fishing

Boise River Temporarily Goes Dry!

Earlier this week, the Boise River had some water issues. Or no water at all, in places. This was due to an equipment failure at Barber dam.

We've had several concerns about effects to fish in the Boise River due to this.

Our biologists are investigating the issue and have written a description of what they look for to make sure the fish stay happy in the beautiful Boise River.

Section of Boise River Goes Dry

Aerial photo of Barber Dam. Courtesy of Thunderhammer3000 at Flickr: https://www.flickr.com/photos/72237776@N00/2840997805

by Joe Kozfkay, Regional Fisheries Manager

On Tuesday evening and Wednesday morning, February 3rd and 4th 2015, a series of unfortunate occurrences at east Boise’s Barber Dam (owned by Ada County and operated by Enel Green Power) caused Boise River flows to drop to zero for a period of seven hours.

Maintenance activities are being performed on the dam’s spillway, and to ensure construction crew safety, Barber Pool is being held at less than full pool levels, with all river flows being routed through one turbine. Unfortunately, the gate that allowed water to reach this turbine closed Tuesday night and alarm systems failed. Upstream flows were then caught in Barber Pool, until the point where the pool was refilled and additional water began cresting the dam’s spillway.

During the seven-hour period of zero cubic feet per second river flow over or through Barber Dam, several miles of the Boise River were de-watered or did not receive the “normal” wintertime minimum flow of 240 cubic feet of water per second. Very few people saw the river in this condition as it occurred in the middle of the night. From a fish habitat standpoint, riffles and run habitats were likely severely de-watered, whereas pool habitat likely retained water. Farther downstream areas were less impacted as infiltration of groundwater re-wetted the river channel.

Winter is a critical period for many aquatic species. Dramatic river flow reductions can have negative impacts on aquatic organisms such as fish and invertebrates. Fish survive the winter by reducing activity levels and seeking habitat where they can avoid expending energy while at the same time avoiding predators. This is especially true for young trout. The Boise River possesses wild, spring-spawning rainbow trout and wild, fall-spawning brown trout. Young rainbow trout reside on the river’ edges, usually near downed wood or other cover. A rapid drop in river level may force young rainbow trout to seek alternative cover and become susceptible to predators. It may also cause stranding and death.

For the most part, brown trout spawn throughout the month of November. Boise River water temperatures result in an approximate 60-day brown trout egg incubation period. In early February, young brown trout are just beginning to hatch or have just recently done so. At this critical life stage, water level drops are known to cause brown trout mortality. Other fish species also reside in riffles and near shore areas and may have been affected by the dramatic drop in river flow, including sculpin, dace, and whitefish.

Idaho Fish and Game crews conducted visual surveys of this river segment on Wednesday afternoon, February 4th. No dead adult fish were observed, which was a positive sign. Measurement of potential impacts to young trout and other species are only beginning and will be much more difficult to determine. Crews are at the river today, sampling riffle and river margin areas in the de-watered area and in downstream reaches to make a relative comparison. This should provide some information on possible impacts of the de-watering event.

Other types of suspected impacts may not be readily measured, especially for young trout, non-game fish, or invertebrate numbers and species. Based on the results of these and subsequent surveys, Fish and Game staff will determine whether appropriate mitigation should be pursued from responsible parties.

Ice fishing Mackay

I've heard good things about ice fishing on Mackay reservoir but don't know anything about it. Is it really safe since only half the water freezes over? What kinds of fish are there in the res? What are the best techniques for catching them?

Tiger Muskies

What is the nearest Idaho lake or reservoir to Pocatello that has Tiger Muskies? Are there bait restrictions or ice fishing restrictions at any of the near by areas with Tiger Muskies?

Steelhead Coming to Boise River

For people living in Idaho's most populous areas, a quest for steelhead means traveling for several hours to the Salmon, Clearwater or Snake Rivers. When times are good, and there is a surplus of steelhead, anglers in Idaho's biggest city have steelhead delivered courtesy of Fish and Game tanker trucks.

On Thursday November 6, Fish and Game trucks will haul around 300 steelhead to Boise from Hells Canyon. These fish are part of a program funded by Idaho Power that compensates for steelhead lost in the Boise River drainage due to the Hells Canyon Hydroelectric Project.

Fisheries managers will release the steelhead into the Boise River at several traditional locations between Glenwood Bridge and Barber Park. Anglers planning to harvest steelhead must have a valid fishing license and steelhead permit. Any steelhead (defined as a rainbow trout longer than 20 inches with a clipped adipose fin) harvested on the Boise River must be recorded on the angler’s steelhead permit. The steelhead limit on the Boise River is three per day and nine in possession. Barbless hooks are not required on the Boise River.