From The Colorado Sun (Kevin Simpson):
This stretch of the South Platte and its world-class fishing have been damaged by floods, but borrowed root wads and other material could repair and protect it for years to come
Situated at 8,700-feet elevation in one of the largest plateau basins in North America, cradled by hills with snow-dusted peaks in the distance, this stretch of the South Platte owes its reputation to a combination of circumstances that create ideal habitat for fish — largely brown and rainbow trout but also species like kokanee salmon. They not only breed in sustainable numbers but also live long and grow to eye-popping sizes.
The stretch of river meanders through easily accessible flatlands between two reservoirs, Spinney Mountain to the northwest and Eleven Mile to the southeast, for three miles as the crow flies, though anglers walk its winding path for closer to five miles. But multiple floods over the past several years have chipped away at the banks and vegetation that provided safe harbor and attractive spawning grounds for the fish, threatening the optimal conditions.
Last month, Colorado Parks and Wildlife workers launched a project to restore the banks of this picturesque and prolific fishery in South Park, about 45 minutes west of Colorado Springs. And in a unique twist, the project was linked with another several miles away, focused on improving habitat for elk and mule deer.
Matt Kondratieff, aquatic researcher and stream restoration manager, already had done significant restoration on the Dream Stream back in 2013, but the project took a major hit months after its 2015 completion when a major flood ripped through the river and undid much of the work…
This wasn’t just any stretch of river. The Dream Stream ranks in the highest tier of Colorado fisheries, called Gold Medal waters. Those areas can produce 60 pounds of trout per acre, including a dozen that measure 14 inches or larger. Of the state’s roughly 9,000 miles of trout streams, only 322 miles meet those criteria — and this section of the South Platte exceeds the standards significantly.
“When we look at the Dream Stream numbers, the number of pounds per acre, we are 4.25 times the Gold Medal standards for biomass,” says Tyler Swarr, a CPW aquatic biologist whose territory includes the waterway. “And we’re almost five times the Gold Medal standard for the number of quality trout. So it’s a very robust fishery — really phenomenal, especially the brown trout population.”
The portion of the river that connects Spinney and Eleven Mile reservoirs now lies within what since 2010 has been known as the Charlie Meyers State Wildlife Area, named for the longtime Denver Post outdoors writer whose combination of eloquence and policy-minded conservation advocacy defined Colorado’s landscape. A memorial near the parking area celebrates Meyers, who died at 72 of complications from lung cancer…
Reality behind the dream
It may fly-fish like a dream, but there are plenty of reasons — both biological and hydrological — for this waterway’s abundance.
Start with Eleven Mile Reservoir, built in 1970. Lake species like brown and rainbow trout do well in the deep (more than 100 feet) and cool habitat, where they remain largely safe from predators and reside for most of the year — until it’s time to spawn. Then, they head upriver into the South Platte, where undercut banks provide further refuge while they pursue their journey to deposit their eggs in the river’s riffle habitat.
Riffles are generally shallower, faster parts of a stream where protruding rocks churn and oxygenate the water — which in turn aids water-dwelling insects, which become a current-driven buffet for fish. The gravel beneath provides the ideal repository for trout eggs.
Spinney Mountain Reservoir formally opened in 1982, providing a bookend to a remarkable ecosystem. The standing water of Spinney, plus gravity, creates groundwater movement that eventually rises into the Dream Stream from below — and the gentle upwelling provides prime conditions for trout eggs.
Too much sediment in a stream can smother them, but the rising water essentially cleans the gravel where the eggs lie and tumbles them in oxygen to enhance their development. Hatcheries replicate that natural water movement.
But as flooding washed away the river banks, once-prime spawning areas began accumulating fine sediment that hindered egg development. Left unrepaired, the stream would continually widen and become shallower. Water temperature would rise — a detriment to cold-water species like trout — and crucial hiding spots would disappear, exposing fish to predators from above…
Since water is released into the South Platte from the depths of Spinney, not the surface, the temperature remains hospitably cool, even in the heat of summer…
While Spinney also provides water to Aurora, the city has been accommodating in scheduling releases so that they don’t impact fish health or spawning — especially for the large population of browns in the area, notes John Davenport, chapter president for Denver Trout Unlimited.
“The way it has been managed and improved,” he says, “and with Aurora such a good partner to keep water flowing and take into consideration fish health, those fish grow large. If you’re not from Colorado, the Dream Stream will look nothing like your preconceptions. This is a meandering stream through flat, dry, sagebrush desert. It’s more like you’re on the plains than into the mountains. But as soon as visiting fishermen hook into big fish, they forget all about that.”
[…]
An unusual repair project
When Matt Kondratieff started formulating a plan for restoring the Dream Stream, he huddled with the project’s primary architects: CPW engineers, aquatic researchers and biologists Swarr and Spohn — people with decades of experience in the watershed.
He also consulted with several outfitters and anglers — including Landon Mayer — to fine tune the plans…
The project’s primary goal was to repair damage resulting from record high runoff in 2015, and two years later from a storm cell over the drainage that produced flash flooding. The use of toewood — a technique that employs submerged wood to reinforce the stream bank — would be augmented by other materials like cobble (basically rocks ranging from baseball- to basketball-size), large gravel and sod transferred from upland areas.
The area has a history of periodic flooding, often from localized storms that drench the region. One particularly freak storm just a few years ago dumped 3 inches of rain in less than an hour. Then rain turned to heavy hail and triggered a wall of water estimated at 10 feet high on the river.
What made the Dream Stream project unusual is that it fed off another CPW land management effort several miles away to enhance habitat for elk and mule deer. As the proliferation of mature conifer trees began to crowd out stands of aspen, a favored food source, crews worked in the James Mark Jones State Wildlife Area to thin the conifer.
“Bottom line,” Kondratieff says, “we needed large trees with root wads. So they figured out where there was overcrowding, took those trees and trucked them down. We used the root wad with the stem to weave into the banks, leaving root wads toward the channel, which creates complex habitat trout love.”
In all, workers moved nearly 60 15-foot tall trees, root wads still in place, four that measured 35 feet, plus 102 logs and more than 200 cubic yards of slash. Those elements were woven into the banks, while 15 tons of rock and boulders were strategically placed to enhance riffles…
By repairing the Dream Stream’s banks, CPW also aims to maintain a narrower channel that will effectively transport the fine sediment that can threaten egg-laying areas farther down the river to the next reservoir…
CPW research has determined that adding in-stream wood more than doubles trout abundance, as the root wads in particular provide cover for the fish to avoid predators, Swarr explains. Aside from anglers, the fish also must be wary of predatory birds that patrol the area, including eagles, herons, pelicans and osprey.
The project was funded largely by insurance money from the 2015 flood — about $60,000 — along with about $40,000 from CPW’s capital construction fund. Swarr estimates that to pay a private contractor for the work would have cost about $1.2 million compared to a little over $100,000 that it cost CPW to keep the work in-house, source materials on its own and combine it with the work on the department’s high-country project…
The heavy equipment required for the bank repair work is gone, but tracks remain as lingering evidence of the short-term disruption of the Dream Stream. Although plant life requires time to take hold and flourish — it could be a decade before it matures — the fish adapt quickly to the changes. Often it takes only days or weeks for them to adjust to the river’s new design, to discover new safe havens and food-rich riffles.
