How Proper Trunk Line Construction Maximizes the Longevity of Reservoir Floating Covers

The Los Angeles Department of Water and Power (LADWP) designed and constructed the Green Verdugo Floating Cover Replacement Project to comply with the Environmental Protection Agency’s (EPA) Long Term 2 Enhanced Surface Water Treatment Rule. LADWP incorporated best practices utilizing data from computational fluid dynamic modeling, installing remotely operated hydraulic actuated valves, and relocating trunk lines to beneath the reservoir floor to maximize the longevity of the floating cover. The construction of the project was subject to two California regulatory agencies. Tie-in connection work was done within the footprint of the dam leading to increased structural requirements. Reinforced concrete encasement and additional steel thickness to the trunk line added to the longevity of the pipe while also providing corrosion protection. The project had a hybrid delivery process through a partnership with LADWP’s in-house construction division and a specialized geosynthetics contractor. All regulatory requirements have been met and Green Verdugo Reservoir is expected to go back into service in February 2024.