BOARD01959

• Board Meeting Date: 5/11/1998
• Description: WSP Section - Colorado River Basin Issues - Aspinall Operations - 1998 Planned Spring Peak
• Board Meetings - Doc Type: Memo

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STATE OF COLORADO

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Colorado Water Conservation Board
Department of Natural Resources
721 Centennial Building
131 3 Sherman Street
Denver, Colorado B0203
Phone: [phone]
FAX: [phone]

MEMORANDUM

TO:

Colorado Water Conservation Board Members

FROM:

Randy Seaholm ~
Chief, Interstate Streams Investigation Section

DATE: May 5,1998

SUBJECT: Agenda Item 26i, May 11-12, 1998 Board Meeting-
Colorado River Basin Issues,
Aspinall Operations -1998 Planned Spring Peak

Introduction

Aspinall operation meetings are held during January, April and August of each
year to gather input used to help determine upcoming operations for Blue Mesa, Morrow
Point and Crystal Reservoirs. This information is also used in the development of the 24-
month study for operation of major Reclamation projects in the Upper Colorado River
Basin (Glen Canyon, Navajo, Fontennelle, Flaming Gorge, Aspinall and Taylor Park).
The operations at Aspinall are based on projected inflows to the reservoirs,
existing water rights, minimum instream flows, reservoir target elevations, flows for
endangered fish and other resources, recreation, hydropower, and other factors. The
meetings allow water users and other interested parties to understand projected operations
of the Aspinall Unit for the coming months, exchange information and to coordinate their
activities.

Discussion

On April 14, 1998, the snowpack above Blue Mesa was 106 percent of normal and
the most probable April-July inflow was projected to be 600,000 acre-feet (86% of
normal). Under these conditions, Blue Mesa is expected to fill or nearly fill in late June
or early July. Given these conditions, Reclamation has made a considered decision this
year to provide a "planned peak" in the Black Canyon flows during May. This peak will
result in approximately 3,000 cfs through the Black Canyon. The peak would be
generated by a scheduled bypass of water out of Crystal Dam, rather than allowing the
random bypass of the Crystal Powerplant that often occurs during runoff because
tributary inflows when added to releases from Blue Mesa and Morrow Point often exceed
the 2,030 cfs power penstock capacity of the Crystal hydropower plant. In this respect,
we are just "reshaping" the bypasses that would likely occur during runoff anyway. No
water is currently projected to bypass either Blue Mesa or Morrow Point except for

Roy Romer
Governor

James S. Lochhead
Executive Diret.lor, DNR
DariesC. Lile,P.E.
Director, eWeB
PeterH. Ewms
Acting Director, eweB