Project Summary

On January 18, 2023, the City of Lewiston's 100-year-old potable water reservoir ruptured. The escaping water caused considerable damage to the earthen berm, sloped concrete liner, and cover structure. The City reached out to IMCO and Stantec to design and perform repairs and improvements under an emergency design-build contract. It was critical that the team restore service by July of the same year in order to salvage the city’s irrigation season and complete the startup of the Lewiston Water Treatment Plant for the 11,200 citizens that the reservoir serves. This fast-tracked contract included demolition of the roof structure over the existing reservoir and the installation of a new 40-millimeter polypropylene liner and floating cover.  



Lewiston, Idaho


City of Lewiston

Contract Amount

$2.7 milllion


January 2023 - September 2023

Anticipated Completion

September 2023

Project Highlights

The design and construction of the Lewiston High Reservoir Repairs were completed in under five months. This project was a great success because of the partnership between IMCO, Stantec, the IDEQ permitting staff, and the City of Lewiston.