Nearly 500,000 trout will be destroyed in a Great Falls-area fish hatchery after a Missouri River dam temporarily lost electricity, causing water to rise and possibly contaminate the facility.
Around 4 a.m. on May 12, the generating unit at Rainbow Dam tripped offline. The temporary loss of power at the dam interrupted NorthWestern Energys ability to control and monitor the reservoirs water elevation. During a period of about 35 minutes, water levels in the reservoir rose about 18 inches.
Staff arriving the next morning at Giant Springs Fish Hatchery, located upstream and adjacent to the dam, discovered the water reached about an inch above boards separating the facilitys outside raceway from the river. The inside raceways and tanks at the hatchery were not infected by river water.
The breech means spring-sourced hatchery water may have mixed with untreated river water, Montana Fish, Wildlife and Parks said in a news release, bringing with it unknown pathogens. FWP uses spring water at all hatcheries to avoid disease.
http://helenair.com/news/natural-resources/updated-fwp-to-destroy-nearly-k-hatchery-trout-following-dam/article_d3730645-92c3-5cdf-b4a8-5a0dc8b046ca.html