WSP12637

• File Number: 8282.300
• Description: Colorado River Operations and Accounting - Lower Basin Administrative Procedures
• State: CO
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 8/1/1996
• Author: DOI-BOR
• Title: Description and Assessment of Operations-Maintenance and Sensitive Species of the Lower Colorado River - Volume I - Report - 08-01-96
• Water Supply Pro - Doc Type: Report/Study

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Oil2325

pump-storage facility is to improve water delivery reliability and to reduce waste of
Colorado River water when water orders change or precipitation causes side-channel inflow.
The facility allows Reclamation to capture and store water not needed for delivery below
Parker Dam or to release water if demands are greater than the existing river supply.

Imperial Dam is located 90 miles downstream of Palo Verde Diversion Dam or 147 miles
downstream of Parker Dam (the last storage or regulation facility). Imperial Dam was built
between 1936 to 1940 as a gravity diversion facility for the All-American Canal, to replace
the original Alamo Canal, and as a diversion facility for the Gila Gravity Main Canal.
Imperial Dam has no effective storage or flood control capability and stores water to a
maximum depth of 23 feet. Water is released though the dam though the sluiceway gates.
The All-American Canal can transport a maximum water flow of 15,155 cfs and supplies
water to the Imperial Irrigation District (lID), the Coachella Valley Water District (CVWD),
and other small users. The Gila Gravity Main Canal can transport up to 2,200 cfs and
supplies water to the Wellton-Mohawk Irrigation and Drainage District (WMIDD) and to the
Yuma area. Water also is diverted and pumped between Palo Verde Diversion Dam and
Imperial Dam for domestic, irrigation, and environmental uses. Typical water travel time
from Palo Verde Diversion Dam to Imperial Dam is about 2 days.

Laguna Dam is located 5 miles downstream of Imperial Dam and was constructed between
1905 and 1909 as part of the Yuma Project to provide for gravity diversion of
Colorado River water. However, with the construction of Imperial Dam immediately
upstream, the Yuma Project was reconfigured in June 1948 to use Imperial Dam for the Gila
Gravity Canal diversion. The dam creates Mittry Lake and impounds water to a depth of
10 feet at a surface elevation of 154 feet. Today Laguna Dam serves as a regulating
structure for sluicing flows controlling downstream sediment and helps meet Mexico's water
delivery orders. Typical water travel time from Imperial Dam to Laguna Dam is about 2
hours.

Morelos Dam is located 22 miles downstream of Laguna Dam and is the primary
Colorado River water diversion facility for Mexico. The water is transported into the
Alamo Canal for use in Mexico. The dam has no effective storage or flood control capacity.
Morelos Dam was built, and is operated and maintained, by Mexico. Typical water travel
time from Laguna Dam to Morelos Dam is about 6 hours.

The Limitrophe Division is the 22-mile reach of the river that borders Mexico and extends
from Morelos Dam to the SIB near San Luis, Arizona. The division is essentially dry during
normal years due to the diversion of water by Mexico at Morelos Dam.

B. The Secretary's Discretionary Management Activities

This section presents a condensed description of those activities of the Secretary, acting
either directly or through Reclamation, undertaken in the operation and maintenance of the
lower Colorado River and its reservoirs. This information is provided to establish an
understanding of those activities and to provide a basis for an informed biological opinion

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