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By Jason Johnson
Sport fishing could soon be added as a campus activity thanks to a University of Northern Iowa (UNI) project to improve water quality on its 900-acre Cedar Falls campus. This work includes a series of stormwater management projects, including rehabilitation of a unique on-campus stream—Dry Run Creek, which flows through the northern part of campus.
The Iowa Department of Natural Resources (DNR) designated Dry Run Creek an impaired water body in 2002 after studies found a lack of aquatic species, including benthic macroinvertebrates, nearly microscopic “bugs” that lay their eggs in the bottom of healthy streams. According to Rebecca Kauten, Dry Run Creek watershed coordinator, benthic macroinvertebrates serve as a food source for fish, birds, and other mammals and are often indicators of good or poor water quality.
Further investigation found not only that hydraulic alteration from flashy, storm-related runoff events and sedimentation were reducing habitat but also that levels of E. coli bacteria were surpassing limits for safe human contact. In 2005, the Black Hawk Soil and Water Conservation District received a grant from the Iowa Watershed Improvement Review Board to install a series of structural best management practices to demonstrate innovative ways to improve and protect water quality in the creek.
Kauten says the university was already in the formative stages of what is now a campus-wide sustainability initiative. “It worked out that the timing of both efforts coincided,” she says.
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| With water temperatures barely in the 50s, Dry Run Creek
might mimic a cold-water trout stream someday. |
Mimic Cold-Water Stream
The portion of Dry Run Creek that runs through the UNI campus is cooled by hundreds of thousands of gallons of well water discharge from the university’s cooling system between April and October. The temperature of this water maintains a constant range of 56 to 59 degrees, helping the creek maintain a high, constant flow and a level of dilution that reduces impacts from upstream erosion.
With the cool water temperatures, Paul Meyermann, UNI assistant director for operations planning, knew Dry Run Creek could mimic a natural cold-water stream, with the potential of attracting sport fish such as smallmouth bass and trout. “More than 20 years ago several local environmentalists, including UNI students, promoted the exact same concept,” he says. “It just happened that the timing was right for it to occur now. The grant money was available, and all stakeholders were on board.”
Streambank Stabilization
Because of incised and eroded streambanks, it was important for Dry Run Creek’s banks to be sloped back, stabilized, and properly vegetated to limit the amount of sediment and pollutants running into the stream. A collaborative plan by Kauten and Urban Conservationist Wayne Petersen with the USDA Natural Resources Conservation Service (NRCS) began with land survey work by the NRCS. UNI grounds crew and fisheries technicians from the DNR then excavated selected areas along the creek. Streambanks were sloped back to a stable angle (3:1 or 4:1).
The newly sloped banks were reinforced with riprap and a product called A-Jacks to dissipate energy and prevent soil erosion. A-Jacks are stable, concrete armor units that are designed specifically for streambank stabilization and flow and grade control.
To provide vegetative cover, a fast-growing temporary rye seeding was established. A seeding of native grasses and a continued effort to maintain stable streambanks is the plan for spring 2008.
Fish Habitat
To provide fish habitat, crew members made areas along the streambank 6 to 8 inches deeper to accommodate fish hides beneath them. Bank or fish hides provide fish overhead cover. The UNI carpenter shop built the fish hides, based on DNR specifications, with lumber donated by the DNR.
Kauten says the idea for fish hides came from a late fall 2006 conversation she had with Petersen. “He and I talked over the idea, and the next day I contacted DNR fisheries staff,” she says. “Before we knew it, we were all gathered at the creek, walking the bank and talking over ideas.” After a few more meetings and planning sessions, plans were made to install fish hides.
The DNR collected temperatures every 15 minutes from June through October 2007. Based on those data, project leaders will know what fish will be stocked—if any at all. “There are currently some white suckers and chubs in the project area,” says Kauten. “A few folks claim to have seen bass and trout already, but it may just be wishful thinking.”
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| Rye seeding
provides temporary vegetative cover at Dry Run Creek. |
Water Monitoring
Kauten monitors the quality of parking lot runoff entering the creek with collection units from GKY & Associates that monitor the first flush of stormwater runoff as it flows from two parking lots on either side of the creek. Dry Run Creek runs between the Towers Complex parking lot and the Malcom Price Lab School parking lot. Based on data she has recorded, Kauten believes any fishing will be for sport only—catch and release. “As you might expect, we’re picking up oil and grease readings from both parking lots, but we’re also getting occasional PCB [polychlorinated biphenyls] readings for Aroclor 1254, which may lead to human health risks.”
A strategically placed rain garden, or biocell, captures stormwater runoff from the Towers Complex parking lot. Rain gardens are concave-shaped gardens landscaped with perennial flowers and native vegetation that soak up rainwater. “Based on what I have seen, no water or pollutants that enter the rain garden are directly reaching the creek,” says Kauten.
Dry Run Creek water monitoring is currently funded through December 2008.
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Rebecca Kauten collects water samples
from a first flush collection unit. |
Future of Project Site
The future of the project site is bright. Meyermann says the stream corridor offers an ideal opportunity to connect people with the land and water in a way that shows the value of the campus’s natural resources. “Instead of making an effort to avoid the creek, now you see people leaving the sidewalk and heading toward the water,” he says. Signs are posted to educate people about the creek restoration.
Meyermann was able to take the concept of infiltration-based practices, such as rain gardens, near the stream corridor and apply them to new projects on campus. UNI’s new library plaza, which appears to have merely an attractive paver block system, is really a stormwater treatment practice, permeable paving. Under the paver blocks is a 4-foot-deep rock chamber and sub-drain that treats rooftop and sheet flow runoff. In the past, this area was a highly unsafe ice dam, but it now infiltrates rainfall quickly and does not allow standing water or icing.
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| A permeable paver block system was
installed near UNI’s Maucker Union. |
“The work done on Dry Run Creek was the inspiration for our paver block system,” says Meyermann.
Kauten says Meyermann is doing a great job of bringing UNI grounds crew up to speed on low-impact practices. “His contact with various academic and service departments throughout campus have shed light upon our efforts in a way no other single person could,” she says. “We could not have done this project so successfully, if not for Paul.”
UNI is also home to two pervious concrete parking lots, one of which was poured in October 2007. The new infiltrating lot is adjacent to the University’s new McLeod Center athletic and event arena. These and other projects around campus are examples for students and the community at large to learn ways to build sustainability and work to improve water quality.
Jason Johnson is a public affairs specialist with the USDA Natural Resources Conservation Service in Des Moines, IA.
SW January/February 2008
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