Delivering Pathogen-Free Water to Salmon Hatchery

Two dams in Olympic Nationa Park, Glines Canyon and Elwha, were slated for removal beginning in 2011 as part of the National Park Service’s Elwha River Restoration project. Both dams were upstream of a salmon hatchery owned and operated by the Lower Elwha Klallam tribe. To prepare for this project, the tribe needed to move the hatchery to protect it from increased risk of flooding and river-channel migration after the dams were removed.

GeoEngineers provided hydrogeologic services to develop a reliable groundwater supply for a new $16 million tribal hatchery, which was completed in May 2011. Our team designed, drilled and tested several wells that the hatchery now relies on almost exclusively for a supply of sediment-free water, vital to healthy fish development.

Approach

A fresh supply of pathogen-free water to the hatchery, meaning it’s clear of harmful bacteria and other materials, is vital for incubating and hatching new fish. While drilling the ground wells that would supply this water, the project team encountered a complex mixture of silt, sand, gravel and cobbles deposited by the Elwha River due to the dam removal project. To counteract this, GeoEngineers designed well screens to filter the sediment out of the water supply and performed draw down tests to establish sustainable pumping rates.

Results

The hatchery was opened with much fanfare in May 2011.  The project was successful in developing a groundwater supply that became essential to the hatchery’s operations after the dam removal project interrupted the existing surface water supply. GeoEngineers has continued our hydrogeologic consultation, helping the tribe evaluate groundwater impacts associated with the dam removals, monitor well performance, improve well efficiency and optimize well field operations.