Cities promote gardens to manage stormwater runoff

By Haley Walker

When it was time to repave the streets, officials in Maplewood, Minn. decided it was also time for a different way to manage stormwater.

More than a decade ago, city officials began creating rain gardens whenever they rebuilt the streets. The shallow basins are dug into the landscape to collect water after it rains. The areas are planted to filter the water, which often contains fertilizers, pesticides, oil and other pollutants.

“Every 20 or 30 years, there is a major opportunity to renovate stormwater and septic in cities,” said Virginia Gaynor, Maplewood’s natural resources coordinator. “Our city engineer just wanted to figure out how to do things better.”

Untreated stormwater that runs into sewers contaminates rivers, lakes and streams.  Maplewood officials say rain gardens can reduce this runoff by 80 percent each year.

Too much water entering sewers can also damage the shape and construction of waterways.“All that water drops into the sewer and gets delivered to a river all at the same time,” said Bob Newport, a storm water specialist with the Environmental Protection Agency in Chicago.  “That big surge of water at the same time erodes the channel and base of the river.”

For the past ten years, Maplewood residents have been given the option of having a free rain garden on their property when the city rebuilt their streets. They choose from a variety of designs. The city builds them and supplies the plants.

Today, more than 500 gardens have been planted in Maplewood, including 30 on public land.

It isn’t the only city in the Great Lakes region featuring these projects.

The West Michigan Environmental Action Council started a rain garden program in 2001 and has helped create 40 gardens in the Grand Rapids area. “It’s already a trend, because when we started the program no one had heard about it and now it’s a household name,” said Patricia Pennell, program manager of rain gardens and low impact development at the West Michigan Environmental Action Council. “All over Michigan, municipalities, engineering firms, and individuals are doing them.”

The Southeastern Oakland County Water Authority in Royal Oak, Mich. also teaches people to create the gardens. Approximately 60 people attended a recent public workshop.

The county water authority gives guidelines on choosing a site, size, soil and plants. For instance, native flowers and shrubs are important because they are already adapted to the landscape and are more likely to contribute to the natural ecosystem. They also require less water and fertilizer.

“There is an art to designing the rain gardens,” said Lillian Dean, coordinator of Oakland County’s water authority’s healthy lawn and garden program. “The best vision for these is one of slow and steady implementation where the homeowners know enough about the garden to maintain it.”

According to Newport, creating rain gardens is a growing trend. Cities with rain garden programs might also be getting a jump-start on new storm water regulations, he said.

The Environmental Protection Agency recently announced plans to create more comprehensive regulations for its stormwater program.

One of the agency’s goals  is  more consistent rules for stormwater discharge from developments and redevelopment, like the street reconstruction projects.  The plan would also expand the areas subject to federal regulation.

The new regulations will be developed over the next two years, Newport said.

“We would never say you have to put a rain garden in your front yard, but what we could say is that we need to work on how much stormwater runs off,” he said. “We do need to find a new way to absorb the water into the ground, and rain gardens are really the solution that works the best in many cases.”

For some however, environmentally friendly changes came before any proposed regulations.

Anne and Peter Bray from Birmingham, Mich. began making their lawn more sustainable more than a decade ago. Today, they have removed all traditional lawn grass and transformed their entire property into a working rain garden.

“Looking ahead, lawns will become more and more unsustainable and expensive to maintain,” Anne Bray said. “As a species, we have become almost totally disconnected from the planet and have forgotten that we are completely dependent upon clean water, the health of the soil and sunlight for survival…Rain gardens are a good way to reverse this disconnect.”

Editors note: This is part of a series of stories about Great Lakes sewer system issues.