Wonky: Bowman Dam / Crooked River Water Accounting

I’m on the email list that discusses water releases from Bowman Dam into the Crooked River. You can get more details by reading prior posts on the topic (see the Crooked River section), but the executive summary is that the water is supposed to be released for irrigators as well as the “maximum benefit” of fish. How that actually occurs is the subject of constant discussion. The latest email contained the graphic above that really illustrates the operation well.

OID is Ochoco Irrigation District. “Live flow” is water flowing from the upper Crooked River into Prineville Reservoir, “contracted” is water stored in the reservoir under contract to OID. As you can see, a consistent flow of about 150 CFS has been released from Bowman Dam since irrigation season began. The source has changed from live flow to stored (contracted) water as flows into Prineville Reservoir have diminished.

“Other contracted” is North Unit Irrigation District and the City of Prineville (CoP). NUID is having a very tough year meeting water needs and has already used up most of their allocation in the reservoir.

The “uncontracted” water is what the rest of us call the “fish water”. It is not under contract and is to be used for the maximum benefit of fish, although there are arguments that this is not being done. The “pulse flow” was an experiment to see if releasing a large amount of water would help flush reintroduced anadromous smolts out of the Crooked River.

This was a controversial decision. One agency objected to using up a large amount of the fish water in a time of drought. They were overruled and the results are mixed. A large number of smolts were detected at Opal Springs as they moved into Lake Billy Chinook, but the capture rate at the Selective Water Withdrawal (SWW) tower did not see significant improvement.

Below you can see the water accounting as of 6/30/2020.

Remaining (1000 ac-ft)Used (1000 ac-ft)