I write a lot about irrigation flows and its impact on local rivers, but today’s graphs once again illustrate the point. Irrigation season is underway with 25% of the water being delivered. This will be ramped up to full delivery by mid-May. Above is the Bureau of Reclamation chart for the Deschutes River at Benham Falls. It shows a relatively measured increase in flows, an increase that has generated sediment in the river but not extreme levels. In contrast, look at the chart for the river below the final irrigation diversions at North Canal Dam.

On April 13th around 6 pm the flows were at 135 cfs. Only 8 hours later they had increased to 247 cfs. There are no endangered species in the river below Bend, so there are no protections given to aquatic life. Once full irrigation deliveries are made the river will drop to around 130 cfs, which will not create sediment but will dramatically increase water temperatures during the hot summer months.