The Lincoln Public Works and Utilities Department wants to build 20 rain gardens in the watershed above Holmes Lake as a demonstration project.
ALGIS J. LAUKAITIS / Lincoln Journal Star | Posted: Monday, June 25, 2007 7:00 pm
Flower gardens.
Veggie gardens.
Herb gardens.
Butterfly gardens.
Rain gardens.
Huh?
That’s right. Rain gardens.
The Lincoln Public Works and Utilities Department wants to build 20 rain gardens in the watershed above Holmes Lake as a demonstration project. It also wants to inform the public about what can be done on a small scale to maintain and improve water quality.
A rain garden is a small garden planted in a depression with native shrubs, perennials and flowers. It is designed to collect water that runs off roofs, driveways, patios or lawns, and release it slowly into the soil.
Ed Kouma, an engineer with the department’s water management division, said the idea is to trap chemicals and sediments in the rain garden before they enter the lake and harm aquatic life.
The city, along with its state and federal partners, recently spent $5.5 million on an extensive renovation of the lake and they’ve come up with a program that could help maintain or improve its water quality in future years.
“With all of the work done on Holmes Lake we’re definitely interested in improving the quality of the water running into the lake so we don’t have any problems,” Kouma said.
Rain gardens are among three pollution-prevention actions that the department is exploring. The others are giving away rain barrels and non-phosphorus lawn fertilizer.
Experts say rain gardens are effective in removing up to 90 percent of the chemicals and up to 80 percent of the sediment from rainwater runoff.
Kouma said the city is interested in building 20 rain gardens in the watershed, all on a voluntary basis. Rain gardens not only improve water quality by filtering out pollutants but the native plants can be an attractive feature and also benefit insects, birds and other wildlife.
“Water is intended to infiltrate out of a garden within a 48-hour period,” Kouma said. “This is not designed to be a wetland, bog or pond. It’s nothing like that. It’s intended to be dry most of the time … If there is no rain it will have to be watered.”
Kouma said the city will pay for 90 percent of the cost of a rain garden; the homeowner 10 percent. The work will be done by a landscape contractor hired by the city. Each rain garden will be sized to the amount of runoff on the property.
Kouma said the city also will be distributing free bags of non-phosphorous lawn fertilizer and rain barrels, as part of a Holmes Lake Watershed Pollutant Reduction Project. Fertilizers containing phosphorous promote algae growth in the lake.
While some lawns may need fertilizer containing phosphorous to promote new growth, Kouma said, there is enough phosphorous already in the soils of the watershed, so adding more doesn’t benefit a lawn. Instead, it only offers opportunities for the phosphorous to wash off and flow into waterways.
One thousand free bags of fertilizer will be distributed. Homeowners who live in the watershed above the lake will receive a coupon which can be redeemed for the free fertilizer.
Rain barrels are an old-fashioned idea for saving water for irrigation and other purposes. But they also help trap some of the water and sediment that would end up as runoff. Twenty rain barrels, each holding about 55 gallons of water, will be distributed on a first-come basis, Kouma said.
“They are not for potable water but rainwater is good quality water,” he said.
Each rain barrel will be fitted with a spigot so homeowners can easily get to the water and use it on their flower beds or gardens. Kouma said they’ve gotten a few calls already for the rain barrels.
The city is funding the water quality program through a $254,680 grant from the Nebraska Department of Environmental Quality. The money came from the U.S. Environmental Protection Agency under a federal water quality program.
“It was given to us to give out specifically for projects involving non-point source pollution,” said DEQ spokesman Rich Webster. Non-point source pollution includes rainwater runoff.
The state agency is also providing advice and assistance to the city, which is contributing $96,100. The Lower Platte South Natural Resources District is also helping out with $60,000 and $12,348 is coming from the University of Nebraska-Lincoln and private donations.
Rain gardens, which are popular on the East Coast, are relatively new in Lincoln. Kouma said he is not aware of any that have been built in yards but the city has installed a large one in a parking lot at 63rd Street and Platte Avenue in Havelock and is working on another one next to a parking lot near 27th and F streets.
Reach Algis J. Laukaitis at (402) 473-7243 or alaukaitis@journalstar.com.