SRP Adds New Dredge to Assist with Water Resiliency

A new, state-of-the-art dredge has been installed at Granite Reef Diversion Dam in northeast Mesa that will collect sand and silt that builds up at the dam every day and assist SRP to efficiently and reliably deliver water to the Valley.

When Granite Reef Diversion Dam was installed in 1908, material would float down from the Salt and Verde reservoirs and build up, eventually spilling into the canals. In response, a dredge was put into service in 1954 to help clean up the area in front of the dam and keep it clear of sediment.  

The new dredge, which was installed using a 500-ton crane, is significantly larger than its predecessor, measuring 70 feet long by 20 feet wide and weighing approximately 130,000 pounds. The new dredge is also faster, completing in just a few hours what took the old dredge an entire week.

"A dredge features a large auger at the front that dips into the water to stir up material," explained Jeff Conyers, SRP Equipment Operator, Pump Maintenance. He has worked at Granite Reef for over 15 years, eight of which as a dredge operator. "An internal pump transfers the water and material through a pontoon line to the shore into a catch basin pit. It's like a giant vacuum cleaner."

Once the basin is full, a sand plant company extracts the material and separates it. That company then sells the sand and silt to businesses like Home Depot and other concrete companies.

The dredge has historically run on weekdays, but for the past two years, the productive winters of 2022 and 2023 brought in a lot of silt and sand into the reservoir system. This has required the dredge to operate seven days a week.

The new dredge boasts upgraded computer screens and joysticks, replacing the old handles and clutches. While the old dredge needed extra time to warm up, the new one is ready in minutes and is three to four times more efficient. It also has GPS and a mapping system to show where dredging is still needed. 

Reporters are invited to see the dredge up close and working on removing tons of silt at Granite Reef Diversion Dam. Contact: Patty Garcia-Likens, (602) 245-0047.