Earlier this year, sampling in Coldwater Creek revealed about 2,500 brown trout per mile — a vast improvement from years past when no brown trout could be found in the creek.
Looking into the creek now provides a clear view of trout, a clean gravel bed and a variety of green-hued submergent vegetation.
True to its name, the cold, clear waters of Coldwater Creek flow through the undulating, cavernous landscape of Winneshiek County in northeast Iowa. Unknown to most passersby, beneath this farm lies Coldwater Cave. With more than 17 miles of passages, it is Iowa’s largest cave and designated a National Natural Landmark by the U.S. Department of Interior.
Thanks to this unusual topography, water in the creek bed can be elusive in certain stretches as it flows above- and belowground, depending on time of year and amount of rainfall. In one spot, Coldwater Creek emerges from beneath a large limestone face.
The beauty of the landscape makes it hard to believe that just six years ago, this creek was plagued by impairments all too common in waterbodies across Iowa: high bacteria counts coupled with excess nutrients and sediment. The Winneshiek County Soil and Water Conservation District took the lead and applied for funding to improve both Coldwater and neighboring Pine Creek, creating the Coldwater/Pine Creek Watershed Project.
In 2005, funding was secured from the Iowa Department of Agriculture and Land Stewardship’s Division of Soil Conservation, the Water Quality Protection Fund, and the Watershed Protection Fund, with the overall goal of reducing the environmental impairments.
Soil-saving practices used
The funds allowed the Winneshiek SWCD to begin working with area landowners to implement conservation practices throughout the 22,213-acre watershed. With a variety of practices available at 75% cost-share, these efforts have been extremely successful.
Project coordinator Corey Meyer says a combination of 16 practices were applied, including nutrient management on 2,000 acres, 12 manure management systems, 75 acres of grassed waterways, 24.5 acres of critical area seeding and nearly a mile of terraces.
More than two miles of the creek were fenced off from livestock, helping to reduce direct deposit of bacteria into the stream. More than 80 acres of woodland were enhanced with Resource Enhancement and Protection funding.
The landscape presented some challenges, one of which yielded an unusual but effective best management practice: sinkhole filter strips. Meyer explains, “The karst landscape in this area means sinkholes are prevalent. Sinkholes provide a direct route for pollutants to reach groundwater, so it’s vital that the sinkholes are protected.”
The grassy strips do just that, acting as a buffer for the sinkholes by slowing down and filtering any runoff from the surrounding farmland. Trees dot the strips, which tell the locations of the sinkholes, says Meyer.
Keep sediment out of creek
The upland work, sinkhole filter strips and all, has helped keep well over 6,000 tons of sediment each year (the equivalent of more than 400 truckloads) out of Coldwater and Pine creeks. Less sediment means improved water quality and a cleaner streambed, much to the satisfaction of the trout that now spawn in Coldwater Creek’s gravel streambed.
The population of brown trout is now naturally reproducing and self-sustaining, according to Bill Kalishek, fisheries biologist with the Iowa Department of Natural Resources.
He says brown trout have not been stocked in the creek since 2002. Yet, an early-October sampling of the stream produced several fingerling brown trout, providing evidence of the natural reproduction that’s boosted the population.
The creek is being stocked with rainbow trout for catching, which Kalishek says has helped protect the brown trout population.
More work is done
On top of the upland work in the watershed, funds from the U.S. Fish and Wildlife Service were used to improve fish habitat and stabilize the streambank. A portion of eroding streambank was regraded, and hides were installed, giving fish 2 feet of shade and shelter off the main channel.
Pleased with the results of all the work completed, Kalishek makes sure to praise all the efforts. “It’s not just the instream work we’ve done,” he says. “It’s the farmers who have adopted conservation practices on the land that has really improved the watershed.”
Jim Gillespie, interim director of IDALS’ Division of Soil Conservation, had the opportunity to take part in the recent sampling with the Iowa DNR. Seeing for himself the end results of a successful watershed project, he notes, “Landowners in the Coldwater and Pine Creek watershed should be commended for their commitment to protecting this stream and the watershed that drains into it.”
The leadership of the Winneshiek Soil and Water Conservation District is also recognized for providing the needed technical resources and financial assistance to implement practices in the watershed that made the largest impacts on water quality.
“This project is a prime example of how landowners and farmers can implement good land stewardship and remain sustainable in their farming operations,” adds Gillespie.
Partners of the $1.4 million project also included the USDA’s Natural Resources Conservation Service in Iowa, Northeast Iowa Natural Resource Conservation and Development Council, the Upper Iowa River Watershed Alliance, Izaak Walton League, the Driftless Area Trout Unlimited chapter, and Pheasants Forever.
Asberry is a program planner with the Division of Soil Conservation at IDALS.