10:43 AM

SRP Conducts Spill Gate Test on Roosevelt Dam

This year’s test ran long in duration to release water in the flood control space

Click for downloadable drone footage and Broll  from this year's spill gate test.

Salt River Project conducted a successful spill gate test of the Roosevelt Dam on Wednesday which was extended in duration. This is an annual test to confirm operational readiness in the event of flooding, and provides valuable information on the dam’s ability to handle inflows from flood events.  

After a wet and productive winter, Roosevelt Lake was at the highest level it has ever been, with water in its dedicated Flood Control Space which is designed to slow down large floods. This was the third time this has happened since 1996. The spill gate test ran longer than previous years to evacuate all the water from the Flood Control Space, as required by the Army Corps of Engineers. 

During the test, all four of the spill gates were open for the first 50 minutes and then the two spill gates on the right side closed – referring to the right side if looking upstream at the dam. The other two gates remained open for about two and a half hours, and in total, the test released about 2,000 acre-feet of water or about 650 million gallons of water downstream in Apache Lake. This is compared to a typical release which consists of both gates being open for about 10 minutes and a release of about 5 acre-feet of water. 

"This functional test, which is performed annually, is a sure-fire way to ensure the readiness of our water release capability," said Ivan Insua, SRP’s Director of Hydro Generation. "We will also be leveraging this season’s generous runoff by releasing some water in our Flood Control Space, which is above and beyond our normal conservation elevation, to perform an extended spill gate operation. This gives us very useful information on the gate and spillway performance."

This past winter, snowpack on the 13,000-square-mile watershed that replenishes SRP’s reservoirs was the deepest it’s been in 30 years. More than 700,000 acre-feet of water or about 228 billion gallons have been released into the normally dry Salt River since March to ensure the reservoirs can handle all inflows from this winter’s snowmelt.

Currently, the SRP reservoir system is at full capacity.

"Our dams and reservoirs are doing exactly their intent: to store as much water as possible in times of wet and serve our communities for times of dry," Insua said.

See here drone footage captured from this year's spill gate test.

About SRP

SRP is a community-based, not-for-profit public power utility and the largest electricity provider in the greater Phoenix metropolitan area, serving approximately 1.1 million customers. SRP provides water to about half of the Valley’s residents, delivering more than 244 billion gallons of water (750,000 acre-feet) each year, and manages a 13,000-square-mile watershed that includes an extensive system of reservoirs, wells, canals and irrigation laterals.