As Bulletin readers know, we are in a drought. As of May 20, most of Central Oregon is experiencing “extreme” or “exceptional drought,” our snowpack is at 81% of average, and groundwater is far below normal. Consequently, rivers and reservoirs are also low.
While diminished water availability will create hardship for some, though not all, local irrigation districts, let’s not forget that the drought will create lethal conditions for fish in many local waterways. Here’s a look at one example, the Crooked River.
Prineville Reservoir is at 56% of capacity, far below average for this time of year with little snowpack remaining in the Ochocos for spring runoff. During irrigation season, water will be released from the reservoir to meet irrigation demands from Ochoco Irrigation District and a much smaller amount for North Unit Irrigation District. Essentially all of it will be withdrawn by the time it passes through the city of Prineville, the location of the last major OID diversion. NUID has a diversion below that, just above Smith Rock State Park. When they call their water from the reservoir, there will be temporary spikes in flows below Prineville, but that water will be diverted as well.
The Bureau of Reclamation maintains a web site (www.usbr.gov/pn/hydromet/destea.html) where you can see flows in the upper Deschutes River Basin. On Friday, May 21, flows out of Prineville Reservoir (seen in the PRVO gauge) were 180 cubic feet per second after being at 230 cfs the prior week. Flows below Prineville (CAPO gauge) were at a lethal level of 9 cfs after being just above 60 cfs. The changes in flow are from NUID calls on their water.
Most Central Oregonians are familiar with the federally designated Wild and Scenic River section of the Crooked immediately below Bowman Dam, which will have adequate flows, but the entire river is important for fish. Nine cfs is not healthy aquatic habitat. It will not adequately support redband trout, juvenile steelhead, or currently returning adult spring chinook salmon. As of Thursday, May 20, three adult spring chinook have gone up the Opal Springs fish ladder near the mouth of the Crooked River. They will not make it far, however, due to low flows making the river impassable upstream.
Sudden, dramatic swings in flows from NUID calls are also detrimental, potentially stranding fish and stirring up sediment.
It is also important to know that the Crooked River below Prineville is highly polluted from agricultural runoff. This has been well documented by the Crooked River Watershed Council and a study by Portland General Electric, which was looking into sources of pollution in Lake Billy Chinook. Low flows concentrate those pollutants in the river.
The Deschutes Basin Habitat Conservation Plan does have provisions for drought years and preserving flows below Prineville, but only during nonirrigation season (winter). In those months, a minimum of 50 cfs is required from Bowman Dam all the way to Lake Billy Chinook. Paradoxically, this is not a year -round requirement.
Even with the drought, water in Central Oregon remains adequate to meet the needs of people, farms and fish but is allocated based on decisions made over 100 years ago. Eighty-six percent of our water supply is used by patrons of irrigation districts, frequently by landowners who do not use it for economically productive agriculture. It’s past time to reexamine how water is allocated in Central Oregon.