Restoration project on West Fork of Dolores River benefits trout habitat, ecosystem as a whole
from The Journal
By Cameryn Cass Journal Staff Writer
Saturday, Dec 28, 2024 7:35 AM Updated Saturday, Dec. 28, 2024 7:39 AM
An area chapter of Trout Unlimited recently partnered with a landowner to restore a portion of the West Fork of the Dolores River their property borders.
The property is set off a bumpy dirt road that juts off from Colorado Highway 145, north of Dolores and surrounded by National Forest land. One may ask, why need restoration?
Besides the West Fork’s beauty, it’s the largest tributary of the Lower Dolores. It’s also home to all four kinds of trout, including the only one native to Colorado, the cutthroat.
“Our focus starts with trout,” said Dolores River Anglers conservation chair Duncan Rose, who spearheaded the project.
“But it’s really about watershed health, which is also about forest health. You don’t have a good watershed unless you have a good forest, and you don’t have a good forest unless you have a healthy watershed,” Rose said.
Over time, modern practices and a change of land use along the riverbanks – such as ranching, grazing, or simply cutting out big fields – has resulted in less and less “large woody debris” falling into the river, Rose said.
That debris is not only a source of food, it also can be something of an anchor to slow down the water flow, and to offer fish and other critters a refuge.
In effect, the restoration project was in the name of something Rose called “structural complexity.”
“That’s the most important term you’ll pick up in this whole project,” Rose said. “If you don’t have complexity and have homogeneity, you don’t have the richness you need to accommodate all of the aquatic co-evolutions.”
To create this structural complexity – and put simply – the project involved strategically arranging big boulders in different ways and places along the stretch of river.
The untrained eye would hardly notice, but “it has tremendous impact,” Rose said.
“Aquatic habitat is built around complexity. The more complex it is, the more niches there are for the whole ecology of the stream,” he said.
“Structural complexity strongly reinforces trophic, or food chain, complexity. The two are flip sides of the same coin,” he added.
The team brought in an excavator to place these “gigantic” boulders weighing upward of three tons along the edges of the river in formations that look like a “J.”
They’re called j-hooks with vanes, and the team installed four of them.
J-hooks help redirect the thalweg – the stream’s center line of maximum force – to the middle of the river so it doesn’t flow and crash into the banks.
“Streams naturally meander. That’s a healthy stream, particularly in the flatlands,” Rose said.
But when it meanders, it wipes “out a bank that’s putting sediment into the river, which is not in and of itself a problem,” according to Rose.
“But there are habitations along the river in this particular area which are threatened by that,” he said.
To be sure, the j-hooks – complete with vanes to tie rocks to the bank so water can’t get around it – protect the riverbanks where fish spawn and animals hunt.
Additionally, it scours out a deep pool and scours out a very deep pool right inside that hook, Rose said.
Although there’s no real data to support just how much this type of restoration work positively impacts trout populations, anecdotally, it’s a success.
Rose said Trout Unlimited helped install j-hooks at another property, “and practically overnight, more fish came in.”
That’s because fish will stay in habitats they feel are “rich.”
However, j-hooks and vanes aren’t the only tools in the restoration toolbox, and they weren’t the only things installed at the West Fork property.
Trout Unlimited, which the Dolores River Anglers belong to, also put in 30 rock clusters and a rootwad.
Rock clusters are “basically doing same thing j-hook is, but on a microscale,” Rose said.
“Any healthy stream, when you look at it, should have large boulders, medium-sized boulders, small boulders, big cobble, little cobble. And some kind of tree, particularly those that could directly fall into the streams,” he said.
So they placed the 30 rock clusters in such a way to break up the stream’s flow and to create more trout habitat with the subsequent scouring.
Rose said the rootwad is “exactly what it sounds like.”
“It’s the root zone of a tree,” he said.
That root zone “has an awful lot of intertwined material,” he said.
“It’s a terrific refuge for very young trout because they can get into that mixture of material,” he said.
The j-hooks, vanes, rock clusters and rootwad all make up what Rose called “process-based restoration,” a relatively new approach to rehabilitating rivers.
“The goal is not to restore a characteristic, but to restore processes that create and maintain characteristic forms,” said Rose. “Instead of putting a whole lot of money into forcing it into something, let’s focus the processes to get them to do the work.”
Not only does this mode of restoration go along with – instead of fighting – natural processes, it allows streams to take care of themselves in the long run, which saves money and mitigates human intervention.
“Let the water do the work rather than physical, hard structures,” Rose said.
The whole project took three days.
And now, coupled with a recent 300-acre easement between the Montezuma Land Conservancy and a private landowner, over 5 miles of the West Fork are now protected or rehabilitated.
for photos of the work on the river go to:https://www.the-journal.com/articles/restoration-project-on-west-fork-of-dolores-river-benefits-trout-habitat-ecosystem-as-a-whole//?utm_medium=referral&utm_source=shareArticleButton&utm_campaign=shareArticleButton
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