Dixon land restoration project aims to reduce flooding
Erosion control structures trap ‘thousands of tons’ of sediment during rains
An innovative erosion control project is underway on state land trust property just east of Dixon that aims to mitigate the effects of flooding, as well as limit the amount of sediment that enters the Rio Embudo and, ultimately, the Rio Grande.
“Something like a third of all sediment that goes into the Rio Grande — and overloads it — comes from the Trampas watershed and through the Rio Embudo,” said Jamie Tedesco, owner of Wood Sharks, the Taosbased forest restoration company that was awarded $359,000 by the U.S. Forest Service to complete the Lower Embudo and Copper Hill State Trust Land Collaborative Restoration Project.
Unlike other restoration projects Wood Sharks has completed, the current project focuses less on tree thinning and more on installing several types of erosion control structures built out of cut trees, branches, rocks and stones, and other natural materials. The goal of the deceptively simple structures is to slow down rain and snowmelt as it runs off the landscape and into arroyos, which have become increasingly narrow, deep and steep over time. The Dixon area also experiences regular flooding that threatens local farms, orchards and vineyards.
“When we build one of these one-rock dams, Zuni bowls, wicker weirs, contour logs, bush mats or log mats, we’re putting speed bumps down in the arroyos trying to slow down water,” Tedesco said. “Already in the last 50 years or so, so much of this landscape has eroded that the Rio Embudo and Rio Grande have a disproportionate amount of sediment coming from these hills that chokes the water and kills fish and other life in these rivers. And these communities are experiencing a lot of costs because of the excavation of sediment they have to do every year.”
The current project covers 230 acres of state trust land currently leased under an agricultural use permit, but another pending grant from the New Mexico Environment Department would expand the project over a total of 640 acres. So far, crews have installed around 250 structures, with at least 200 more in the works. Seed will be cast in the new year across areas where silt and sediment and debris has already built up behind structures.
About two dozen staff members with the State Land Office visited the site last Wednesday (Oct. 19).
“The State Land Office is working to help address the detrimental impact of heavy sediment flows to the Rio Embudo,” Joey Keefe, assistant commissioner of communications for the commissioner’s office, said in a statement. “Toward this end, the Land Office partnered with Wood Sharks and Ecotone to plan and install strategicallyplaced erosion control structures on state land near Dixon. Construction is ongoing. Funding for the project has also been provided by a Collaborative Forest Restoration Program grant from the U.S. Forest Service, which will complement funding from the New Mexico Environment Department to restore springs and wetlands on state land in the same area.”
Jan-Willem Jansens, owner of Ecotone Landscape Planning, said the overall project will help restore land that has suffered for about 200 years from the combined impacts of direct human activity, such as grazing, intensive harvesting of forest products and mining, as well as natural forces, like drought and changing precipitation patterns due to climate change.
“There is more recent erosion because of climate change,” Jansens said. “In the last 60-70 years, the Southwest has dried and the storms have become more intensive; more areas have burned. So all these things together on top of the historical ranches are now really conspiring to pretty severe, degrading forces. But you can do something about it. That’s what we’re trying to show here.”
In fact, some of the structures being installed now are deployed across earth that built up behind long-buried wicker weirs that were deployed during a similar project about 9 years ago.
“Those structures are still in place, and we’re largely building on top of that sediment to add another 1 or 2 feet on top of the old structures, which are mostly buried,” Jansens said.
He said they estimate their efforts are capturing “thousands of tons of sediment at this point in all locations, with the 250 structures. Some of the larger structures, where these arroyos are 10-15 feet wide, some of them may capture 5-to-10 tons of sediment and debris,” Jansens said. “It slows the water, it catches sediment behind it and makes the water infiltrate into that sediment and then it spreads that water out over the floodplains on either side. So what was a channel, the gully, is pretty much filled up with sediment and the water starts more meandering over to floodplain spreading out more, slowing down more, and infiltrating more.
“And that is basically where the plants have their roots,” Jansens continued. “So that very shallow topsoil stays wet and that feeds plants. And so that’s how you then get plants to grow back on those stream banks and flood plains, alongside an arroyo.”
The more vegetation there is on the landscape, the less severe the flooding.
“If there are no plants, there’s no organic matter holding that soil together and that leads to rapid erosion,” Jansens said. “Sandy soils are like a sieve and water goes through it very rapidly. Plants, with their roots, help create a living topsoil of microorganisms and matter that hold the soil together, holds water better and stimulates new plant growth. So we’re trying to reverse a degrading effect of soil degradation by stimulating new soil development.”