Lower Colorado Region

Phoenix Area Office - Facilities
New Waddell Dam

Construction of New Waddell Dam began in 1985, and continued through 1994. New Waddell Dam's primary purpose is to store Colorado River water for CAP use. The dam also stores Agua Fria River runoff and provides flood protection by controlling river flows. The dam is located one-half mile downstream of historic Waddell Dam, which was built by the Maricopa Water District (MWD). The dam's reservoir, Lake Pleasant, also stores water for MWD irrigation.

In the winter, Colorado River water is pumped uphill from the CAP aqueduct into Lake Pleasant when power rates are low. In the summer, when demand for water and electricity increases, water is released through the Pump-Generating plant, producing hydroelectric power that is sold to help repay the CAP's construction costs. In addition, New Waddell Dam adds 7,000 surface acres to the lake, greatly increasing the recreational value of Lake Pleasant Regional Park.

Handicapped-accessible recreational facilities include 3 multiple-lane boat ramps, 450 picnic sites, 225 campsites, 14 group use areas, 4 overlooks, a full-service marina equipped to handle 1000 boats, and 7 miles of trail. Because the reservoir water level may fluctuate up to 125 feet during a typical year's operation, the facilities will be located to be accessible during both high and low water periods.

If necessary, floodwaters can be released from the dam through the river outlet works tunnel into the Agua Fria River immediately below the dam. If the reservoir's flood storage capacity is ever exceeded, water can also be released over spillways located west of the dam. This water would flow down Morgan City Wash and back to the Agua Fria River about one mile below the dam.

The cost of constructing New Waddell Dam was more than $625 million. The Central Arizona Water Conservation District, which operates and maintains the CAP, is repaying $175 million of this cost.

Reclamation constructed several wildlife water catchments on the sides of the reservoir to reduce animal/vehicle collisions and funded a study to determine the effect of reservoir operation on the fish and the bald eagles that use the lake. The area around a bald eagle nesting site on the upper reservoir is closed to boaters, vehicles, and hikers during breeding seasons when the eagles occupy the nests. A barrier was erected on a tributary in the upper lake to protect a population of endangered Gila topminnows from non-native fish that might move upstream from the reservoir during high water periods

HISTORIC WADDELL and BEARDSLEY DAMS

Formerly named Pleasant Dam, historic Waddell Dam was built in 1927 and was the Valley's only local water facility successfully constructed by private interests. Upon its completion, this project became the largest multiple arch dam in the world.

Waddell Dam was partially dismantled and breached before it was covered with waters from enlarged Lake Pleasant. A 224-foot wide breach opening in the dam was cut in two sections using a diesel-powered diamond wire saw. The formal breaching of the dam occurred on December 4 and December 16, 1992 when the saw-cut sections were toppled into Lake Pleasant. The breaching provides a channel between the two dams to allow water levels to remain the same in front and in back of the old dam and provide safe passage on the lake.

The Camp Dyer Diversion Dam, once known as Beardsley Dam, is located 1.25 miles downstream from Waddell Dam. Constructed in 1895, the dam was part of initial efforts to bring water resources to the Valley. The dam was constructed of quarried rock which was set in place using a cable conveyor that spanned the length of the dam. To accomplish the job, 36,000 cubic feet of earth was excavated and 18,000 cubic yards of masonry was set, all within a single year.

In order to ensure the delivery of a constant volume of water from New Waddell Dam, the diversion dam was rebuilt and raised four feet. The masonry dam and concrete dike were overlaid using Roller Compacted Concrete methods. This dam diverts lake water into the canals which transport the resource to Valley users. This project was completed in August 1992.