No beavers? No dam problem

By Greg Lowell Redstone Review

LYONS – Prior to the coming of trappers in the 1820s, the Colorado landscape was markedly different. Beaver dams shaped ponds, meadows, and marshes to the benefit of fish and wildlife and conserved scarce water in their impoundments. But from 1822 to 1840, unregulated trapping decimated Colorado’s beavers, and by the end of that time, there was no longer a viable beaver population.

It’s hard to appreciate how much beavers shaped the landscape. Scientists calculate that up to 250 million beaver ponds once puddled the continent – impounding enough water to submerge Washington, Oregon and California.

The slaughter of beavers transformed Western waterways in a bad way. In a healthy, beaver-rich creek, dams slow water flows, capture sediment, and counteract erosion, according to a 2018 Science magazine article. But after beavers disappeared, streams eroded deep into their beds and lost the ability to spill onto their floodplains and recharge aquifers and dramatically increased flood damage.

Humans busy as beavers

Nowadays, despite regulation, beavers are still rare in Colorado and have never recovered to pre-1820s population levels, but research has proven that sometimes humans can replicate the beneficial environmental effects through devices called beaver dam analogs (BDAs).

Humans may not be as persistent as beavers, but through good science and mechanical efforts, imitation beaver dams are popping up throughout the western states.

BDAs, according to the Science article, are “perhaps the fastest-growing stream restoration technique in the West.” The U.S. Forest Service, The Nature Conservancy, private landowners and local conservation organizations have installed the structures to return life to deeply eroded streams.

The BDAs are constructed from rocks and timber in excavated channels that carry water from an adjacent river or stream into the floodplain. (An added benefit is that many times, beavers “adopt” the structures and improve upon them.)

Locally, the Watershed Center (www.watershed.center) has installed three BDAs along Left Hand Creek. The three BDAs are built in series on a side channel of creek, and generally run with water from spring until August. The ponds that are formed have many benefits. They store water for slow release back to river, capture sediment, provide seasonal wildlife habitat for fish and amphibians (particularly vernal pools) and act as fire mitigation.

The BDAs, as well as other work to restore a natural floodplain in the wake of the 2013 flood, was done in 2019 under an agreement with a local ditch company and private landowner.

Monitoring done at the BDA sites have shown the manmade structures are performing as planned. The vegetation around the ponds and wetlands also stays green most of the year (except in winter) and makes the area less prone to fire ignition.

Coming to Lyons?

The town-owned Martin parcel adjacent to Bohn Park was the subject of a December 9, 2022, visit by local government and fire district officials to assess its value for fire mitigation and to explore its eco-

The last few months have been tough on us crusty old Boomers with the loss of Jeff Beck and more recently David Crosby. But we have also lost Walter Becker of music that they choose are usually the early and well known pieces rather than their best work. Any one who frequented a disco in the 1980s would have danced to Jeff Beck’s Hey Ho Silver Lining but you might not have heard later masterpieces like Cause We’ve Ended As Lovers. That song showcases Jeff Beck’s mastery quite unlike anyone else who has ever played the guitar. The notes coax and sway with quiet whispers interspersed with breathtaking outbursts, caressing the strings with this fingers. He was the master of the “cricket.”

Musicians have been coaxing amazing sounds from a Fender Stratocaster since 1956, ranging from Buddy Holly to Jimmi Hendrix, but nobody could do the cricket like Beck. It involves giving a little twang to the tremolo arm (whammy bar to us guitar nerds) to achieve a strange gargling, purring sound. He could sneak these little effects into the most complex lyrical line. Go to Spotify, or preferably YouTube, and find Jeff Beck playing a live version of Brush With the Blues. It gives me the chills every time I hear it.

Steely Dan, and Chris Squire, the bass player from Yes. I met Chris Squire walking down a street in Windsor in about 1973 and I just about died. He was very charming and was keen to hear my opinion of their sound at a recent Yes concert.

I was blabbing so breathlessly that I couldn’t really make a rational description.

The radio news reports do their best to eulogize each of them, but the examples of logical values.

David Crosby had a long career in many bands including the Byrds and Crosby Still and Nash and their variants. But in the last few years he was reunited with his son and they discovered a musical cohesion that was very special when blended with Crosby’s inventive song writing. They formed a band called Crosby, Pevar and Raymond or CPR which produced many masterpieces during David Crosby’s twilight years.

When you listen to this generation of musicians there is much excellence to be heard but not the groundbreaking creativity that characterized previous decades. If you are 17 years old this year I fear that you are being short changed.

According to Jessie Olson, executive director of the Watershed Center, the general consensus was that the Martin site should be prepared to “receive flood and fire (both prescribed burns and wildfire) and enhance the ecological function of the site without negative impacts to communities and water supplies.”

The most realistic goal would be to improve the flood mitigation and enhance the ecology of the site through a series of BDAs and/or other features, such as braided channels, backwater, or off-channel ponds. The BDAs and other features could capture debris upstream during a flood to divert it from town infrastructure and create lush green wetlands composed of fire-resistant vegetation to deter the spread of fire.

The ecology of the site – already a haven for many bird species – would also be improved. The notional plan would be to construct an overflow channel at the South St. Vrain River that would receive water during high run-off or flood events, direct the water through the property in a series of BDAs, then allow the water to exit the property via an existing irrigation ditch that runs back into Bohn Park.

Funding for the project could come through use of the town’s existing wildfire mitigation fund to use as a match for grant money.

Although the project is still in its infancy, don’t be surprised at some point in the future to see ponds on the property that resemble the work of nature’s preeminent dam builder.