Idaho creeks again home to chinook

LEWISTON, Idaho — Juvenile spring chinook are swimming in Sweetwater and Lapwai creeks on the Nez Perce Reservation for the first time in nearly a century.

Soon the young fish, released by the Nez Perce Tribe on March 9, will begin their migration to the Pacific Ocean and within two years some of them can be expected to return as adults and provide fishing opportunities, broodstock for future hatchery production and natural spawning as well.

The roughly 200,000 smolts were produced at Dworshak National Fish Hatchery and raised at the Nez Perce Tribal Hatchery under the Lower Snake River Mitigation program that was established to replace salmon killed by the four federal dams between Lewiston and the Tri-Cities. The release was made possible by years of cooperative work between the tribe, the Lewiston Orchards Irrigation District and the U.S. Bureau of Reclamation that has turned Sweetwater Creek in particular into a more hospitable environment for fish.

Since its inception in the early 1900s, the irrigation district has tapped the headwaters of Webb, Sweetwater and other creeks on Craig Mountain south of Lewiston and delivered water used to irrigate pastures, orchards and now mostly lawns in the Lewiston Orchards.

But it also meant the creeks, home to Endangered Species Act-protected fish like steelhead, ran low and hot in the summer months.

In 2010, the tribe sued multiple federal agencies seeking to return water to the creeks. Negotiations between the parties and other stakeholders yielded a settlement centered on drilling a series of deep aquifer wells in the Orchards. Each time a new well comes online, an amount of water equal to its output stays in the creeks.

David Johnson, director of the tribe’s Department of Fisheries Resources Management, said the exchange increased flows in Sweetwater Creek from a range of zero to 3.5 cubic feet per second in summer months to a range of 3.5 cfs to 12.5 cfs. The tribe has also worked to improve habitat through various rehabilitation projects such as reconnecting the creek to its floodplain and planting vegetation along its banks.