Fri September 6, 2013
City's Rain Gardens Save Environment, And More
August 27, the Aurora City Council approved a contract to build a series of rain gardens on the city’s east side. The city is trying to meet federal and state clean water requirements, and believes rain gardens offer a good alternative to traditional methods of water management. As it turns out, that’s not all they do.
On a sunny summer day in downtown Aurora, Eric Schoeny, Drainage and Underground Coordinator for the City of Aurora, shows off some of the rain gardens at an intersection at the west end of the newly rebuilt Downer Place bridge over the Fox River. The beds jutting out from the corners of the intersection into the street look pretty but, as Schoeny points out, they’re not just for looks.
“Does a great job with water quality. But also from a traffic perspective. Cars slow down when they see this constricted roadway.”
Schoeny points to the inlets along the curbs. They drain not into an underground pipe but into the gardens, where any water that collects seeps through several feet of rock, sand and gravel into the subsoil. As that happens, Schoeny says, the subsoil underneath the city is itself a mix of sand and gravel, and acts as natural filter for the runoff before it gets to the river.
For decades, the main issue for municipalities dealing with wastewater and runoff from rain was how to get it away from people’s homes. Schoeny says Aurora is one of many cities across the country that, over one hundred years ago, built combined sewer and drain systems. They generally worked well but had one big drawback.
“When it rains, that water level in the sewer builds up to the point that it is above the floor of the basement and they get raw sewage in their basements.”
In recent decades, the city began separating the sewers and street drains. Schoeny says that helped alleviate the problem of sewer backups. But it also meant not everything was going through treatment, with consequences for the environment.
“That resulted in a new outfall that just transported the storm water to the river. Well, we sampled that storm water, and we found really some interesting things in the storm water.”
Like fecal coliform bacteria, along with phosphorus and other pollutants. Federal and state environmental protection agencies are aware of this, too, and have issued mandates to cities and towns up and down the river to clean up their outflow. Schoeny says doing that the traditional way -- digging up streets and running miles of additional lines to the treatment plant -- is incredibly expensive. But, he says, they had an example of an alternative: a rain garden built several years before along a street on the edge of McCarty Park near downtown Aurora.
“We had planned on constructing about 700 feet of storm sewer to get to that park to pick up some street inlets. Well this rain garden did such a good job we didn’t have to do that. And the storm sewer component would have been about 170, 000 dollars. McCarty Park cost about 67, 000.”
Not only that, Schoeny says, it removes pollutants from the river, and it adds to the beauty of the park.
The cost savings don’t stop there. Tom Muth is District Manager for Fox Metro Water Reclamation District.
“We represent five communities and parts of two others. That’s about a 300 thousand population base. During a normal day we treat in the low thirties -- thirty million gallons a day.”
Fox Metro’s 65-acre facility -- with its series of filters, digesters, aerators and other equipment -- transforms the dark, smelly liquid that comes to the plant into crystal clear water that, Muth says, is cleaner than the river it flows into.
Muth says, whenever you can use natural means to achieve that, you’re going to be better off. He says the cost of adding new treatment equipment can run to hundreds of millions of dollars, so even a little help from rain gardens can lead to significant savings. Muth says they can also help with future costs.
“Mechanical functions can break down. Humans beings can make errors. The upkeep of it. The personnel it takes to maintain it. That’s in perpetuity. (A) rain garden may need a little watering now and then, maybe a little de-weeding or something like that, but that’s more natural.”
Schoeny says once Aurora’s administration saw the benefits of rain gardens, it got strongly behind a 1.7 million dollar plan to create rain gardens at 28 intersections throughout the city. The city was able cover most of the cost of the project with a 1.4 million dollar grant from a state program set up to encourage green initiatives
Charlie Zine is Conservation Chairman for the Fox Valley Group of the Sierra Club. The group is working with the city on education and outreach to the public about the project. Zine has long been involved with groups that advocate for better water quality. He has a personal stake, as well.
“I love the river because I’m a recreational kayaker. When we go out and play in the river, we actually touch the water.”
That’s considered a primary recreational use of the river, and that triggers higher standards for water quality. Increased recreation on the river is one reason for the EPA mandate.
Zine says as a resident and a taxpayer, he likes the fact that an idea that he would endorse on philosophical grounds won’t hurt his pocketbook. He wants other residents to take ownership of the rain gardens. And he’s happy to spread the word.
“We’ve taken water for granted. We’ve always had plentiful water, OK, which is why we didn’t worry about polluting it. It always went downstream, and it was somebody else’s problem. But somebody else lives downstream, and we live downstream from somebody else. So the problem is universal.”
Rain gardens will be built on the corners at seventeen intersections on the city’s east side in a bump-out design similar to those on Downer Place. Schoeny says residents have embraced the idea, but not necessarily because of the environmental impact, or even the cost savings.
“You know, if you asked them, they’d say yeah we’d like clean water, but what they really liked these was more because of the traffic calming benefits.”
Schoeny says that’s another nice part of this. A conventional project, he says, does one thing -- move water -- and the results are buried out of sight, out of mind, unless they fail. But, Schoeny says, the rain gardens, as they do their several jobs, will be there for all to see and enjoy for years to come.
Work is scheduled to begin soon on the east side gardens. Schoeny says a contract for rain gardens at eleven intersections on the city’s west side will be let out for bid in the spring. The goal is to have all the gardens completed by fall of 2014.