Cautious steps to handle runoff

Cautious steps to handle runoff

June 10th, 2010 by Pam Sohn in Green

Staff Photo by Dan Henry/Chattanooga Times Free Press - Chattanooga public works employees work to improve stormwater drainage on Winding Lane near Hixson on Thursday.

Staff Photo by Dan Henry/Chattanooga Times Free Press...

Building in Chattanooga for decades has involved clearing and reshaping land, cutting into hillsides and paving over acres of property.

But with state and federal regulators pushing cities across Tennessee and the nation to retain at least an inch of stormwater runoff onsite, it no longer will be enough to bury giant stormwater runoff pipes at low spots near city slopes such as Cameron Hill, Stringers Ridge or the rolling hills of Hixson.

"We need to think of it (rainwater runoff) in a way that more closely mimics nature," said Karen Hundt, director of planning and design at the Chattanooga-Hamilton County Regional Planning Agency. "We can't keep flushing if off all our parking lots and out to the sewage treatment plant to treat it all. Some day we're going to run out of capacity. Sometimes, we already do."

When that happens, it threatens Tennessee River water quality and raises health concerns, according to regulators.

But rising stormwater fees and concerns about possibly costly fixes already have sparked controversy and prompted the Chattanooga City Council to compromise on planned increases to the fees.

In October, the city announced that stormwater fees were tripling from $3 to $9.60 per month for residential property owners. City officials also also announced that nonresidential users -- businesses, churches, other institutions -- would pay $9.60 a month. However, after months of debate, the city dropped the rate $6.15 per month per equivalent residential unit, which is based on the size of the facility when compared with residential houses.

Mayor Ron Littlefield said the city must get into compliance with current and future stormwater regulations. A short-term solution is the city's new proposed rate structure for stormwater fees, which offers credits to nonresidential users for "doing the right thing" and finding creative solutions to their problems, he said.

The long-term goal is rewriting the city's land-use policies and, within those policies, including some new provisions for green infrastructure.

"I know from experience that's not a short process," Mr. Littlefield said.

Local developers care about the environment, said Dale Mabee, who 15 years ago developed the first local open-greenspace subdivision at Heritage Green in East Brainerd. And they know about the area's normal 54 inches of rain a year, he said.

The two big questions, Mr. Mabee said, are how new technology and design costs will fit with affordability and customer acceptance.

"Most builders will build the product the consumer wants, and once something is accepted by consumers, most builders are going to build it," he said. "At Heritage Green in East Brainerd, I built narrower streets and had more green space that absorbed more runoff, but it was a little before its time. Consumers hadn't caught up with it. Some are still not quite there."


David Crockett, director of Chattanooga's Office of Sustainability, is charged with helping meld change into shared vision.

What many people still don't understand is that the change isn't necessarily more expensive, nor does the requirement to hold one inch of rainwater onsite apply only to Chattanooga's new development, he said.

"Charlotte's stormwater fee is $9.12 (when calculated in the same manner as Chattanooga's) and Gainesville, Fla.'s is $11.15," he said. "Until the last year, that meant Charlotte's was three times higher and Gainesville's nearly four times higher than Chattanooga's $3 per month."

Even with the recent rise in Chattanooga's rate to $6.20, the other cities' rates are much higher, he said.

Mr. Crockett views the change as more opportunity than obligation.

"Using green infrastructure or high-performance landscaping increases the value, appearance and appeal" of properties and business districts and communities, he said.

In Philadelphia, Pa., a study found that property values in the city were estimated to increase 18 percent over 40 years "from just the above-ground, green infrastructure approach," he said.

Mr. Mabee said he has sat in on some of the educational talks Mr. Crockett has been making throughout the community about the proposed changes. He said he found the information "very intriguing."

Highest monthly

non-residential sewer rates

* Chattanooga non-residential -- $6.20

* Charlotte non-residential -- $9.12

* Gainesville, Fla., non-residential -- $11.15

Highest monthly

residential sewer rates

Charlotte residential -- $9.12

Chattanooga residential -- $9.60

Gainesville, Fla., residential -- $11.15


Source: City of Chattanooga

"I'm hopeful some of those approaches will work, both for the environment and from the market perspective," he said.


Ms. Hundt said planners, developers and engineers will continue sitting down together to "figure out solutions" for building on slopes, handling runoff water and deciding land-use needs.

"And we'll come up with some standards that make sense," she said.

Clustering development is one solution that likely will receive more study, she said. Like parking lots that let water soak in rather than run off, cluster developments can help with stormwater, she said.

"Instead of building stores with a sea of parking and more pipes, and way down the road some apartments with another sea of parking, maybe we could look at mixing those things together," she said. "When you do that, you don't need as much paving because people walk more.

"It's just crazy to pump runoff all the way out there (to the sewage treatment plant) and spent lots of money treating it," she said. "It may be that we're already doing the most costly thing."

Staff writer Cliff Hightower contributed to this story.

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