This week, a Colorado water court approved instream flow water rights for the lower Dolores River, protecting up to 900cfs during spring peak flows as well as essential winter flows on a 33-mile stretch of the Dolores River below the San Miguel River confluence. The state ISF right is intended to support river health and habitat for native fish, and also protects flows that support paddling opportunities.
The new in-stream flows for lower Dolores River can be monitored and enforced, thereby insuring long-term protections for minimum flows of 200cfs from March 16 to April 14; 900cfs from April 15 to June 14; 400cfs from June 15 to July 15; 200cfs from July 16 to Aug. 14; and 100cfs from Aug. 15 to March 15.
The new ISF rights are junior to all existing rights, which means that 900cfs may not be in the river when we have low snowpack like this year. The rights protect 900cfs from any future development, and dont do anything to restore flows below McPhee. Put another way, if there is 900cfs in the river after all existing diverters have taken their portion, no diversions that are junior to the ISF will be allowed to take any more water out of the river.
American Whitewater’s 2010 Recreational Flow Study for the Dolores River, identified 800 cfs as the minimum flow for rafting this section of the Dolores, and we are pleased that the State is protecting peak spring flows that also benefit whitewater paddling.
The Southwestern Water Conservation District which develops water for use in the region, filed a legal challenge to the in-stream flow rights arguing that the flows were too high. The SW District asked for a 1 percent depletion allowance on the in-stream flow to accommodate future development. The Dolores Water Conservancy District which manages McPhee Dam, also objected to the new Dolores in-stream flow right because it may limit future development needs.
If approved, the depletion allowance would be the first time in-stream flows are open to future carve-out – eliminating the long-term protections provided by these rights. The Court ruled against these proposed carve-outs, which is a big win for Colorado and for the River.