Farm manager Patrick Crouch had plenty of motivation for investing in a rainwater catchment system in Earthworks Urban Farm at the Capuchin Soup Kitchen on Detroit's East Side.
Crouch says rainwater is better for plants than treated municipal water. Also, a catchment system can prevent runoff from flooding the hoop house (a passive solar greenhouse used for producing food year-round) and overflowing into municipal gutters. And of course, there's the cost of city water for a structure that needs almost constant irrigation, as well as the potential of securing credits for green infrastructure under the Detroit Water and Sewerage Department's new storm-water rules.
"So looking at all those factors together," Crouch says, "it seemed like the most cost-effective thing
—even though it wasn't cheap up front."
Much has been made of the vast amounts of open space potentially available for farming in a city like Detroit. But this land is often lacking in water infrastructure. Water lines and sewerage costs can be prohibitively expensive. Fortunately, green infrastructure has the potential to make these spaces productive and profitable.
Patrick Crouch at Earthworks Urban Farms
The Earthworks system consists of three tanks
—two below ground and one elevated above—that receive rainwater from the gutters on the side of the hoop-house. The lower tanks take the water directly and a solar-powered pump slowly moves it into the elevated tank to give it the necessary pressure to force it through the drip lines running back into the hoop-house.
Crouch estimates that the system costs about $14,000. A meter on the line shows the system has collected about 36,000 gallons of water in the last year. That might not offset the expense of installation immediately, but the cost of putting in a new line and meter at the site was estimated to be around $8,000. The combination of savings on buying water, not installing the meter and line and taking advantage of credits on city stormwater drainage fees shortly could easily put this project in the black in a couple of years.
The project was made possible with a grant from the Erb Family Foundation, who sponsored the system at Earthworks. The support allows Crouch to do things that others may not be able to organize or afford. By analyzing different methods and troubleshooting on the front end, they can pass on information to other growers that could save them time and money.
Another Erb Foundation grantee, the Detroit Black Community Food Security Network (DBCFSN) has installed a different type of system on their property at D-Town Farm in Rouge Park. Using the site's slope toward the Rouge River, they decided to install a retention pond that collects water in an area of the farm prone to seasonal flooding. From there, a solar-powered pump moves it uphill to a raised cistern where it can then be used for drip irrigation.
"You have to alter the system to fit the specifics that the grower's facing," Malik Yakini, DBCFN's chairman explains. But with innovations come unique problems.
Yakini says that they installed a solar-powered bubbler in the pond to prevent mosquitoes from laying eggs. They also had to secure it with a fence to prevent children from endangering themselves.
Malik Yakini at DTown Farms
It's hard to foresee all the potential difficulties of creating these water catchment systems, technical or otherwise. Crouch had planned on putting in a platform with rainwater tanks to collect water off his roof and give it enough pressure to irrigate his growing space. However, he realized that by building such a structure he'd essentially be creating a ladder to his second story window and decided against it. Instead, he's going to put in a ground level tank and use an electric pump.
Trials like the ones at D-Town Farm and Earthworks are creating a base of knowledge that others can build on when executing a project. They also open up possibilities for outreach and multiple uses.
"We give a lot of tours at our farm," Yakini says. "So that's now definitely one of the highlights of the tour. And it gives us an opportunity to engage people in a discussion about water and the value of water and being conservative with it and implementing practices which help to conserve."
Where all of this could lead in the future is still anyone's guess. Landscape architect Jeff Klein who helped design both the system at D-Town and the one at Earthworks thinks that the future lies in finding ways to stack complementary systems and make them aesthetically pleasing.
"I haven't seen anyone take it to the next level," he says. "Like could a rain garden be a cut flower garden? That would start to get real interesting."
As Yakini points out, organically managed farms already do a lot for the city by sequestering rainwater.
"Having healthy organic soil which is permeable helps to retain water," he says. "Those practices generally, even without the retention pond, help to divert water from the stormwater system."
Adding water catchment systems to the mix could be one more way that urban agriculture can enhance the city landscape beyond the production of food and the environmental benefits that go along with it
—both as an educational tool to show residents what water catchment can do and as functional and beautiful design.
This story is part of a series on measuring on the role of green infrastructure projects in Detroit's redevelopment. Support for this series is provided by the Erb Family Foundation to Greening of Detroit, Model D, and The Nature Conservancy. Read more articles from the series here.
All photos by Nick Hagen.