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.

Read more on AspenJournalism.com.