Tempe Town Lake along Salt River being emptied for new dam

Tempe Town Lake, a 16-year-old manmade creation that transformed a 2-mile stretch of the normally dry Salt River bed into a place for public recreation and relaxation along with spurring economic development around downtown Tempe, is slowly being emptied so its current dam can be replaced with a new one.

Tempe began pumping 800 million gallons of water from the lake into an irrigation-water canal system. Emptying the lake will take up to three weeks.

Once the lake is empty, workers will remove the old dam that uses giant rubber bladders to hold back the lake’s water.

Construction of a new steel-and-concrete dam is nearly complete, and the lake should be refilled by April 30 if the weather cooperates.

City spokeswoman Kris Baxter-Ging says the lake is popular with residents and visitors alike for its peaceful environment. She says the flood control provided by the lake allows the development of areas along the river channel.

Emptying the lake has halted water activity such as fishing and boating until April 30. However, lakeside paths and parks used for skating, running, bicycling and walking remain open.

Boaters who row, paddle and sail on the lake will temporarily have to find new venues, and an annual dragon boat festival was rescheduled to October from March.

An annual October event celebrating the stocking of the lake with rainbow trout for fishing over the winter months was canceled to help reduce the fish population before emptying the lake.

Arizona Game and Fish Department spokesman Nick Walter says the lake’s size and location makes it a valuable resource for urban anglers. He says the department hopes to restock the lake as soon as possible.

Arizona State University architecture students initially conceived the lake in the 1960s – decades before it was built and opened in 1999.

The lake emptied in 2010 when one of the rubber bladders burst.

Tempe then leased replacement bladders while it studied options for a permanent new dam, resulting in the one now on the verge of completion.

The dam-replacement project cost is $47 million, including removal of the old dam.

The lake covers about 220 acres and has an average depth of 12.5 feet.

Water now in the lake is being pumped into the Salt River Project canal system. The SRP delivers water to farmers, city parks and homeowners in parts of the Phoenix area for irrigation.

The new dam’s eight gates will be hydraulically operated, allowing them to be opened to allow surges of flood water to pass downstream and then raised to capture the tail end of the flow to refill the lake.

City officials say the amount of water lost from the lake annually to evaporation is about the same amount used on two golf courses or a 1,000-acre alfalfa field.