Beavers and the Dams They Build Can Improve Water Quality

A bit of a trouble maker, beavers do help improve ecosystems and they potentially play a key role in water quality improvement.

A new partnership between Iowa State University Extension and Outreach, the Department of Natural Resource Ecology and Management at Iowa State, and the Iowa Nutrient Research Center will study the water quality and quantity impacts of beaver dams in central Iowa, and how effective these dams are at reducing nitrogen and phosphorus concentrations in Midwest agricultural watersheds.

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You don’t say. Color me surprised. I thought they only did that in Rhode Island and New England, and Cornwall and Washington. I didn’t know they did it in Iowa too!

“Beaver dams have been studied heavily for fish and wildlife habitat, but there’s been limited research on how these dams impact nutrients and flooding in the Midwest,” said Billy Beck, assistant professor and extension forestry specialist at Iowa State University.

Beck is studying the nutrient reduction potential of dams in central Iowa, and results will be provided to the Iowa Nutrient Reduction Strategy science team. The data will be used to help clarify the influence within the stream channel and the processes associated with in-stream nutrient loss on watershed-scale nutrient loads.

Oooh I have a guess about what you’re going to find. Call on me!

Shelby Sterner, an Iowa State graduate student studying environmental science, is tasked with leading the study, which entails elements of forestry, hydrology, biogeochemistry and fluvial geomorphology (how water shapes the earth).

The overall goals of the project are to identify and quantify key nutrient removal processes associated with beaver dams in central Iowa, and estimate the potential impact of dams on watershed-scale nutrient loading within the agricultural Midwest.

Beck said he understands the frustration landowners often have with beaver dams. He’s not looking to promote them – per se – but he believes with some balance, they can be beneficial.

HAHAHA. Sure they might do good things, but that doesn’t mean we should LET them for god’s sake, Be reasonable. I’m not a monster.

Baby steps. Iowa. Baby steps.

It’s here! It’s HERE! The real president’s day! If you missed the memorial last night you should really watch, and assuming anyone has time amid all the champagne corks popping, there’s some excellent beaver news for us to follow.

Beaver dams: Nuisance or conservation practice?

The beaver is often thought of as an industrious construction expert with instinctive engineering skills that creates dams capable of holding back the flow of water in Iowa’s creeks and streams.

For some, this skill is not as welcome as you may think. When a beaver’s dam backs water into a row crop field during a weather event or wet season, farmers are not their biggest fans. In addition, beavers have a voracious appetite for almost anything that grows, including corn. The combined nuisance of crop pilferage and field flooding creates a negative perception of beavers among most farmers.

However, beavers do play an important role in creating habitat for other wetlands creatures through the creation of natural ponds. And the slowing of water flow is one potential remedy for erosion and downstream nutrient transport issues facing Iowa. An additional upside of beaver dams is there is no construction or implementation cost for the farmer.

Finding a balance between these potential conservation benefits while paying attention to farming interests may be a daunting task, but as with most complex challenges, the first step is gathering data for analysis.

Oh don’t you just love it when farmers scratch their heads and say “Gosh that tarnation beaver dam might just be savin’ the water I need!” I have to admit I’m a big fan of these moments where the pest becomes popular. Aren’t you?

In Iowa, beaver dams are protected from destruction or demolition, unless it is done to protect the owner’s property. During a 2018 Iowa Learning Farms conservation listening session with farmers participating in watershed improvement projects, one farmer related a story about how they had handled a beaver dam issue on his farm.

He remarked that after the beavers were forcefully encouraged to move a dam downstream to reduce field flooding, he participated in nitrate testing above and below their newly constructed dam. To his amazement, the nitrate levels in the water were measured to be some 90% lower below the dam than above.

“Practices which help to move water off cropland as quickly as possible have helped farmers increase yields and put more acres into production, but in many cases at the cost of topsoil and nutrient loss to our waterways,” Beck says.

“There has been tremendous effort invested in research and practice aimed at conserving soil, and slowing or preventing nutrients from degrading water quality,” he says. “One area that hasn’t had a lot of critical study in Iowa is the potential efficacy of beaver dams as a conservation practice or structure that could naturally contribute to the recovery of compromised waterways.”

Get the hell out! You mean the report that beaver dams remove 41% of nitrates is actually true! Who cam believe it?

“We hope to be able to quantify the impacts to water quality provided by beaver dams,” Beck says. “We do understand that these creatures don’t always put their dams in the most beneficial sites from a farmer’s perspective. Finding measurable factors that can be analyzed from a cost-benefit angle may influence how farmers view and interact with beavers in their area.”

The likelihood of finding the perfect location for every beaver dam — one which maximizes benefits to all — is relatively low. However, reaching a better understanding of how these natural structures fit into a multifaceted approach to water quality improvement and conservation may contribute to overall progress toward statewide nutrient reduction goals.

Well that sounds like an EXCELLENT research project. I can’t wait for you to reconfirm the results they found in every other state and Canada. Now I have an inauguration to go watch.

I can’t believe how much I need this.