Streamflow Partnership Supports Gold Medal Water

The Arkansas River is Colorado's longest reach of "Gold Medal" water - extending 102 miles and supporting one of the state's best-loved wild brown trout fisheries.  A key ingredient in the river's success: a cooperative flow management program to provide recreational flows in summer (the Arkansas is Colorado's most popular rafting destination) and stable flows for trout spawning and incubation through the fall and winter.

 
 
 Managing a drift on the Arkansas in Browns Canyon National Monument.

Managing a drift on the Arkansas in Browns Canyon National Monument.

VOLUNTARY FLOW MANAGEMENT PROGRAM

What makes the Arkansas River a Gold Medal fishery as well as one of the nation’s most popular rafting destinations? It’s all about managing the flows.

For decades, the Arkansas River offered poor fish habitat because of mining runoff at the headwaters near Leadville. The turnaround began in the early 1980s, when a federal Superfund designation at Leadville began the process of cleaning up the mine runoff. Then, 25 years ago, Colorado Parks and Wildlife, the Southeastern Colorado Water Conservancy District, Trout Unlimited and other users launched the Voluntary Flows Management Program (VFMP), an innovative program aimed at better managing water releases to meet multiple needs on the river, including recreational boating and fishery health.

The agreement was renewed in 2016 for another five years, said Drew Peternell, director of TU’s Colorado Water and Habitat Project.

The Arkansas River is somewhat unique in Colorado, notes Peternell.  “While many rivers in Colorado suffer low flows due to diversions for agricultural, municipal or industrial purposes, the Arkansas generally has more water flow than it would under natural conditions,” he says. That’s because the Arkansas receives transbasin water diverted from the Western Slope’s Frying Pan River—water diverted across the Continental Divide, then delivered down the Arkansas for municipal and agricultural use in eastern Colorado.   

“That extra water in the system gives Ark River water managers a margin of flexibility to tweak flows for optimal recreational use and river health,” says Peternell. 

Under VFMP, the water is released at the top of the valley, at Twin Lakes Reservoir near Leadville, and recaptured in Pueblo Reservoir downstream near Pueblo. From July 1 to Aug. 15, the VFMP manages the flows to provide at least 700 cfs during the height of the summer rafting season—a flow rate that makes most sections of the Arkansas River fun to raft.

The fishery benefits, too, from these infusions of cold, clean water to flush toxins and sediment and reinvigorate the habitat. For the fishery, the VFMP reduces and stabilizes flows at other times: in spring to accommodate the rearing needs of young brown trout, and in late summer and fall to support spawning and enhance the fishing experience of anglers.