Indian Creek in Linn County gets new attention
Forming watershed authority under consideration
When it hasn’t been ignored, Indian Creek has been an afterthought the past 150 years — something to be bridged, channeled, and drained into.
It’s been getting more attention this year, and along its upper reaches some are starting to see the stream differently — as a sort of linear nature preserve through the heart of their city.
“As a city or neighborhood, we’re trying to take advantage of the green space along the creek, to make it an asset for our community and for the city,” said Rick Sandstrom of Marion.
Downstream in Cedar Rapids, residents who have seen its wilder side are wary.
“This neighborhood needs to give back to the creek what the creek requires,” said Marv Rops.
Rops, 79, has lived in the Sun Valley neighborhood, just upstream of East Post Road SE’s new bridge over the creek, for 30 years. Sandstrom, 64, was one of the first residents of the Creek View Coves development near Marion’s south city limit.
The two neighborhoods’ relationship to Indian Creek show 30 years’ evolution in design.
“It’s just an illustration of how poor some of the design is,” says Rops, a retired consulting engineer, pointing across his front yard to the creek 440 feet away. “This is all a flow area.”
At Creek View, half the development’s 36 acres are set aside as common green space, mostly along the stream. A pond catches runoff from pavement well to the east — it takes about three days for a heavy rain to percolate into the creek.
“That particular property actually has a pretty nice natural flow to it,” said Jon Dusek, president of Armstrong Development, Creek View’s developer. “We didn’t move a lot of dirt, and tried to use the existing topography. It saved us some money, but it also led to some good water flow — we got that directed right to the pond.”
The Creek View Neighborhood Association — Sandstrom’s the president — granted an easement for the city to extend a trail along the stream from Thomas Park. A bridge that will carry the trail over the stream is in place, and plans call for the trail to reach Highway 100 this year. Someday the trail will run from the Bowman Woods neighborhood to the north to Cedar Lake near downtown Cedar Rapids.
“We’re getting away from managing it as a storm sewer to managing it as natural resource, is what it comes down to,” Ryan Miller, Marion’s public works director, said of Indian Creek.
Much new interest in the creek can be traced to last November, when it was one of six Iowa streams or rivers named eligible for creation of a watershed management authority. Jointly controlled by representatives of local governments within the watershed, a watershed authority would have authority to adopt flood-plain and water-quality policies.
An Indian Creek watershed authority will be up to the local governments — Alburnett, Marion, Robins, Hiawatha, Cedar Rapids, unincorporated Linn County, and the Linn County Soil and Water Conservation District. Jennifer Fencl of the East Central Iowa Council of Governments said she’s drafting a proposed intergovernmental agreement for each council or board to vote on.
Whether or not a watershed authority is actually created, the pilot project meetings — the next one is 1 to 4:30 p.m. May 22 at Marion City Hall — have some of the creek’s neighbors debating its future and present-day land use.
“I’m approaching this a little bit as a watchdog,” said Curt Zingula, who farms more than 1,400 acres, many of them along Indian Creek. “There’s so many misconceptions about agriculture, myself and other farmers feel we need to be there at the table.”
According to Toby Hunemuller, chief of hydrologic engineering for the Army Corps of Engineer’s Rock Island District, about 24 square miles of Indian Creek’s watershed are developed, compared to about eight square miles in the 1960s. Development can contribute to flash flooding as gutters and storm sewers quickly drain into the stream.
Still, most of Indian Creek’s watershed remains farmland, which affects its water quality and flow.
Nitrate, the primary pollutant of concern for drinking water, is present, sometimes at relatively high levels, said Marty St.Clair, a Coe College chemistry professor. His students have sampled Indian Creek for 12 years as part of a summer research project.
St. Clair said nitrogen-nitrate levels at times reach 10 milliliters per liter, the federal government’s drinking water standard. He said it tends to peak in the spring, declining to about half the peak later in the summer.
“It’s like most streams in Iowa,” he said. “The major part of it is agricultural nitrogen — there’s a lot of 200-bushel corn upstream.”
St. Clair said the nitrates, a product of nitrogen applied to farm fields, are higher on the creek’s upper end, dropping below the mouth of spring-fed Dry Creek below the Linn-Mar campus.
The Coe students have also found e-coli, a bacteria from animal and human waste, but “it’s not a big issue,” St. Clair said.
“Kids are going to play in the stream,” he said. “Don’t let them drink it, and wash their hands afterward. “
Recent research tends to acquit tile drainage for a role in flash flooding, but agriculture does impact high-water flows.
While buried tile lines quickly drain farm fields, they also allow the soil to absorb more moisture. Heavy or sustained rainfalls overwhelm tiled and untilled fields alike.
When the watershed gets 7 inches of rain in two days, “then the characteristics of that stream are going to dominate,” Hunemuller told a watershed meeting in March. “Peak floods are surface-driven.”
Instead of debating tile, the question should be whether policy should encourage land owners to maintain wetlands, grassy strips along streams, and swales that can catch and hold rainfall said Keith E. Schilling, Iowa Department of Natural Resources research geologist , adjunct assistant professor in the Department of Geoscience at the University of Iowa.
“You’re not going to stop it when it gets to the city,” said Rops. “That’s an unstoppable force. You’ve got to stop it where it comes down. You’ve also got to compensate that landowner for the loss he has if he loses a crop one year.”
Zingula doesn’t expect Congress to make the money available compensate farmers for such conservation measures.
“How are you going to get people to participate and change the way you farm?” he said. “Congress is going to be doing away with farm payments.”
Meanwhile, Rops and his neighbors wait for the next downpour. During an unusually wet June 2002, three to four inches of rain in two days triggered a flash flood that caused $3.2 million damage, much of it in Sun Valley. Similar but less expensive floods came in July 2008 and August 2009. Hunemuller found record of 22 flash floods between 1937 and 1993.
The Sun Valley Neighborhood Association hired University of Iowa civil engineering professor Jacob Odgaard to study the situation in 2002. He recommended the city better maintain the stream banks, removing limbs and other debris that impede flow, and consider building a berm to protect Sun Valley and establishing retention ponds along the stream’s entire length.
“It was a matter of maintaining the channel,” said Odgaard. “Beyond that, it’s a matter of retention.”
The city has cleared the stream’s banks, but any structural solution awaits completion of a Corps of Engineers study that stalled when funding ran out.
“There’s been older reports that had numbers, but with the 2002 flood, the numbers didn’t seem to be correct,” said Dave Scanlan, Cedar Rapids stormwater manager.
Scanlan said the city has also planted native grasses along the stream, and it’s preparing a fix for the Sun Valley storm sewer.
Hunemuller the Corps and the city are negotiating the cost of completing the project, which will produce new maps for the 100 and 500-year flood plains.
Meanwhile, Indian Creek’s future is looking up. Marion has cleared its stream banks, too, and Miller said city crews are trying new ways to grade their slopes to prevent erosion.“There’s people that realize how much is down there,” he said. “We think if we introduce more ways for people to use the waterway, people won’t think of it as a storm sewer.”