Annual Operating Plan for Colorado River Reservoirs 1998

• Description: Annual Operating Plan for Colorado River Reservoirs 1998
• State: CO
• Date: 9/3/1997
• Title: Annual Operating Plan for Colorado River Reservoirs 1998
• Water Supply Pro - Doc Type: Operating Principles/Plan

consideration of the uses and purposes identified in the 1970 Operating Criteria and the 1992
Grand Canyon Protection Act, including ecological impacts to the Grand Canyon.
Table 3. Glen Canyon Dam interim flow restrictions
Parameter
(cros)
(cfs)
conditions
Maximum flow
708.0
25,000
Minimum flow
141.6
5,000
nighttime
226.6
8,000
7:00 am to
7:00 pm
Ramp rates
ascending
113.3
4,000
per hour
descending
42.5
1,500
per hour
Daily fluctuations (2)
141.6 / 226.6
5,000 / 8,000
Lake Mead
For calendar year 1997 the surplus condition was the criterion governing the operation of Lake
Mead in accordance with Article III(3)(b) of the Operating Criteria and Article II(B)(2) of the
decree in Arizona v. California. On February 28, 1997, Reclamation informed the International
Boundary and Water Commission (IBWC) that there existed for calendar year 1997 surplus
waters of the Colorado River within the provisions of Article 10(b) of the 1944 Mexican Water
Treaty. On March 27, 1997, the IBWC sent Reclamation a revised delivery schedule for Mexico
with total deliveries of 2,096 MCM (1.7 MAF).
Based on the January 8, 1997 inflow forecast, flood control releases from Hoover Dam were
initiated on January 17, 1997 at the 19,000 cfs level, as required by the Flood Control
Regulations developed by the Army Corp of Engineers and the Bureau of Reclamation. These
releases were continued through February, 1997. The March, 1997 flood control releases were
below the 19,000 cfs level. Releases of 713 MCM (578 MAF) were released above downstream
requirements in January, February, and March, 1997.
(1) to be evaluated and potentially increased as necessary and in years when delivery to the
Lower Basin exceeds 10,152 MCM (8.23 MAF)
r2> Daily fluctuations limit is 141.6 cros (5,000 cfs) for months with release volumes less
than 740 MCM (.600 MAF); 169.9 cros (6,000 cfs) for monthly release volumes of 740
to 987 MCM (.600 to .800 MAF); and 226.6 cros (8,000 cfs) for monthly volumes over
990 MCM (.800 MAF)
September 3, 1997 12