Drake researchers inspect Frog Creek, make restoration plans

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Drake University environmental science and policy students Kathleen Knox, left, Devon Piersma, center, and Davis Horton will be on hand Saturday to cleanup Frog Creek. Volunteers are asked to meet at the Pattee Park tennis courts at 10 a.m.

Three Drake University students waded into Frog Creek Friday afternoon with GPS units in hand, looking for ways to improve the stability of the stream’s bank and its flow rate.

Davis Horton, Kathleen Knox and Devon Piersma are in the environmental science and policy at Drake, and their capstone class involves studying the restoration of Frog Creek.

The environmental science and policy program brings together teachers and students whose expertise and interests include water resources, geology, animal behavior, conservation biology, prairie ecology, entomology, economic and environmental modeling and climate change — a lot of science for a small creek.

“We’re the ones who get dirty,” said Horton, distinguishing the Frog Creek group from the Drake group studying Perry’s stormwater system.

The goal of the class, both for the Frog Creek students and those of the stormwater system, is to “complete a public research project or public service project for a stakeholder that gives them a very concrete, tangible deliverable,” according to Professor Keith Summerville, part of the program’s faculty and leader of the Drake project in Perry.

A storm sewer or field tile enters Frog Creek near Perkins park in Perry.
A storm sewer or field tile enters Frog Creek near Perkins Park in Perry.

Summerville said the Frog Creek group aims “to look at integrating the creek more fully into the cultural center and into the design of the city of Perry while also improving water quality and trying to restore it to a more natural condition.”

Frog Creek flows past Perkins Park and through Pattee Park, eventually meandering past the city’s wastewater treatment plant and then joining the North Raccoon River. The Frog Creek students hope to improve the habitat and water quality of the stream.

Perry City Administrator Sven Peterson said the Frog Creek project “will develop an ecological restoration and management plan that is responsive to 500-year flood events in Frog Creek.”

Frog Creek is too small to make the Iowa Department of Natural Resources (DNR) list of impaired waterways, but the North Raccoon River is on the list. The DNR list is updated every two years. In 2010 there were 446 impaired waterways in Iowa. In 2012 there 630, and in 2014 there were 725.

But nitrate pollution and bacterial contamination might not be Frog Creek’s biggest problems, according to Summerville, who studied zoology at Miami University in Oxford, Ohio.

“I think the primary problems in Frog Creek are sediment more than anything else,” he said. “Nitrate and the Des Moines Water Works lawsuit are in the news, but I think the problems with Frog Creek are more vegetation management along the banks, efforts to improve the fishery and sediment loading from erosion. Those are my assessments. I’m less concerned with the overall water chemistry.”

Frog Creek near Perkins Park has some sand and gravel in its bed.
Frog Creek near Perkins Park has some sand and gravel in its bed.

Horton, Knox and Piersma all mentioned vegetation management as one of the first steps needed in reducing soil erosion along Frog Creek.

“This would have originally been an oak savannah with a lot of native grasses,” Horton said Friday, as the group surveyed the creek north of Perkins Park and along the abandoned rail bed. The Altoona native said restoring some native vegetation is part of their restoration plan.

Knox said Iowa’s native prairie vegetation had deep and dense root systems holding the soil in place. Soil erosion and nutrient loss are a consequence of the intensive cultivation of only a few crops, such as corn and soybeans, instead of a wider diversity.

Frog Creek in Pattee Park is silted in with mud.
Frog Creek in Pattee Park is silted in with mud.

Knox, an Illinois native, also noted the meandering creek bed near Perkins Park contains some sand and gravel, but the straighter portion, running south from near W. Fourth and Pattee streets, is slower and more heavily silted in with mud.

Piersma said the Frog Creek group will also examine the feasibility of oxbow restoration along the creek, which fits the environmental science and policy program’s concern with animal reintroduction and restoration ecology.

The Topeka shiner is an endangered species of small minnow that lives in oxbows along the North Raccoon River, including Frog Creek, and fostering its population in on the group’s agenda, Piersma said. The Sioux City native said dredging oxbows adjacent to the creek might be one way “to improve the oxbow habitat that would be necessary for the breeding populations.”

Topeka shiner
Topeka shiner

The U.S. Fish and Wildlife Service added the Topeka shiner to its list of endangered species in 1998. The U.S. Environmental Protection Agency and the Iowa Department of Agriculture and Land Stewardship estimate about 50 percent of the Topeka shiner population has been destroyed by the faulty land use.

Creek restoration takes money, so the Drake students will also be looking for federal or state grants aimed at water quality and flood mitigation. Federal dollars in the Community Development Block Grant program are one potential source of funding, and state dollars in programs such as the Iowa Water Quality Initiative are another.

Iowa Secretary of Agriculture Bill Northey last week announced 13 new urban conservation water quality initiative demonstration projects were picked to receive $978,149 in funding. This brings to 45 the number of projects funded statewide in order to demonstrate water quality practices, including 22 urban projects, 16 targeted watershed projects and seven projects focused on expanding the use of water quality practices on the farm.

The Iowa Nutrient Strategy (NRS) estimated 92 percent of the nutrient pollution in Iowa’s rivers and lakes is traceable to agricultural sources, with the balance from urban areas. The Iowa Water Quality Initiative was established in 2013 to help implement the NRS, which is a plan for achieving a 45 percent reduction in nitrogen and phosphorus pollution in Iowa’s waterways.

The Frog Creek team from Drake is matched by a second team studying Perry’s stormwater system and looking for ways to improve it. Both groups might be eligible for grant funding as Iowa Water Quality Initiative demonstration projects. Some of the practices favored by the initiative include bioretention cells, bioswales, native landscaping, permeable pavement, rain gardens, sedimentation basins, soil quality restoration, wetlands and other practices, such as bioreactors and saturated buffer systems.

county gis aerial frog creek - smaller
Frog Creek in Perry. Source: Dallas County GIS

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