Dworshak nutrient supplementation educational meeting Monday, May 23

A public meeting will be held Monday, May 23, co-sponsored by the Walla Walla District Corps of Engineers (COE) and the Idaho Fish and Game Department (IDFG). The meeting will be held at 7 p.m. at the Best Western Lodge at River’s Edge located at

615 Main Street, Orofino.

According to a press release from the COE, issued May 17, nutrients have steadily declined since the construction of Dworshak Dam which was completed in 1972. This has created a “nutrient imbalance” in the reservoir.

In 2007, the District and IDFG partnered to apply prescribed amounts of liquid fertilizer to Dworshak Reservoir to improve the aquatic environment. Prescribed amounts of nutrients were added periodically to the reservoir and closely monitored for detailed scientific analyses. Water sample testing revealed several benefits from the program including: increases in beneficial algae, increased abundance of higher quality food for aquatic life, and healthier, larger fish.

This pilot project was modeled on 30 years of work conducted in Canada on several deep, high mountain reservoirs similar to Dworshak. The project sought to rebalance the nitrogen phosphorous potassium ratio in the water by adding ammonium-nitrate (liquid fertilizer) to the lake in prescribed amounts.

The District informally consulted with U.S. Fish and Wildlife Service, the Nez Perce Tribe, and NOAA National Marine Fisheries Service before starting the pilot project. IDFG and COE have openly communicated about the project in a series of public meetings – the most recent being held on June 29 in Orofino.

The pilot project was paused in July 2010 as the District sought a newly required environmental permit from the U.S. Environmental Protection Agency (EPA). The project team stopped adding nutrients to the reservoir at that time. The EPA is seeking public comments on its proposal to issue a National Pollutant Discharge Elimination System (NPDES) permit. The public meeting is open to any interested persons.