State officials are working to address a tension that has arisen alongside the growing popularity of stream restoration projects that aim to keep water on the landscape by mimicking beaver activity.
There’s no doubt that North America’s largest rodent is good for riparian ecosystems. By building dams that pool water, beavers can transform channelized streams into sprawling, soggy floodplains that recharge groundwater, improve water quality and create areas resistant to wildfires and climate change. Beavers create natural storage ponds in the headwaters which slows the rate that water is released and can help boost late-summer base flows and prevent downstream flash flooding. Basically, beavers rehydrate a dry sponge.
The engineers of the forest are so good at what they do that environmental groups sometimes copy beaver activity in stream restoration projects, building what are called beaver dam analogues. These temporary wood structures usually consist of posts driven into the streambed with willows and other soft materials woven across the channel between the posts. The idea is that by creating appealing habitat in areas that historically had beavers, the animals will recolonize and continue maintaining the health of the stream.
These types of low-tech, process-based restoration projects have been growing more popular in recent years in part because they are relatively cheap and because beavers — which were once hunted almost to extinction — are having a moment as more people recognize their many benefits to an ecosystem. But there is a growing concern that these projects, which often take place on small, headwaters streams, could negatively impact downstream irrigators.
Under Colorado water law, older water rights have first use of the river, and if these stream restoration projects prevent them from getting their full amount, it could be problematic. Some are concerned that if the projects create numerous ponds in the headwaters, it could slow the rate of peak spring runoff or create more surface area for evaporation, which could negatively affect downstream water users.
According to Kelly Romero-Heaney, assistant director of water policy for the Colorado Department of Natural Resources, some water rights holders are concerned that projects that mimic beaver activity could be considered an out-of-priority diversion of water.
“If that’s a diversion, then it would potentially need a water right or a plan of augmentation,” Romero-Heaney said. “I would say both the water rights community and river health community are collectively unsettled over the issue.”
This concept, taken to its logical extreme, raises the question: Could beavers need a water right?
Reducing barriers, protecting water rights
The issue cropped up at the Colorado Water Congress summer conference in Steamboat Springs in August during the meeting of the Interim Water Resources Committee, part of the Colorado state legislature. Terry Scanga, general manager of the Upper Arkansas Water Conservancy District, presented an overview of the issue to lawmakers. His district is home to a pilot project that aims to explore the risks of these stream restoration efforts to water rights holders.
“One of the big concerns is that in these types of stream restoration projects, as important as they are to the habitat and so forth, they can still cause impacts to water rights that are negative and actually depleting water to downstream users,” he said.
Sen. Jeff Bridges, who represents Arapahoe County, called the presentation strange and surreal.
“Who are we taking to water court in these cases if beavers move in?” he asked. “It seems to me beavers would probably have the most senior water rights of anyone in the state.”
DNR is currently working on a solution — which could take the form of legislation — to address the issue. The goal would be to reduce barriers to stream restoration projects while still being protective of water rights. If project proponents were required to spend years in water court securing a water right and spend money on an expensive augmentation plan, in which water is released to replace depletions caused by the project, it could have a major chilling effect on projects that nearly everyone agrees are beneficial to the environment.
“I think DNR’s concern is that if stream restoration projects end up routinely needing a plan of augmentation, that could be an insurmountable barrier, particularly for the low budget, low tech projects that are high in the watershed far from diversions downstream,” Romero-Heaney said.
Under current guidelines from the state Department of Water Resources, division engineers could issue orders to discontinue a diversion, release water that has been stored or clear streams of dams that restrict the flow of water if a project is causing injury to water rights.
No measurable harm
Jackie Corday, a natural resources consultant and former head of water resources for Colorado Parks and Wildlife, has been working on a study to engage West Slope agriculture in headwaters restoration. The study, commissioned by environmental group American Rivers, was funded in 2021 by a Colorado Water Conservation Board Water Plan grant.
According to a draft of a white paper Corday wrote as part of the study, her research did not find any documented cases where process-based restoration projects resulted in measurable harm to water rights from increased evaporation or riparian vegetation sucking up the water.
The goal of process-based restoration projects is to return conditions in the headwaters to what they were before waterways were harmed by mining, cattle grazing, road building and other human activities that may have confined the river to a narrow channel and disconnected it from its floodplain.
There are ways to ensure a project is done right and won’t harm downstream water users, Corday said. These include using aerial photography to make sure a project stays within the floodplain’s historic footprint and doesn’t create new wetlands; doing projects only on the upper reaches of small tributaries; making sure the structures are porous and will allow water to still flow through them; and creating transparency around the project by including local stakeholders and addressing their concerns.
“All indications thus far are that if properly done and in the right location, with the right design, no it does not decrease the streamflow to a degree that you could measure it at the stream gauge downstream of the project,” Corday said.
For now, DNR staff is continuing to gather information from stakeholders who have expressed interest in the topic, like environmental groups and Front Range cities, and deciding how to move forward. It’s very unlikely Colorado will see a beaver in water court. But there is a sense of urgency to resolve the issue, Romero-Heaney said.
Water managers are starting to see worsening impacts of climate change and wildfires on watersheds and water supplies, and how restoration projects can lessen those impacts. The western U.S. is also poised to receive money dedicated to headwaters restoration work from the federal infrastructure bill and the Inflation Reduction Act.
“That funding won’t be around forever,” Romero-Heaney said. “That’s where we have that sense of urgency of managing the barriers to stream restoration work in Colorado.”