Saturday’s Bulletin article titled “Deschutes River level to rise as irrigation season begins” was misleading on many fronts. It may be true that the river upstream of Bend begins to transform from a dewatered river to one of modest flows in early April.
However, the opposite occurs in the Deschutes River downstream of Bend. Flows in this reach drop precipitously each spring when irrigation districts begin diverting 90% of the river into their canals. The river upstream of Bend suffers a similar fate in November each year when flows below Wickiup Dam are reduced by 93%. Every year is a drought year for the Deschutes River below the dam and irrigation diversions.
The river rises in April when irrigation season begins, and water in Wickiup Reservoir is released, but the flow of 375 cubic feet per second (identified in Saturday’s article) is well below what is needed for our wildlife to survive. For example, the Oregon spotted frog during breeding season needs a minimum of 800 cfs in the reach below Wickiup Dam. The 375 cfs flow seems to be motivated more by irrigation demands and the fact that Wickiup is at an historic low level than it is for the health of the wetland habitat.
Oregon Water Resources Department suggested that “pushing too much water down the river at once can damage spotted frog breeding habitat,” which is misleading and counter to the biological opinion completed by the U.S. Fish & Wildlife Service (USFWS) last December. It says this about the river’s current state. “In the spring prior to irrigation season flow releases, spotted frogs breed in shallow water that is unvegetated. Egg masses are exposed to wind and high water temperatures in the shallow water. Adult breeding frogs are at risk of predation by herons and raccoons. The water’s edge does not reach the vegetation (where the frogs want to breed) until approximately 800 cfs.” This means that the 375 cfs has no chance to create suitable breeding habitat for frogs because it is too low, not too high.
Again, the USFWS biological opinion concurs. “Flow releases from Wickiup Dam in early April have the potential to improve breeding habitat but the flows are often not sufficient to provide for shallow water areas in contact with emergent vegetation. However, when the timing of flow releases is too late, weeks after the hatching of spotted frog eggs, emerging tadpoles are not likely to be within emergent vegetation and are at a high risk of predation.”
It is clear that in many parts of the Deschutes River, the Oregon spotted frog needs flows of 800 cfs to reach suitable breeding habitat.
The recently approved Habitat Conservation Plan limits flows to 600 cfs in March when breeding season starts and allows for flows as low as 400 cfs in an adaptive management arrangement. Only in April are flows allowed to reach 800 cfs, the minimum flow needed to reach wetland vegetation.
As Saturday’s article suggests, the river is rising but not fast enough or with the right timing to assure suitable breeding habitat for the Oregon spotted frog. We have waited for over a decade for the Habitat Conservation Plan to address the most urgent problems facing our river caused by irrigation management. The plan was approved late last year, but it is already showing its incapability to restore flows in the river to support the fish, wildlife and aquatic species of our wild and scenic river.