BOISE – (Aug. 15, 2019) – The Idaho Department of Water Resources issued a Notice of Violation to Ada
County on Wednesday for improper operation of Barber Dam, which cut off the entire flow of the Boise
River in the early morning hours of Aug. 2, depriving downstream irrigators of their water, as well as
disrupting fish, recreation and maintenance flows on the river.
The NOV seeks a monetary penalty of $50,000 from Ada County. It also asks Ada County to fix a
recurring problem when power outages occur at the hydropower facility.
“I’m sure it’s obvious to all of the Boise River water users and the canal companies responsible for
delivering water to farmers that recurring episodes at Barber Dam that cut off flow to the river and
harm downstream users are unacceptable,” said Gary Spackman, Director of IDWR.
Ada County owns and operates Barber Dam and a hydropower facility incorporated into the dam.
During the early morning hours of Aug. 2, 2019, multiple downstream canal operators notified the Boise
River Watermaster of reduced water flows at their canal diversions, officials said. A power failure
occurred at the Barber Dam beginning at roughly 1 a.m. on that day. The power outage lasted more
than an hour and resulted in the interruption of the Boise River flow downstream. Upon restoration of
power at the dam, Boise River flows spiked for a short time, causing potentially dangerous conditions in
the river, officials said.
When there is a power outage at Barber Dam, the penstock supplying water to the turbines closes, and
flows in the Boise River below Barber Dam are reduced to zero, officials said. The river flows are
subsequently impounded on the upstream side of the dam until water begins pouring over the crest of
the dam. The impounded water level rises until the water flowing over the dam crest equals the
upstream flow into the impoundment, officials said.
During the time between power plant shutdown (no flow) and equalizing flow over the crest of the dam,
automatic gates at the diverting works for the Ridenbaugh Canal, located just below Barber Dam,
completely open. The Ridenbaugh Canal will divert all water divertible at the head gate. Flows diverted
into other canals downstream are reduced, disrupting irrigation water use sometimes for hours.