09:51 AM

SRP to Conduct Spill Gate Test on Roosevelt Dam

Media Advisory:


Salt River Project will conduct a spill gate test of Roosevelt Dam on Wednesday, May 10, which happens annually to confirm operational readiness in the event of flooding. This year’s test is unique and will be performed to also support SRP in releasing water from the dam’s flood control space, as required by the Army Corps of Engineers. The test will run longer in duration to assist in this required release.

After a very wet and productive winter, Roosevelt Dam is at the highest level it has ever been. This is the third time since 1996 that there is water in the dedicated flood control space which is designed to slow down large flood events. This year’s test is expected to release about 2,000 acre-feet of water or 650 million gallons downstream in Apache Lake.

In addition to the spill gate test, SRP performs other periodic inspections to ensure the safety and functionality of dam systems and equipment, including electric generating capabilities.


Roosevelt Dam Annual Spill Gate Test 


Wednesday, May 10
Spill gate tests to happen from 9 a.m. to approximately 10:30 a.m. 
*Media to arrive between 8 a.m. and 8:30a.m. and wear close-toed shoes. 
Contact Erica Roelfs by May 8 at erica.roelfs@srpnet.com if planning to attend. 

Roosevelt Dam Overlook Link to observation area location


Reporters will be directed to the Roosevelt Dam Overlook where they can capture video and photos of the test. SRP Hydro Generation O&M Supervisor Buck Phelps will be available for interviews at this location. 

  • 9 a.m. – The spill gate test begins with both sides of the dam releasing a total of about 4,000 cubic feet per second for 10 minutes. During the initial 10-minute test, about 80 acre-feet of water or about 26 million gallons of water will be released. 
  • 9:10 a.m. – The left spill gate will close and the right spill gate will remain open for approximately one hour releasing an additional 240 acre-feet of water or approximately 78 million gallons. (In total, 104 million gallons will be released during the tests.) 
  • All water released from Roosevelt Dam during the test will remain stored downstream in the Salt River reservoir system in Apache Lake, south of Roosevelt Lake. 
  • Safety is our greatest concern and site personnel performed several operational checks as well as a pre-spill safety tailboard. A representative from the Bureau of Reclamation, Phoenix Office, will be present to witness the test. 


Snowpack on the 13,000-square-mile watershed is the deepest it has 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.

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.