Marion flood map changes fuel watershed concerns

Sherri and Dave Evans built a house in northwest Marion in 1998, when Newcastle Road was surrounded by fields, next to a tree-lined waterway called Dry Creek.

The creek is now called Christopher Creek, and if it was ever dry, it surely isn't now.

Standing next to the swiftly-flowing water behind her backyard, Sherri Evans said new development on all sides has decreased the ground's ability to absorb rainwater and made the creek more volatile. Her complaint coincides with the looming April 5 effective date of new flood insurance rate maps, on which her home touches the 100-year flood plain.

Sherri Evans's flood insurance premiums may triple, and she argues it isn't necessary.

To the east, red backhoe arms hang motionless in the air above a field of bare, black dirt that will soon be another subdivision. Developers are building 82 homes to the north across Robins Road next to a giant retention basin, and to the west, earth-moving machines transformed the field along the creek into a plateau for two-story homes.

“They're just towering over the creek,” Evans said of the homes. “And that was just level land over there. It's a frustration.”

The Evans home, which Sherri Evans owns and rents to her quadriplegic ex-husband, Dave Evans, is among 700 Marion homes that will move in or out of the high-risk flood plain, but their case is unique.

Dave Evans was paralyzed in a bicycle accident in 1998, and needs a device to breathe. The house was built specially for him. It has an elevator, generators, a ceiling lift and voice activation controls for lights, doors, electronic equipment and window blinds. The basement is finished and opens onto a backyard ringed by a sidewalk. Moving would be difficult for him, and shifting into the flood plain could eventually cost an extra $1,094 annually in flood insurance premiums.

Dan Whitlow, Marion's city engineer, said the changes in the flood plain maps have nothing to do with residential development. FEMA largely used information gathered in 1982 to develop the flood maps, he said, and the city of Marion provided some input.

Detailed flood plain studies are expensive, costing up to $15,000 per river mile, Bill Cappuccio, a flood plain management engineer for the Iowa Department of Natural Resources, said of using the 1982 data.

“It's pretty costly,” Cappuccio said. “The idea of getting a detailed flood plain study for the entire state is unlikely.”

In FEMA's recent map modernization program, which is wrapping up in Iowa now, surveyors only did 17.4 miles of detailed flood plain study in 40 counties.

Whitlow said Marion's comprehensive plan calls for the area around Christopher Creek to be covered in subdivisions, and pointed out that all the homes, including the Evans home, contribute to storm water runoff. Flash flooding, however, happens only when it rains a lot, very quickly, he said, which has little to do with whether homes and yards absorb rainwater.

“The flooding is occurring in those high-intensity storms,” Whitlow said. “The permeability of the surface is no longer a factor when you've reached the saturation point.”

Along Newcastle Road, 11 homes will leave the flood plain and only two will move into it, Whitlow said, backing up his point that development has not forced more homes into the flood plain. But farther downstream, about 20 homes in Cedar Rapids city limits will soon be in the high-risk area, and another 10 in Marion will move into it north of where the creek flows under Boyson Road and empties into Dry Creek, which empties into Indian Creek a half-mile farther east.

Rich Patterson, longtime director of the Indian Creek Nature Center, and an advocate for better watershed management, said it's no secret that urban development causes flash flooding. His office overlooks the spot where Indian Creek rushes into the Cedar River southeast of Cedar Rapids.

“What happens in Marion has great effect downstream,” he said. “Therein comes the ethical end of this. Is it ethical for me to do something on my property ... that maybe is advantageous to me but hurts people downstream.”

Prairie grass with roots 10 feet deep stores rainwater in the soil and helps it trickle into the aquifer, Patterson said, but developers often strip the topsoil, remove trees, bring in fill dirt, pack it down, and then “carpet” the land with new sod that's impermeable to rainwater.

“It runs off just about like asphalt,” Patterson said.

The city of Cedar Rapids and Army Corps of Engineers have signed on to a $400,000 flood-control feasibility study of the creek's watershed. The new flood insurance maps are scheduled to go into effect April 5, but Rep. Dave Loebsack has asked FEMA to push the date back. The new map would change the status of 1,900 properties in Cedar Rapids.

Those properties moving into the 100-year flood plain can save on premiums by purchasing flood insurance before the maps go into effect, though in most cases the premiums will still go up significantly.