Another fish kill coming to the Crooked?

Crooked in winter

As Central Oregon anglers know, fish populations in the Crooked River can wildly fluctuate.  When there is adequate flow for a few years the fishing can be excellent.  On the other hand, a variety of factors including low flows combined with freezing temperatures can create massive fish kills.  The last of these events happened in the winter of 2015-2016 when trout populations dropped from 1,383/km to 185/km, the lowest ever recorded.  Based on current water management plans, such a kill could happen again this winter.

Oregon Department of Fish & Wildlife studies of the Crooked River below Bowman Dam have determined that releases of 90 cubic feet per second (cfs) in the winter is “necessary to provide sufficient habitat to support robust and viable salmonid populations” (trout and mountain whitefish).  ODFW does not control water releases, however.  That is done jointly by the Bureau of Reclamation who represent the interests of irrigators along with the US Fish and Wildlife Service and the National Marine Fisheries Service who are supposed to represent fish and wildlife.

Per federal legislation, any water not specifically contracted for irrigation, about half of Prineville Reservoir, is to be released for the maximum biological benefit of fish.  In the past BOR, USFWS, and NMFS have set a target for winter releases of 80 cfs which does not meet the maximum biological benefit standard but is somewhat close.  This winter they are planning to release only 50 cfs, or just over half of sufficient habitat flows.  This in spite of the fact that Prineville Reservoir is still 36% full.  There is enough fish water to meet flows of 80 cfs this winter.

50 cfs, on the other hand, will clearly stress fish with less usable habitat, increasing  competition for food and exposure to predators.  Growth rates will certainly slow.  Populations will decrease but perhaps not dramatically if mild temperatures prevail.  A dry, cold winter, however, could lead to the sort of catastrophic die-off that happened the winter of 2015-2016 when the river was lowered initially to 50 cfs, then to 35 cfs, and subsequently froze over.  The fish in the Crooked are still recovering from that winter.

The low flow decision has been made due to fears that Central Oregon will continue to experience drought for at least another year leading to insufficient precipitation and snow pack to fill Prineville Reservoir (or now empty Wickiup Reservoir).  Current weather projections indicate this is likely and some level of caution does appear to be prudent.

The problem, however, is that whatever water is in Prineville Reservoir will be reallocated to the irrigation districts when irrigation season begins next April.  Irrigators get priority access to water, known as “first fill”, so saving fish water this winter is likely to benefit irrigators, not fish. There are some scenarios where saving fish water could benefit fish next summer but other scenarios give current fish water to irrigators. It all depends on what happens this winter.

Years ago, federal legislation directed irrigators to work with agencies and environmental groups to come up with a drought management plan.  Unfortunately, no meaningful progress has been made on that. The long delayed Habitat Conservation Plan could also play an important role in maintaining viable flows for fish and wildlife. Unfortunately, the HCP is now 10 years overdue. The irrigators continue to do whatever they can to protect their access to water and fish and wildlife continue to suffer.

As I have written previously, hope is not a plan, but right now hope for a wet, mild winter is all the irrigators, BOR, USFWS, and NMFS have to offer.