Season: Fall
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Rain Gardens
Purpose:
Rain gardens are attractive and functional landscaped areas that are designed to capture and filter stormwater from roofs, driveways, and other hard surfaces. They collect water in bowl-shaped, vegetated areas and allow it to slowly soak into the ground. This reduces the potential for erosion and minimizes the amount of pollutants flowing from your lawn into a storm drain and eventually into our streams and lakes.
Installation:
Rain gardens can vary in size but are most effective when built to 20-30% of the drainage area. Rain gardens for single-family homes will typically range from 150 to 300 square feet, but even a smaller one will help reduce water pollution problems.
- The garden should be bowl-shaped, with the lowest point of the garden no more than 6” below the surrounding land.
- The sides should be gently sloping towards the center to prevent sudden drop-offs that could lead to erosion problems or walking hazards.
- Rain gardens are often placed in a preexisting or created depression within a lawn or in a location that receives roof runoff from a downspout.
- To avoid flooding improperly sealed foundations, build your rain garden 10’ away from existing structures and direct water into the garden with a grassy swale, French drain, gutter extension, or other device.
Rain gardens can be placed in sunny or shady regions of your lawn, but plants should be chosen accordingly, with the lowest point planted with wet tolerant species, the sides closest to the center planted with moist tolerant species, and the edges of the rain garden should be planted with sub xeric (moist to dry) or xeric (dry) tolerant plants. It is also important to check the permeability of your soil. Sandy soils only need compost added, but clay soils should be replaced with a mix (50- 60% sand, 20-30% topsoil, 20-30% compost). After the construction of the garden is complete, the entire area should be covered with a thick layer of mulch, preferably Erosion Control Mix.
Materials:
Replacement Soil mixes and Erosion Control Mix is available from local garden centers. Native plants can be purchased from your local nursery. Please see Native Plant Lists from this series for plant descriptions based on specific sun and soil conditions.
Maintenance:
Overall, once plants mature, the maintenance of a rain garden is very low. Watering is important during the first growing season, and some weeding is necessary after planting. As the garden matures, some of the perennials may need to be divided if plantings become too crowded.
Credit: Maine DEP, Portland Water District.
Part of the Conservation Practices for Homeowners Factsheet series, available at: https://www.maine.gov/dep/land/watershed/materials.html -
Rain Barrels
Managing roof runoff in your backyard.
Purpose:
Rain barrels provide an innovative way to capture rainwater from your roof, and store it for later use. Water collected from rain barrels can be used to water lawns, gardens, and indoor plants. This water would otherwise run off your roof or through downspouts and become stormwater, picking up pollutants on its way to a storm drain, stream, or lake. You can lower your water bill, conserve well water in the dry season, and reduce polluted stormwater runoff.
Installation:
A rain barrel must be placed on a level surface. If you have gutters, place the rain barrel beneath the downspout so the water flows onto the screen on top of the barrel. You may need to have your downspout cut to an appropriate height above your rain barrel. If you do not have gutters, find a location where water concentrates from your roof and place the rain barrel where it will capture this steady stream of water during rain storms.
Elevate your rain barrel by placing it on cinder blocks or a sturdy wooden frame. Raising the barrel allows the barrel to drain properly, and you to easily fit a watering can underneath the spout, or attach a hose so you can recover the rainwater you have collected. Soaker hoses can also be attached to the rain barrel to slowly release water into gardens and recharge groundwater.
Materials:
Rain barrels are available in many sizes and styles, and range in price from $80 to over $200. Contact your local hardware store, garden center, or nursery. You can also order rain barrels on-line from SkyJuice New England.
Building your own rain barrel is usually the least expensive option. Several web sites exist with material lists and clear directions. Sites are as follows:
- http://cceonondaga.org/resources/how-to-build-a-rain-barrel
- https://www.cbf.org/document-library/education-resources/rain_barrel_guide-web8bcf.pdf
Finally, you can simply use an open barrel to collect rainwater. Keep in mind that you should use the water within two weeks because the development of a mosquito from egg to adult takes 10 to 14 days.
Maintenance:
Gutters and downspouts should be clean of debris. Leaves and pine needles can clog gutters and prevent water from reaching the rain barrel. Furthermore, check the screen on the rain barrel after each storm event and remove leaves or pollen that has plugged the screen.
Freezing water can damage your barrel. Rain barrels should be drained and stored before freezing weather sets in to prevent ice damage. They can be stored outside if they are turned upside down and the faucet is covered. Be sure to put something heavy on your rain barrel so it doesn’t roll away. Rain barrels can also be stored inside a garage or other protected area.
Credit: Maine DEP, Portland Water District.
Part of the Conservation Practices for Homeowners Factsheet series, available at: https://www.maine.gov/dep/land/watershed/materials.html
