Absorbing ideas address runoff

By Heather Vogell

The Atlanta Journal-Constitution

Ideas that sounded utopian a few years ago — such as roof gardens and pavement that absorbs water — are cropping up across the country to meet new mandates for controlling rainfall after it hits the ground.

Some local governments are taking a more aggressive approach to managing storm water because of growing concerns about flooding and pollution. Driving the trend are new federal and state rules and a belief that storm water drainage problems cost taxpayers and homeowners long-term.

The new mandates have at times put developers in a crunch, adding time and money to their projects while forcing them to learn complex new approaches that continue to evolve.

But the trend shows no sign of reversing. U.S. Environmental Protection Agency officials recently began what could become a major overhaul of storm water rules that would force local governments to get significantly tougher on runoff.

Plants and rocks on roofs

Philadelphia already has. Several years ago, officials decided urban runoff had become too great a burden on the city budget and local waterways. They feared the cost of enlarging and maintaining the city’s massive storm water infrastructure would keep rising, pushing taxes higher with it.

The city set strict new rules in 2006 for anyone who disturbed 15,000 square feet of land, which is roughly the size of a chain drugstore. The goal: To keep most water on site, instead of allowing it to run off buildings and parking lots into city gutters and catch basins.

The first inch of rain became the developers’ problem. They could use grassy areas, plants on the roof, porous pavement or other means to make it stay put. Excess rain had to be detained, cleaned and released, very slowly.

Developers complained loudly about the cost. The city struggled to implement its new rules. But three years later, water department Planning and Research Director Christopher Crockett said the change is “one of the best things we’ve done in the city.”

“It’s just like putting money in your savings account,” he said. “That’s infrastructure we don’t have to maintain and operate.”

Today, Philadelphia has the largest area covered by so-called green roofs, which use plants and media such as stacked rocks to contain runoff, of any city nationwide except Chicago, he said. The city expects its seven acres of green roofs to more than double in the next few years. Credits on storm water bills encourage land owners to make changes such as adding porous surface to existing developments.

“There’s no silver bullet,” Crockett said. “Once you’ve gotten yourself into that hole you can only dig yourself out one shovel at a time.”

In Florida, porous pavement is popular as a way for builders to turn developed land such as parking lots into a drainage feature, said Marty Wanielista, a storm water expert and professor emeritus at the University of Central Florida.

The state has long been concerned with minimizing flooding, Wanielista said, and its pro-active measures have eased the problem. Florida’s watershed management districts can and do overrule local land-use decisions if they are harmful to the watershed. Georgia has no such process.

Local regulations in Florida vary in strictness, depending largely on how bad a flooding problem the area has, he said. “It depends on the will of the people and the politicians how well they want to enforce these things,” he said.

The problem with clay

Georgia’s hard-packed clay soil makes porous pavement or driveways pointless, unless layers of rocks are installed below the pavement to help water drain, said Steve Haubner, a water resources engineer with the planning agency the Atlanta Regional Commission.

In general, the state has been slower to adopt effective anti-flooding measures.

That appears to be changing.

At the state’s request, the ARC published a storm water manual in 2001 offering local governments their first formal guide on how to control runoff. It also recommends rainfall be absorbed or detained instead of being dumped.

Over the past decade, Haubner said, he has seen a change in how subdivisions are built in the metro area, with less mass grading and more trees and natural areas preserved. Such an approach often works best here, he said, because grass, trees and plants are good filters for runoff.

Yet, while the region has made progress in controlling storm water through land-use planning, local governments still have work to do, he said.

“Even though our communities have programs, I don’t think they’re anywhere near as effective as they need to be,” he said. “Addressing the problems when we develop rather than having to go back and address them later is just way more cost efficient.”

Michael E. Paris, president and CEO of the Georgia developers’ association the Council for Quality Growth, said that his group has supported most measures passed by metro governments to decrease flooding.

“The council has generally believed that getting out front in those issues is better than catching up in the end,” he said.

But, he said, tighter regulations could squeeze developers and builders and make it harder to recruit new companies to bring jobs and build new facilities. State and local officials are usually easy to work with, he added, but federal mandates can be inflexible and harmful to the industry.

In the end, homeowners bear the cost of such mandates, he said.

“Every dollar that is spent is a dollar the homeowner has to pay for,” he said. “It’s not as if the money is ending up in the builder’s pocket.”

Storm water utilities

In Georgia, local officials say they are mostly focused on finding money to maintain the storm water elements they have. Some are more successful than others.

Those that created storm water “utilities” in recent years said the agencies are instrumental to maintaining infrastructure and preventing flooding. Utilities charge property owners a fee based on the square footage of impervious, or nonabsorbent, surface, such as roofs, driveways and parking lots. The revenue provides a steady source of cash for repairs.

In Fayetteville, south of Atlanta, a storm water utility provided $2 million for upgrades to nine culverts and a dam. Public Services Director Don Easterbrook said the work helped keep water out of houses during the September storms. No serious flooding of homes or businesses was reported. “And there almost certainly would have been otherwise,” he said.

Gwinnett started a storm water utility in 2006, largely because the county realized its rapid, sustained growth had left behind massive storm water infrastructure to maintain, said Steve Leo, director of the county’s storm water management division. Older, corrugated metal pipes from the 1980s were likely to start failing, for example.

“We saw the curve,” he said. “You have two waves. You have the wave of development and you have the wave of maintenance and development that was going to come later.”

Because the county’s infrastructure is so sprawling — it has enough storm drain lines to stretch from Gwinnett to Albuquerque, N.M., for instance — it estimates the risk of failure for storm water elements and prioritizes fixes, instead of inspecting each structure regularly.

The city of Griffin, south of the metro area, created the state’s first storm water utility in 1998.

Years of flooding prompted officials there to use the revenue to perform complex modeling to better understand where floods had the greatest impact. That led to culvert repairs to end flooding on key roads, said Public Works and Utilities Director Brant Keller.

The city also posted detailed flood maps it developed online and notified property owners who appeared most at risk. The city has banned building in the flood plain for years.

Todd Edwards, associate legislative director for the Association County Commissioners of Georgia, said local officials are gaining a greater understanding of the link between development, flooding and pollution. They are doing what they can with limited money.

“There’s definitely a better awareness,” Edwards said. “We could have done things better in the past, but we’re coming together for a better future.”

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How we got the story

For this series, the Atlanta Journal-Constitution interviewed more than 60 homeowners, local officials, engineers, environmental officials and policy experts and reviewed state storm water permits and annual reports filed by 15 metro area cities and counties. The newspaper performed its own analysis of the effect of development on streams and creeks in metro Atlanta, using monitoring data provided by the U.S. Geological Survey.