The following is an excerpt from City Parks, Clean Water, a report by The Trust for Public Land’s Center for City Park Excellence that examines the role of urban parks in managing stormwater. This is the second installment in a series of 19 posts.
One of the nation’s most celebrated marriages of recreation and green infrastructure,
Atlanta’s Historic Fourth Ward Park is a $23-million triumph of engineering over flooding and landscape design over stop-gap asphalt.
The central stream of the old Fourth Ward, Clear Creek, was less known for clarity than for flooding. This was particularly true around the huge Sears warehouse (once the largest brick building in the Southeast), the basement of which was wet ever since it was constructed in 1926. After Sears vacated in 1989, the situation got worse: Atlanta bought it for an annex to City Hall, so the documents mildewing in the lower levels were public records.
At about the same time, as part of a legal settlement with the U.S. Environmental Protection Agency, Atlanta agreed to spend millions of dollars to end pollution of the Chattahoochee River, which entailed doing something about the storm sewer along Clear Creek. The initial concept was to dig a gigantic underground tunnel and channel stormwater to a processing plant before sending the cleaned residue to the river, but the cost was projected at $40 million. Some years earlier an engineer-economist named Bill Eisenhauer had come up with an alternative approach. Calculating the amount of stormwater needed to be held back, the amount of space that would be required, and the cost of assembling land in various communities, he hit upon the idea of a storage pond in a ramshackle industrial strip just upstream from the Sears warehouse. Eisenhauer had good organizing skills — he had earlier successfully led the opposition to building a sewage treatment plant in Piedmont Park — but his idea didn’t gain traction until local architect Markham Smith heard about it.
“From the mayor on down,” said Smith, “the city had already committed to the massive pipe, and I thought promoting an alternative would be insurmountable. But there was one glimmer of hope. Most of the underutilized land was held by major property owners who might be able to gain from improvements in the area. The neighborhood had undergone a terrible downward transition since the 1960s — it was blighted. I said to Bill, ‘This needs to be not a holding pond but something much bigger — greenspace for community redevelopment with a water conservation element.’ It had to work for both people and nature.”
It was a breakthrough, but even that might not have been enough if it weren’t for other stars aligning in 2004. For one thing, the city owned one of the parcels. For another, the area was crossed by abandoned railroad tracks — just at the moment that the new concept of a “Beltline” of light-rail transit, bike trails, parks and housing was gaining attention. Third, the Jamestown Construction Co. had purchased the Sears building for a huge redevelopment project that hinged partly on solving the flooding problem in the basement. Lastly, the real estate market was extremely hot and properties in the area were finally desirable.
“Everyone liked the park in concept but no one wanted to take the lead,” said Smith. “We were willing to lead, but we couldn’t because we didn’t have control over any property. We finally found a little milk storage warehouse right in the epicenter of the drainage, got an option on it, and went to The Trust for Public Land. TPL liked the concept and took an enormous risk by buying the property. It turned out to be the first purchase of the entire Atlanta BeltLine. We then started working three-way deals with the city and with developers — they would get a rezoning and part of a property for housing if they would leave TPL the rest for the park. It was done on a wing and a prayer. We were showing them a design for a park that didn’t exist, that hadn’t been approved by the city, and for which there was no money — and they were enthusiastic.”
By 2008, 17 acres had been assembled. Phase I of the park was the 5-acre pond, set deeply into a bowl below the water table. Phase II was the 12 surrounding acres of landscaped walkways, bridges, observation points, walls, splashpad, and playground. Phase III was a skatepark and a grassy field. Starting in January, 2009, the effort was turned over to Kevin Burke, senior landscape architect for Atlanta BeltLine, Inc. “From the water perspective, the park is actually overdesigned,” said Burke. “It can handle a 500-year flood. We’re in the position where the city has even allowed two additional developers to tie their runoff into the pond.”
The park does not infiltrate or clean the water flowing in from the 300-acre subdrainage; it simply gets detained. With a gradual and manageable outflow over a 24-to-36-hour period after a storm, this consistent volume then travels steadily to the city’s sewage treatment plant. (Ironically, since the park is built over a natural spring, it happens to generate water even without a storm; the combination of the spring plus artificial fountains and an ornamental stream keeps the pond aerated and circulating without an algae or a mosquito problem.) The pond also provides water for irrigation so that potable water is not wasted on plants.
As for clean-up after any storm that raises the level of the pond, a city parks department crew removes debris, cleans out the drainage basins, and power-washes any sediment away. However, the park definitely requires attention.
“Fourth Ward Park is very high maintenance,” said Esther Stokes, chair of the maintenance committee of the Historic Fourth Ward Park Conservancy. “Part of its charm comes from the many shrub species and the many different grass species, but it’s hard for the staff to deal with all those factors. The park department is underfunded, which is why the conservancy partners with them. We recently hired a company to do deep core aeration and fertilization. We also work with different companies to each adopt one of the park’s seven zones.”
Doug Voss, director of parks at the Atlanta Department of Parks, Recreation and Cultural Affairs, explained some of the details. “Rather than removing invasives by hand, we use pine straw as mulch — a lot of pine straw, 1,000 bales worth. We get volunteers to put it down at an event called ‘Pinestrawpalooza.’ It works well, but when the water gets high the bowl fills up, and straw mulch drifts everywhere. That’s when we have to clear out all the drains and catch basins.”
Despite the challenges, the park is well worth it.
“It’s a prodigious economic engine,” the Beltline’s Burke concluded. “The Jamestown Company didn’t decide to go ahead with its Ponce City Market project until the pond had been built and proven. Once that happened, they committed $250 million. That was followed, soon thereafter, with another $150 million of new development.”