Lake Mathews Emergency Gate Repair

This summer, Metropolitan Water District of Southern California (MWD) called on Power Engineering Construction for help with complex, emergency underwater repairs to fix a stuck gate at Lake Mathews in Riverside, CA, a critical source of drinking water for their customers across Southern California.

MWD discovered that the roller gate for Outlet Tower #1 at the Junction Shaft was stuck in the open position. This compromised MWD’s ability to prevent poor-quality water from entering the system. To protect their customers, MWD moved quickly to isolate Tower #1 by closing all 18 blind flanges inside the structure and free the malfunctioning roller gate.

Because of depths of up to 127 feet and confined space conditions, it was not recommended for MWD divers to perform this work. MWD turned to our team. With ADCI-certified crews and specialized decompression dive spreads capable of supporting work at these depths, Power Engineering Construction was the safest, most cost-effective, and expeditious option to get the work done.

Normally, a project like this would take 2 to 3 months of planning. Here, we had only three weeks. Summer is also peak season for diving work, so assembling two full six-man dive teams on such short notice was a challenge, but one we delivered on. Over the course of a five-day outage, the crews sealed 18 blind flanges in Tower #1, freed the roller gate, and were able to clean and cycle Gate #2 in the process.

This fast-track effort showed the power of collaboration between MWD engineers, inspectors, mechanics, and our dive teams. It was a focused response that kept Lake Mathews operating reliably for MWD’s customers.

‍