Good for your garden and the lakes

Rain barrels can help with watering plants and preventing stormwater runoff

kids with rain barrel
Micah and Kalah Manneberg-Tompkins help garden outside their ECCO home with water their father, David Tompkins, collected in a rain barrel. Photo by Sheila Regan

As garden season enters full swing, you may want to consider catching the rain barrel trend.

Rain barrels help conserve water and prevent surface runoff. They catch rain that flows from the roof of your home, which might otherwise run into the city’s water system. Rain barrels are good for the environment and may actually save you a bit of money on your water bill, especially if you do a lot of watering in your lawn or garden.

David Tompkins, an ECCO resident who is part of the neighborhood’s Green Team, got his three rain barrels soon after moving into his house about a decade ago. There was a program developed in partnership with ECCO and the Minnehaha Watershed District that subsidized the cost of the barrels at the time, he said.

At first, Tompkins hooked up the barrels to an irrigation system, but that proved too complicated. Now, he said, he does it “old school”: From a hose connected to the barrel, he fills up a watering can. (His two kids, Kaiah and Micah, sometimes help with the task.)

Tompkins said he imagines he’s saving money but hasn’t kept close enough track to say for sure. The main reason he set up the rain barrels was for environmental reasons. “It captures rain water from going into the drain and into the city’s lakes,” he said. “We also wanted to use less water.”

Tompkins also fights water runoff with a rain garden and with permeable pavers for his patio, which means water seeps into the earth rather than a concrete surface. Water runoff “picks up the oil or whatever is on the concrete on the roads and it all washes into the storm drain and into the lake,” Tompkins said. “All those bad things from cars go into Bde Maka Ska. It’s better to keep your stormwater on your own property rather than shoot it out into the system.”

David Tompkins in the rain garden
David Tompkins in the rain garden outside his ECCO home. Photo by Sheila Regan

Rain barrels are popping up in lots of homes around Southwest Minneapolis. Nathan Campeau, a water resources engineer who lives in the ECCO neighborhood and designs rainwater collection for a living, said he’s noticed barrels becoming more common.

A 2018 report prepared by the Minnesota Department of Health called water reuse “an increasingly important part of managing Minnesota’s water resources” as a rising population, a growing industrial sector and climate change place added demand on the state’s water supplies.

Emily Ruiz, who lives in Seward, installed rain barrels partly out of a desire to mitigate flooding. “We were trying to keep water from the basement,” she said. “We still get flooding, but it’s better than it was before.”

Since there’s been so much rain this spring, Ruiz said she’s happy her water barrel has an overflow system. “Right now, we have more than we need,” she said. “But I do use it all in the drier times … It’s shocking how quickly they fill up.”

Anita Anderson, the lead engineer in MDH’s drinking water protection section, said that reducing impervious surfaces around your home and putting in native plants can “minimize the need for irrigation” to the point that rain barrels provide a sufficient outdoor water supply.

Joel Sass, who lives in the Field neighborhood, had two 60-gallon barrels for about 10 years. He also found that the rain barrels prevented water from soaking into his home’s foundation. Plus, he said, “it helps us stock reserves of water to use when we’re rainless.”

These days, you can pick up rain barrels at many garden or home improvement stores, which sell the attachments you need to connect them to your gutter downspout. Some varieties have the ability to connect to a hose as well, though you’ll need to have your rain barrel up on a platform if you want gravity to work properly.

Patti Paulson's rain barrels
These two 55-gallon metal drums, once used to store and ship honey, have been repurposed into rain barrels. Submitted photo

You can also repurpose other types of barrels to catch rainwater. Patti Paulson, who lives in Robbinsdale, uses two 55-gallon metal drums once used to store and ship honey. She has added screens to prevent mosquitos from laying eggs and attached bricks to keep the screen from blowing off. Paulson said she’s heard of folks putting goldfish in their rain barrels to eat the mosquito larvae. “It works, but that just seems inhumane to me,” she said.

In Minneapolis, there are some larger-scale rain barrel systems that go beyond using rainwater for watering plants. Westminster Presbyterian, for example, collects rainwater for toilets and urinals, as well as for irrigation. The light rail station at Target Field has a cistern that uses water to cool the ash from the Hennepin Energy Recovery Center, the county’s garbage incinerator.

Scott Eggen, a plumbing inspector for the city, said it’s rare for homeowners to set up a rainwater collection system to be used indoors. That may be in part because you need approval from the commissioner in order to set up such a system, he said.

Common types of water reuse projects in Minnesota
Common types of water reuse projects in Minnesota (estimated). Courtesy the Minnesota Department of Health

Chapter 17 of the city’s plumbing code allows for water collected from a roof to be used for water closets, urinals, floor drains and various industrial uses, but only after a plumbing contractor does certain tests to make sure that it has absolutely no connection to the potable water supply.

Bill Smith, the city’s manager of construction inspection, said both state and city regulations are clear that reused water must not be used for human consumption. “There have been applications in the past,” he said. “They’ve tried to use it for toilet water and that’s about it.” Even bathing and doing the dishes are off limits, he said.

But for gardens, “there’s no concern whatsoever,” Smith said. “It’s no different than the actual rain that comes in.”

It turns out that while stormwater has pollutants that are very bad for human consumption, they are very helpful for plants.

Your lawn and garden will love the extra phosphorus and nitrogen you capture in your rain barrel, both of which are used in fertilizers. It’s also helpful if you have orchids, which require water without fluoride. But, to be on the safe side, you may want to avoid watering produce or anything you might eat with your roof water.