Here’s the release from the St. Vrain and Left Hand Water Conservancy District (Sean Cronin):
April 20, 2026
Agreement affirms no new on-river dam while preserving valuable water rights for community benefit
The St. Vrain and Left Hand Water Conservancy District has reached an agreement with Save the World’s Rivers that reaffirms a new path forward for its Coffintop Reservoir water rights—one that does not include construction of a large on-river dam.
The District was created in 1971, in part, to build Coffintop Reservoir on South St. Vrain Creek west of Longmont and upstream of Lyons, through a planned partnership with the U.S. Bureau of Reclamation. While the reservoir itself was never built, two water storage rights associated with the Coffintop Reservoir project remain legally valid today.
As a governmental entity, the District holds the Coffintop Reservoir water rights not for its own benefit but for the community’s. In 2024, as required under Colorado water law, the District filed a routine six-year diligence application in water court to maintain those rights. The filing prompted an environmental group, Save the World’s Rivers, to submit a statement of opposition, opening discussions between the two organizations about the future use of the Coffintop water rights.
“The Water Court process is complex, and at the onset we were uncertain what Save the World’s Rivers hoped to achieve through it,” said Sean Cronin, the District’s Executive Director.
“We are always watching proponents of dams,” said Gary Wockner, Executive Director of Save the World’s Rivers. “At the appropriate time, we seek to identify ways proponents can achieve their mission while not creating a new dam. We were generally aware of the good work being done by the District, but concerned about their plan to build Coffintop Reservoir and dam.”
Through dialogue, the District and Save the World’s Rivers found common ground. Cronin noted, “I met with Gary several times, and I gained respect for his organization’s objectives, and I appreciated his willingness to come to the table and talk through complicated issues.” Save the World’s Rivers learned that the District had been working for more than 10 years with the City of Longmont, Town of Lyons, Boulder County Parks and Open Space, local environmental organizations, and food producers to develop a strategy to best utilize the Coffintop Reservoir water rights – without building the actual reservoir.
The District and Save the World’s Rivers reached an agreement through the court process, under which the District agreed to forgo using the Coffintop Reservoir water rights for any new on-river reservoir, including Coffintop Reservoir, and for the expansion of any existing on-river reservoir. Instead, the District will return to water court with plans to use the water rights at alternative locations and in ways that align with community needs, and environmental and water management goals.
“It became clear through discussions that the District shared values around avoiding a new on-river dam while still meeting its mission,” said Wockner. “That made an agreement possible,” Wockner said.
District leaders emphasized that the water rights are held for public benefit and that the original Coffintop Reservoir concept no longer reflects the highest and best use of the resource.
“This is something we and our communities have contemplated for decades,” said Christopher Smith, President of the District’s Board of Directors. “The Coffintop project, as envisioned more than 50 years ago, no longer fits today’s needs or values.”
For more than a decade, the District has worked with community partners to explore alternatives that could use the Coffintop water rights, while also supporting increased stream flows during low-flow periods. The District’s development and implementation of these alternatives is moving forward with engagement from important partners, including the Town of Lyons and City of Longmont.
Town of Lyons Mayor Hollie Rogan welcomed the agreement. “St. Vrain Creek is the lifeblood of our town, and a large dam upstream was never embraced by our community,” she said. “We’re pleased the District will not pursue Coffintop Reservoir and look forward to continued collaboration.”
Longmont Director of Water and Waste Service Chris Huffer noted the long history between the City and the District. “The challenges around water have only grown more complex over the last 50 years,” he said. “The District has a solid water plan, and the City is an eager partner in realizing the greatest potential of these water rights.”
