If you’re an angler — or if you simply appreciate native fish — you know the importance of the bluehead sucker, flannelmouth sucker, and roundtail chub to the Gunnison River ecosystem. Soon these fish will be better able to move upstream to spawn, thanks to a project by the Western Slope Conservation Center and the North Fork Farmers Ditch Association to modernize the Farmers Ditch diversion and headgate structures. The project is one of eight Colorado projects receiving funding from the Bureau of Reclamation through the Bipartisan Infrastructure Law, with additional support from the National Fish and Wildlife Foundation and other funders.
The bluehead and flannelmouth suckers and roundtail chub are endemic to the Colorado River Basin, meaning they are found nowhere else. Together they play an important role in the river’s food web. By eating algae (as suckers do) or insects (in the case of chub), these fish convert the river’s natural food supply into their own biomass, becoming food for larger fish, birds, and other wildlife while moving nutrients up the food chain. However, their ranges have shrunk significantly as the basin’s rivers have been developed, and their populations have declined because of habitat loss and predation by non-native fish.
Replacing the diversion dam and headgate is important because the current structure — and the resulting quarter-mile of river that goes dry during summer — is a permanent barrier preventing fish from reaching spawning grounds. All three species are designated Species of Concern by the State of Colorado, which joined other basin states in 2006 to create the Three-Species Program to help avoid federal endangered species listings. Healthy fish populations benefit irrigators, anglers, and boaters alike by helping avoid future restrictions while maintaining a functioning river ecosystem. The new gate will reconnect upstream tributary spawning habitat that has long been cut off from Gunnison River populations. All three species are highly migratory, with some traveling more than 75 miles in a year.
Constructed in 1888 and appropriated in 1896, the Farmers Ditch is one of the oldest diversions on the North Fork. It stretches about 12.4 miles from northeast of Paonia along the bases of Pitkin, Stucker, Sunshine, and Powell mesas before ending north of Hotchkiss. Over the years, the diversion evolved from boulders cabled together to a concrete, rubber-lined structure with a slide gate installed in the 1970s. After 50 years of use, however, the system has become inefficient.
Today, the water commissioner must park on the highway, climb down a steep embankment to adjust the turnout valve, then drive downstream to measure the ditch’s output. If additional adjustments are needed, the process starts all over again.
Recognizing these inefficiencies and the barriers to fish passage, the Western Slope Conservation Center applied to the U.S. Bureau of Reclamation for funding in 2025. Additional supporters include the Delta Farmers Union, Delta County Board of Commissioners, Colorado River District, American Rivers Southwest, Delta Conservation District, and Colorado Division of Water Resources.
The new diversion will use an Obermeyer Spillway Gate System, a bottom-hinged steel gate supported by an inflatable air bladder. Compared with the existing weir, the Obermeyer allows remote, precise flow control and can send excess water downstream to benefit fish. It also improves fish passage by allowing managers to run “fishway attraction” flows leading to a fish ladder and eliminates the “suction trap” of older gates. The project also includes piping 1,600 feet of ditch and rebuilding turnout structures, reducing leaks.
A senior water right is only as good as the ditch company’s ability to deliver water. Under Colorado water law, the company must raise the river enough at the diversion to divert its full legal water right. Currently, operators stack 12-inch-wide wooden boards on the structure to raise water levels, and those boards remain in place throughout the irrigation season, even when flows increase, diverting excess water and drying a quarter-mile of river.
The Obermeyer gate replaces those drop boards with an inflatable rubber bladder that can be operated manually or automatically from a control house. Paired with a flow-measuring device, it ensures the full water decree is delivered while automatically lowering during higher flows so more water remains in the river.
Fish are not the only beneficiaries. Increased river flows will improve conditions for anglers and boaters, supporting local businesses that serve visitors. The project will also provide more reliable water delivery to approximately 100 farmers irrigating nearly 1,000 acres on the north side of the North Fork. Hydrologists have calculated the ditch’s current efficiency at 28 percent. While a 100 percent efficient system is impossible because some water is always lost to evaporation and seepage, the diversion improvements and pipe installation will reduce leaks and spillage, keeping more water available for agriculture while reconnecting the river downstream for recreation and fish.
Thank you to the North Fork Farmers Ditch Association, the Delta County Commissioners, and all the community partners who have supported this project. The new Farmers Ditch diversion and headgate will improve water delivery, efficiency, and administration of the water right while maximizing river water for both fish and people. Look for construction updates towards the end of the year, into early spring of 2027.
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