By Greg Ellison
(June 18, 2020) Installing rain barrels or planting backyard rain gardens to aid stormwater runoff and lessen waterway pollutants or toxins was the message delivered during a virtual seminar sponsored by the Ocean Pines Association last Tuesday.
University of Maryland Sea Grant Extension Watershed Restoration Specialist Jennifer Dindinger, who conducted the Facebook live event on June 9, reviewed details about constructing rain barrels or rain gardens and the importance of addressing excessive stormwater runoff.
“The reason we care about stormwater is the water quality in the coastal bays is declining,” she said. “Our storm drain systems do not go through wastewater treatment.”
Dindinger said stormwater runoff is a principal way pollutants — trash, toxins, bacteria and excessive nutrients — enter streams and rivers.
“Temperature can also be a pollutant if the temperature of your creeks or stream beds needs to stay cool in order to handle fish populations,” she said. “When water hits hot pavement in the summer, it can absorb heat which can be transferred.”
One solution homeowners can consider is making or purchasing a rain barrel, which Dindinger said is a useful conservation tool that can reduce potable water usage.
“Rain barrels are not going to stop all the drops of water that hit your roof from becoming stormwater runoff, but they are helping to collect the first flush of stormwater runoff from your roof,” she said.
Initial rainfall reaching the ground tends to pull oils, chemicals or refuse off roadways to produce a slick toxic blend.
“I like to call rain barrels the gateway drug to stormwater management because they’re a pretty easy, discrete thing to start with rather than re-landscaping your whole property to make a massive rain garden,” she said.
Dindinger said there are two types of rain barrel designs, both of which can be produced at home or purchased at most hardware retailers.
“Rain barrels are much easier to find than they were 10 to 15 years ago,” she said.
In addition to a barrel option, rain stations can also be deployed to the same end.
The latter involves cutting downspouts and connecting them to mesh tops to filter rainwater and remove debris from gutters.
Dindinger said the barrel concept differs slightly.
“You don’t cut the entire downspout but cut a hole and there’s a converter that brings the water into the barrel,” she said.
Either version includes a spigot and or a drain at the bottom.
“When the barrel is full, the water is allowed to continue coming down the downspout like normal,” she said. ‘This has a closed lid, which can help prevent mosquitos entering and breeding in barrel water.”
Rain barrels require elevation to allow gravity to move water through the spigot, with stands needing to be level and sufficiently strong for weight support.
“Rain barrels can hold 40-50 or more gallons of water,” she said. “They can get super heavy and might accidently tip over.”
Other considerations include locating an accessible area for barrel placement.
Dindinger said ideally barrels should be emptied regularly with spigots closed to assure the first flush of rainwater is retained.
If there are no obvious yard areas to direct the collected precipitation, it can also be slowly released into the immediate area.
“If you let it trickle out then it will slowly infiltrate … and the bacteria in the ground can act on any of the excess nutrients,” she said. “It also helps with ground water recharge.”
During the offseason it is advisable to fully drain and rinse barrels, which should be stored inside and upside down.
“It does not winter well as water could freeze and crack the barrel,” she said.
In lieu of using a barrel to collect stormwater runoff, rain gardens can also serve the same purpose.
“The rain garden … is a shallow depression in the ground,” she said. “It’s almost like a pond that’s mostly been filled back in with soil and plants specially selected to get wet more often.”
Rain gardens, which do not retain all the stormwater, are intended for an average total rainfall of under two inches.
“In the case of bigger storms, rain gardens need to be able to overflow,” she said.
Dindinger advised using soil mixes with sufficient porous space.
“You want the water to be able to trickle down and sit for the plants,” she said.
Water flowing off impervious surfaces, such as roofs or driveways, can be channeled to the rain garden through a swale or pipe across yard landscaping.
Dindinger said to start the process property owners should map their yards to account for structures, trees or utility boxes.
“When it rains, get out there and see where the water is going and … where it’s coming from,” she said. “The point is to allow that water to infiltrate and not to let it just sit and allow for mosquitos to grow.”
Dindinger also mentioned the importance of contacting Miss Utility or a comparable private firm before installing rain gardens.
“We definitely don’t want you getting hurt because the utilities haven’t been marked in your yard and then you start digging,” she said.
To view the presentation, visit www.facebook.com/jennifer.dindinger/videos/10157598830204891.