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Salt River Project
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The Salt River Project or, SRP, is a collective name used to refer to two separate entities: the Salt River Project Agricultural Improvement and Power District, a political subdivision of the state of Arizona, and the Salt River Valley Water Users' Association, a private company that serves as an electrical utility and water provider for the Phoenix metropolitan area. Operating under the umbrella name, SRP, it is one of the primary public utility companies in Arizona.
The name, Rio Salado Project, is used to refer to the improvement projects along the Salt River through the Phoenix Metropolitan Area, is not related to SRP.
HistoryEarly settlers in Phoenix and nearby areas were forced to depend upon the flow of the Salt River to sustain agricultural activities. The river was prone to both floods and droughts and proved to be a less than reliable resource for the settlers. Failed plans to build a dam on the river in 1897 , combined with a series of droughts, heightened the need for controlling the river.
With the passage of the National Reclamation Act of 1902, funding for reclamation projects with low-interest government loans paved the way for the creation of the Salt River Valley Water Users' Association the following year. Over 200,000 acres (800 km²) of private land belonging to the ranchers and farmers in the association were pledged for collateral and the association was officially incorporated February 7, 1903, becoming the first multipurpose project under the reclamation act. Construction on the Roosevelt Dam would commence the following year.
Although the construction of dams was the association’s most visible and costly project, an integral part of the effort was also the construction and improvement of a system of canals designed to distribute the water from the Salt River among the various members living in the valley.
In 1909, a hydroelectric generator was installed at Roosevelt Dam; and, since that day, SRP has also been a major player in the power generation business.
In 1936, the Arizona Legislature allowed for the creation of governmental districts that could finance large-scale agricultural projects with tax-free bonds. Shortly thereafter, the Salt River Project Agricultural Improvement and Power District was created, the second half of SRP as it exists today. Over the next several decades, a series of major improvements along the Salt and Verde Rivers would raise the number of reservoirs in the district to 6, and at the same time SRP was constructing and maintaining a number of other electrical generating stations throughout the state.
As of 2007, SRP owns or operates eleven electrical generating stations, seven hydroelectric plants, and has energy purchasing agreements with four major hydroelectric stations along the Colorado River, making them a major provider of electric service in the Phoenix area. Along with the six reservoirs along the Salt and Verde Rivers, SRP operates dams at the Blue Ridge Reservoir as well as the Granite Reef Diversion Dam and a number of canals, making the SRP a major provider of water to the Phoenix area.
Salt River reservoirsSRP owns and operates four reservoirs along the Salt River east of Phoenix. While the main function of these reservoirs is to serve as water storage for the rapidly growing municipal area, they also serve as important recreational centers. The lakes are regularly stocked with fish, and are supplied with boat ramps for both angling and other watersports.
Theodore Roosevelt Lake
Theodore Roosevelt Dam and the Roosevelt Lake it forms are considered perhaps the crowning achievements of the Salt River Project. With the initial funds raised by the association in 1903, an ambitious project was begun several miles east of Phoenix in the Tonto Valley, at the confluence of the Tonto Creek and the Salt River. When it was completed in 1911, Roosevelt Dam was the tallest masonry dam in the world at 280 feet (85 m). It was dedicated by U.S. President Theodore Roosevelt, for whom the dam and the reservoir are named.
In 1996, a massive expansion project aimed at increasing the capacity of the lake was finished. The dam was resurfaced with concrete and raised an additional 77 feet (23 m), which had the effect of increasing the lake’s capacity by over 20%, and providing much needed flood control space on the Salt River. Shortly after completion, however, the area entered into a prolonged period of drought, and it would be some time before the new capacity was used, with the lake finally reaching historic levels of 90% capacity in early 2005.
With an at-capacity surface area of nearly 21,500 acres (87 km²), Roosevelt is the largest lake that is wholly inside the state of Arizona. It can store 2,910,200 acre feet (3.59 km³) of water at capacity.
Apache Lake
Apache Lake was formed by the construction of the Horse Mesa Dam, finished in 1927. Several miles downstream from Roosevelt, the dam stands 300 feet (90 m) high. The lake itself is considerably smaller than Roosevelt at only 2,600 acres (11 km²) of surface area at full capacity, and can store 254,138 acre feet (313,475,000 m³) of water.
Like the rest of the Salt River lakes downstream from Roosevelt, Apache Lake is long and narrow, filling the bottom of the canyon it resides in. It does have a hydroelectric generating station.
Canyon LakeCanyon Lake, the third lake on the Salt River, is created by the Mormon Flat Dam. The dam was completed in 1925, being the second of the dams to be completed. The dam is named for a nearby geographical feature, a flat campground where Mormon pioneers from Utah would often stop on their journey to the Phoenix area. Downstream from Apache Lake, it is considerably smaller with only 950 acres (3.8 km²) of surface area when full, holding 57,852 acre feet (71,359,000 m³). Like the other Salt River dams, it is equipped with hydroelectric generators.
Saguaro Lake
Saguaro Lake is formed by the Stewart Mountain Dam, downstream from Canyon Lake. Completed in 1930, it was the last of the reservoirs to be built on the Salt River. It is somewhat larger than Canyon but smaller than the others, having a surface area of 1,280 acres (5.18 km²) when full, holding 69,765 acre feet (86,054,000 m³). The dam is equipped with hydroelectric generators.
Verde River reservoirs and other damsAfter completion of the four dams on the Salt River, SRP turned to the smaller Verde River for further expansion of the project. Like the reservoirs on the Salt, the Verde reservoirs are used for recreational purposes as well as water storage and flood control.
Bartlett LakeThe first of the lakes on the Verde River was created with the construction of the Bartlett Dam, finishing in 1939. At 305 feet (93 m) tall, the multiple-arch dam is lacking in hydroelectric generating capabilities, unlike the dams on the Salt River. Bartlett Lake, with 2,700 acres (11 km²) of surface area at capacity, is larger than all the Salt River reservoirs save Roosevelt. When full the lake can hold 178,186 acre-feet (219,789,000 m³) of water, or some 58 billion US gallons.
Horseshoe LakeHorseshoe Lake is formed by Horseshoe Dam and was finished in 1946, upstream from Lake Bartlett. Unlike the other dams built to this point, the construction was done by the Phelps Dodge Corporation as part of a water exchange agreement. In 1949, the city of Phoenix funded the construction of spillway gates for the dam in exchange for water rights for city users. Like Bartlett, this dam does not have hydroelectric generating capabilities. At 2,800 acres (11 km²) in surface area when full it is slightly larger than Bartlett but has a smaller total capacity, holding only 131,427 acre feet (162,113,000 m³) at maximum.
Blue Ridge ReservoirPhelps Dodge, Inc., a large mining company in Arizona, constructed the Blue Ridge Dam in 1965 to help meet its water needs. A water exchange agreement penned three years earlier promised the facilities to SRP, and in 2005 SRP took possession of the dam and water production facilities. Located on the Mogollon Rim, Blue Ridge is not on the Salt or Verde Rivers but is a part of the general watershed covered in the SRP area. The small lake has a storage capacity of only 15,000 acre feet (19,000,000 m³) of water.
Granite Reef DamThe Granite Reef Diversion Dam, constructed near the confluence of the Salt and Verde Rivers, does not actually hold back a reservoir but is used to divert water from those rivers into the system of canals feeding into the Phoenix area. It was actually the first of the dams constructed, finished in 1906 to replace the Arizona Dam, which had been washed away by floods the previous year.
Canal SystemSRP operates several important canals that run in a network through much of the southern half of the Phoenix metro area, helping distribute water from the Salt River system. Major canals operated by SRP are:
- Arizona Canal, 38.62 miles (62.15 km) long
- Grand Canal, 22.43 miles (36.10 km)long
- Consolidated Canal, 18.95 miles (30.50 km) long
- Eastern Canal, 14.73 miles (23.71 km) long
- Western Canal, 13.61 miles (21.90 km) long
- South Canal, 9.91 miles (15.95 km) long
- Tempe Canal, 9.76 miles (15.71 km) long
- New Crosscut Canal, 3.4 miles (5.5 km) long
SRP also operates a number of flood control canals throughout the Phoenix area.
Power generationBesides the power generated at several of the dams along the Salt River, SRP owns or operates, in part, several power generating stations throughout the state:
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