The Bend Bulletin has recently had a couple of good articles on the end of irrigation season which I wanted to comment on. “Deschutes River users brace for annual ramp down of water” discusses how Central Oregon Irrigation District has turned off their water deliveries as they prepare for additional main canal piping. “Water flows to some farmers cut off from irrigation due to drought” discusses how water is being turned on for the next 2 weeks to both North Unit Irrigation District and Arnold Irrigation District. While these are well written articles, and I appreciate the Bulletin’s continued coverage of local irrigation water issues, I believe some clarification and discussion is warranted.
As you know, local irrigation districts control 86% of all local water rights. They hold back water in the winter for storage in reservoirs including Prineville, Wickiup, and Crane Prairie, while releasing it from spring through the fall for use by irrigators. They also have rights to “live flow” during irrigation season. Live flow is water that has not been stored but is in the natural flow of a river such as the Deschutes or the Crooked.
As you can see in the chart above from the US Bureau of Reclamation, yesterday the live flow in the Deschutes just above Bend was 865 cfs. This is flows out of Wickiup combined with downstream tributaries and springs. After irrigation diversions in and around Bend, the flow was reduced to 98 cfs, meaning irrigators were diverting 767 cfs. 98 cfs is less than 10% of the historical flows in the Middle Deschutes. Two days ago the Deschutes below Bend was at a lethally low 48 cfs, about 5% of the historical level.
In 2 weeks the flows out of Wickip will be reduced to 100 cfs, the level that the irrigation districts have agreed to maintain throughout the winter as part of the Deschutes Basin Habitat Conservation Plan. Flows in the Crooked River out of Prineville Reservoir will be maintained around 50 cfs per the HCP agreement.
100 cfs from Wickiup is certainly better than the 20 cfs in the past, but it is still far from the level needed to maintain a healthy river ecosystem. The Middle Deschutes is in even worse shape as it’s historical flows were higher than the Upper Deschutes near Wickiup. The Oregon Department of Fish & Wildlife estimates that a minimum of 250 cfs is needed in the Middle Deschutes to have a healthy ecosystem.
50 cfs released from Prineville is also far below what is needed by fish and aquatic species. Also concerning is the dramatic fluctuations that can occur. In only a few hours on October 1, the river went from over 120 cfs, to 40 cfs, to 57 cfs. As I write this it is at 53 cfs. Talk about stress on aquatic species!