd Doherty

Date: May 17, 1999

Re: Agenda Item 9c, May 24-25,1999, Board Meeting--
Instream Flow Program - Colorado River Basin Issues
San Juan / Chama Project -lnstream Flow By-pass Issues

Proiect Background
The Rio Blanco is a tributary of the San Juan River and is a significant source of water for
Bureau of Reclamation's San Juan-Chama Project. This project, part of the Colorado River
Storage Project, is a major trans-basin diversion that provides an average annual diversion of
about 110,000 acre-feet of water from the upper tributaries of the San Juan River for use in the
Rio Grande Basin, New Mexico. During the 1996-1997 water year, the project diverted
approximately 70% of the river's historic flows. These reductions in flow have contributed to
poor water quality conditions, reduction in fishery habitats, streambank erosion, sediment
loading, relatively high water temperatures and a wide, shallow streambed with little pool habitat
and cover to support a cool water fishery. A Bureau of Reclamation report describing the San-
Juan Chama Project's facilities and operations is attached for more information.

CWCB's Instream Flow Rights versus the Bureau's Bv-Pass Requirements
The CWCB holds an instream flow water right on the Rio Blanco from the San Juan-Chama
Diversion dam to the confluence with the San Juan River with an appropriation date of
December 4,1974. As shown in the table below, the CWCB's instream flow water right and the
Bureau's by-pass requirements differ.