WSP12636

• 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 II - Appendices-Etc - 08-01-96
• Water Supply Pro - Doc Type: Report/Study

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17 miles northeast of the town of Parker, Arizona. Constructed between 1934 and 1938 by
Reclamation. Parker Dam's primary purpose is to provide reservoir storage from which
water can be pumped into the Colorado River aqueduct and the CAP aqueduct. Lake
Havasu, the reservoir behind Parker Dam, is about 45 miles long and covers 20,390 acres.
It can store 648,000 acre-feet of water. The CAP began pumping water from Lake Havasu
in 1985. It has a capacity for delivery to users in central and southern Arizona.

Parker Dam is one of the deepest dams in the world; 73 percent of its structural height of
320 feet is below the original riverbed. About 85 feet of the dam is visible. The dam's
superstructure rises another 62 feet above the roadway across the top of the dam. Parker
Powerplant is located on the California side of the Colorado River immediately below the
dam. It houses four hydroelectric generating units. Each unit can produce 30,000 kWof
hydroelectric power. Four 22-foot diameter penstocks carry up to 5,500 cfs each, to
feed the generating units. Fifty percent of the plant's power output is reserved for MWD's
use to pump water along the 'Colorado River aqueduct to the Pacific Coast. The remaining
power is marketed by WAPA, a DOE agency. Under an agreement between Reclamation
and MWD, the latter agency financed essentially the entire cost of constructing Parker Dam.
MWD's Whitsett Pumping Plant, 2 miles upstream from the dam on Lake Havasu, lifts water
from the reservoir into the Colorado River Aqueduct.

Davis Dam - The Davis Dam and Powerplant facility was constructed by Reclamation in
Pyramid Canyon, 67 miles downstream from Hoover Dam. The site is 10 miles north of the
point where Arizona, Nevada, and California meet, and approximately 2 miles upstream
from Laughlin, Nevada, and Bullhead City, Arizona.

Completed in 1953, Davis Dam is an earth and rock-fill embankment with a concrete
spillway, gravity structure, intake structure, and powerplant. The dam's primary purpose is
to re-regulate Hoover Dam releases so that they meet downstream demand, including the
annual delivery of 1.5 maf of water to Mexico. This is in accordance with the Mexican
Water Treaty of 1944.

Located on the Arizona side of the river, the Davis Dam Powerplant is immediately
downstream from the dam embankment. Each Davis unit is rated at 50,000 kW. DOE
markets all of Davis energy and capacity. The forebay is formed by the intake, spillway,
and gravity structures.'

Lake Mohave lies behind Davis Dam and is bound for most of its length by the steep walls
of Pyramid, Eldorado, and Black Canyons. The lake is relatively narrow, not more than
4 miles across at its widest point, but provides significant recreation opportunities and habitat
for fish and wildlife. Additionally, the lake captures and delays flash flood discharge from
the side washes below Hoover Dam.

Headgate Rock Dam - Headgate Rock Dam is located on the lower Colorado River about
1 mile northeast of the town of Parker, Arizona, and 14 miles below Parker Dam. It was

Appendix D - 3

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