The Colorado River Aqueduct is a 242-mile-long conveyance system which transports water from Lake Havasu to Lake Matthews. The aqueduct is operated by the Metropolitan Water District of Southern California (MWD) as one of the primary sources of drinking water in Southern California. The aqueduct consists of two reservoirs, five pumping plants, 63 miles of canals, 92 miles of tunnels, and 84 miles of buried conduit and siphons. Its capacity is 1.3 million acre-feet per year. Key project elements included aqueduct repairs and instrumentation; switchyards and headgates rehabilitation; protection upgrades replacement of an existing canal liner with a new concrete liner; rehabilitation of sand traps at three pumping plants; rehabilitation of existing siphons including installing internal seals; installing tunnel monitoring instrumentation; and replacement of various circuit breakers.

MARRS successfully completed three task orders under two On-Call Construction Management and Inspection Services contracts.

Task 1: Colorado River Aqueduct (CRA) Construction Management/Inspections County of San Bernardino and Riverside included CRA repairs and instrumentation, switchyards and headgates rehabilitation, fire protection upgrades, replacement of an existing canal liner with a new concrete liner, and rehabilitation of sand traps at three pumping plants. MARRS provided contract administration, office engineering, and inspection services, including 24/7 coverage for three shutdowns of the aqueduct system.

Task 2: Metropolitan, Rialto Pipeline Improvements-Phase I Structures No. 1 & 3 involved the removal of 96-inch diameter welded steel pipe segments, construction of 96-inch replacement pipe, two valve vaults, platforms, four manholes, encasement, and two bypass lines and other appurtenants. MARRS provided hazardous waste remediation oversight and inspection services for removal of pipe coating containing PCB’s, asbestos, and other contaminants. MARRS also provided civil and mechanical inspection services, and mobilized four inspectors to provide 24/7 coverage for a shutdown. The ramp up and ramp down for the shutdown was completed successfully.

Task 3: Colorado River Aqueduct Pump Plants, 230KV Line Reactors and 6-9 KV Switch Houses project involved upgrades to the 6.9 KV switch houses, including the replacement of the vertical bus drops, installation of bus bracing and spacers, demolition of the existing transfer bus, and removal and disposal of the transfer bus oil circuit breakers; installation of 18 Metropolitan-furnished 230kV transient recovery voltage capacitors; construction of reinforced concrete foundations and footings; tie-in with the existing overhead conductors and installation of line tensioning devices; and installation of grounding and construction of perimeter fencing.

Project Features:
• Aqueduct
• Siphons
• Pumping Plants
• Electrical Substation
• Pipelines