How healthy are our rivers?
It doesn’t require a degree in aquatic biology to realize there is something fishy going on at the confluence of Castle Creek and the Roaring Fork River.
Walk upstream just a few steps on Castle Creek and you’ll see some of the most clear, clean, inviting waters in the world. It’s so clean, in fact, that you can imagine the pure white snow melting high above timberline and feeding the stream. Just a bit of green algae covers the rocks on the creek bottom.
The Roaring Fork River isn’t exactly a roiling cesspool, either. Before warm temperatures melted enough snow to turn the river murky and turbulent, it was also running clear. But the contrast to Castle Creek was easy to detect, even for an untrained observer. The rocks in the Roaring Fork wear a thicker coat of algae and it is much darker than Castle Creek.
John Emerick, an aquatic biologist who taught for 23 years at the Colorado School of Mines in Golden, and Delia “Dee” Malone, a biologist and environmental scientist, have no easy explanation for the difference.
Emerick suspects the heavier, darker algae on the Roaring Fork indicates heavy loads of nutrients entering the river, perhaps from lawn fertilizers, street runoff and leaky septic systems.
“I see it as a warning sign that we’re probably overloading the river with nutrients,” said Emerick, who, along with Malone, is measuring conditions along the river.
If nutrients build to levels the river can’t absorb, then bug and fish populations could drop and the river could lose its intrinsic and economic value as wildlife habitat.
The valley’s lifeline
The river is a 60-mile lifeline for the Roaring Fork Valley, from the headwaters near Independence Pass to Glenwood Springs, where it joins the mighty Colorado River.
The overall Roaring Fork watershed is 1,451 square miles, roughly equal to the state of Rhode Island. The river and its tributaries total 1,962 stream miles, according to statistics researched by the Roaring Fork Conservancy, a Basalt-based nonprofit organization working to protect the watershed. The Fryingpan and Crystal rivers are among the Roaring Fork’s biggest contributors.
In an average year, the Roaring Fork basin will pump 307 billion gallons of water, or 943,000 acre-feet, into the Colorado River. One acre-foot has 325,851 gallons, enough to supply two average American families of four people for one year.
The rivers also make a huge economic contribution to the valley. Anglers and other tourists who visit the lower 13 miles of the Fryingpan River pump $2.6 million into the local economy, according to a study by the Roaring Fork Conservancy, by paying for lodging, food, fishing guides and other services.
The economic impact study also determined that visitors to Ruedi Reservoir added another $147,000 in direct spending.
No data is available on what visitors to the Roaring Fork River, including rafters, kayakers and anglers, spend locally.
Big impact from private land
The Roaring Fork Conservancy estimates that 75 percent of the Roaring Fork River’s watershed is public land, where land development doesn’t pose much of an environmental threat.
“The pressure on the remaining 25 percent, however, is enormous,” said the Conservancy’s latest newsletter.
The Conservancy and other environmentalists say major issues facing the river include:
– An estimated 15 percent of the water in the Roaring Fork basin is sucked through transmountain diversions that send water through the Continental Divide to thirsty Eastern Slope cities like Canon City and Pueblo. The watershed also irrigates 280,600 acres of farmland in the Arkansas River Valley. Sending the water east lowers flows in the
Roaring Fork and the Fryingpan.
– Ruedi Reservoir (on the Fryingpan) and Grizzly Reservoir (on Lincoln Creek, a Roaring Fork tributary) further control flows on the rivers. The dams provide flood control, but conservationists also lament that the rivers’ “signature” ” the seasonal fluctuations, flooding in the spring and drying out in the fall ” has disappeared.
– Housing development, of varying densities, lines the Roaring Fork River almost continuously from Tagert Lakes, four miles east of Aspen, to Glenwood Springs. Downvalley locations, like along Catherine Road, are being developed because of their proximity to the river. One new project, ironically called Roaring Fork Preserve, will actually chew up more land adjacent to the river.
– Residential development has brought manicured lawns right down to the river’s edge. Kentucky bluegrass has replaced the natural jumble of biologically-rich riparian areas in places like Upper and Lower River Road. These areas can be year-round wetlands or just flood plain, where traditional spring runoff flowed among willows, tall native grasses and other thick vegetation.
– Development and urbanization pose threats to water quality. The riparian areas are natural filters that absorb pollutants, like gas and oil residue from Aspen’s streets, fertilizers and herbicides from lawns and golf courses, and waste leaching from aging septic systems.
Emerick believes there is evidence that the river has been able to absorb the effects of mankind. Many measurements indicate that the Roaring Fork’s water quality is still high. But as the valley’s population grows ” from 8,000 people in 1950 to about 37,000 in the year 2000 ” he questions if the river can continue to dilute what we dump into it, and if it can support the number and diversity of creatures it does now.
Bluegrass versus riparian areas
The first thing many people do when they buy property next to the river, be it in Aspen, Woody Creek or the Aspen Glen golf club downvalley, is tear out the clumps of willow trees, mow down the tall native grasses and forge new access to the water.
Nothing could be worse, according to Alan Czenkusch, an aquatic biologist with the Colorado Division of Wildlife. Czenkusch gets the call when people want to stabilize a riverbank the proper way. Even the Aspen Center for Environmental Studies enlisted his help.
“The best way to manage a river is to stay out of its way and let it do what it wants to do,” Czenkusch said.
He also believes in leaving the riverbank alone. Most of the Roaring Fork Valley floor is comprised of mixed soils and cobblestones that lack any cohesion. The roots of willows and native vegetation stabilize the bank and help it resist erosion, according to Czenkusch.
Along the south side of the Roaring Fork River from its confluence with Castle Creek to Slaughterhouse Bridge are several homes at the river’s edge. A handful of homeowners have left the willows and towering blue spruce, the roots of which also cement the soils. But most homeowners have ripped out the vegetation for riverside patios. In many cases they strategically placed large boulders along the bank to stabilize it and prevent the water from eating away at their lawns.
The same pattern is followed along the entire course of the river, according to Malone.
She and Emerick helped create Big Country Resource Conservation and Development to assess conditions along the Roaring Fork, Fryingpan and Crystal rivers, and several major tributary streams, 240 stream miles in all. When the inventory is finished next year, Big Country hopes to educate governments on issues facing the river and help them find money for solutions. They also hope to educate homeowners on why wiping out natural vegetation harms the river environment.
Emerick said the river will gnaw away at the riprap and the soils behind it ” attempting, in its own patient way, to restore a natural setting. Eventually it will succeed.
“They might lose half their back yard, but it will repair itself,” he said, eying a property where the homeowners tried to conquer nature.
Czenkusch agreed that the boulders placed on the riverbank represent a short-term delay in the erosion process. A 100-year flood will send the boulders tumbling downstream, he said.
Meanwhile, the riprap has a detrimental short-term effect. Man-made barriers that prevent the river from spilling over its banks into the flood plain create a stronger flow in the main channel and allow the river to harness more power. When the river is allowed to spill its banks into lowlands, it dissipates its energy, easing the threat of destructive flooding.
In Czenkusch’s words, riprap and other barriers just tend to increase the stream’s “irritability.” That ultimately increases the risk of flooding downstream.
It’s not only homeowners whom conservationists are worried about. The Roaring Fork Conservancy is closely monitoring the town of Basalt’s work on a new riverside park. The Conservancy hopes that riverside work at the Levinson property is completed in a way that doesn’t exacerbate flooding problems downvalley.
Small space, huge value
Conservationists say the value of riparian areas is incalculable. Less than one-half of 1 percent of all land in Colorado is riparian, according to Tom Cardamone, director of the Aspen Center for Environmental Studies. Yet 80 percent of all nesting birds nest there and 75 percent of all native wildlife species spend at least part of their life cycle there, he said.
“That one-half of 1 percent is also the most desirable land to build a house and plant bluegrass,” Cardamone observed.
Man gets what man wants. The U.S. Environmental Protection Agency estimates that 60,000 acres of wetlands are consumed in the country every year. That rate of loss has slowed since it reached its height in the mid-1950s to mid-1970s, according to the EPA’s Web site.
Colorado is one of 22 states that has lost at least 50 percent of its estimated wetlands since settlement began by white men, according to the EPA.
Malone said the riparian areas are valuable because they serve as huge filters or sponges that protect water quality in streams. Water rushing down hillsides toward a river settles in the riparian zones and the sediments get captured, she said. In other cases, rising waters from a flooding stream flow into the riparian areas and dump fine sediments there. Willows in riparian areas even act to slow raging waters and absorb some of the river’s energy, she said.
Leaving a natural barrier between a bluegrass lawn and the river could also help catch chemical fertilizers, according to Malone. Cities and towns across the country are establishing ponds or wetlands where storm-water runoff settles before moving on to natural waterways.
Aspen uses a pond in Rio Grande Park and Jenny Adair Park to capture street runoff and filter it before it reaches the Roaring Fork. Basalt plans to create a similar pond on its Levinson property.
Water quality remains high
It’s easy to get worked up about effluent from worn-out septic systems or golf-course fertilizers, Czenkusch said, but fine sediments pose the biggest risk to water quality.
Fine sediments fill the small spaces and tunnels on the stream bottom beneath rocks. Those nooks and crannies are home to stonefly and mayfly larvae, macroinvertebrates that comprise a large part of the diet for trout, according to Czenkusch. Caddis flies, incidentally, tend to live on the tops of rocks.
Left to itself, nature finds a perfect balance ” “armoring” the river bottom to hold fast during high runoff, but not filling the nooks and crannies where insect larvae live, Cardamone noted. Even during spring runoff, when the rivers resemble chocolate milk, nature won’t line stream bottoms with fine sediments.
But erosion from improperly protected yards and at riverside construction sites can create problems by dumping soil into the stream, said Czenkusch. That’s why the barriers set up at construction sites near waterways are so important. Placed properly, they can prevent loose dirt from spilling into the river.
Fish counts remain high
Czenkusch has seen no evidence that fish populations on the Roaring Fork or Fryingpan rivers are declining, so he’s optimistic that the habitat remains “adequate.” It’s not optimum, however, “because of all of man’s activity,” he said.
“I think from a habitat standpoint, if anything was way out of whack we’d see it,” he said.
The Roaring Fork Conservancy has tested 24 sites along the river for the last five years. It looks for the presence of metals, nitrates and coliform that could pose threats to water quality.
“I think we’ve had good water quality and we continue to have good water quality,” said Rick Lofaro, Conservancy’s conservation director and supervisor of the water-quality testing.
Malone said the testing she does for the presence of insect larvae in the riverbed also indicates good health.
Czenkusch is somewhat skeptical about the wildlife division’s fish counts because they are just a snapshot in time. He places greater stock in the fact that he hasn’t heard complaints of declining fish populations from the numerous guides that work the rivers.
Tim Heng, general manager of Basalt’s Taylor Creek Fly Shop, said, “We’re catching as many fish today as we were 20 years ago.” He has been a guide since 1981 and has been fishing locally since the early 1970s.
One change, he said, is greater numbers of brown trout and fewer rainbows. Rainbows have a tougher time reproducing because they spawn in the spring, when runoff can scour the river bottom.
The lower section of the Roaring Fork River, from the confluence with the Crystal to the confluence with the Colorado, remains a “Gold Medal” trout fishing stream in the eyes of the wildlife division. The Fryingpan River below Ruedi Dam also holds that distinction. To earn it, there must be “60 pounds of trout biomass per surface acre” and at least a dozen trout over 14 pounds per surface acre, according to Czenkusch.
“In other words, there have to be a lot of fish and some of them have to be big,” he said.
Cardamone, who is all for letting nature set its own course, doesn’t believe valley residents have that luxury anymore if they want to maintain high water quality and premium fish habitat.
“We’ve unsettled things enough that we have to intervene to stabilize the river system,” Cardamone said.
Scott Condon’s e-mail address is firstname.lastname@example.org
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