Efforts to encourage water stewardship within the community continue to increase as populations rise and few alternative water sources exist for area residents. Over the last few years a lot of interests have emphasized the practice of rainwater harvesting as an important water conservation practice. Rainwater harvesting is simply the process of capturing and storing rainwater for later use. And while many of us immediately think of a rain barrel when rain water harvesting is discussed, a well-designed landscape can also allow for rainwater harvesting.
This type of landscape is known as a raingarden. Raingardens capture rainfall, beatify the community, improve curb appeal and home values, and reduce runoff that can lead to nonpoint source pollution. Raingardens are either bowl-shaped or surrounded by berms to retain water. Raingardens are not ponds they are typically planted with native or adapted vegetation that tolerates both waterlogging and drought. A list of plants ideal for these types of gardens can be found at: http://bit.ly/2nKlFx7.
A raingarden collects rainwater runoff from a catchment area. The size of a rain garden varies depending on the size of the catchment area. The catchment area is the impervious surfaces that collect rainwater that falls such as parking lots, driveways, sidewalks, patios, and roof of the home where water is not absorbed into the soil but instead runs off. A 1,500 square-foot home has an impervious roof that will shed around 465 gallons of water from a ½” of rain.
Excess rainfall runoff has properties that can harm the environment. Urban runoff also carries many pollutants into streams and rivers. Water flowing over roads and parking lots picks up oils, heavy metals and other chemicals that leak from vehicles. Water flowing over yards picks up excess fertilizers, chemicals, animal wastes and grass clippings. Rainwater is also often heated by pavement and roofs that it falls on and can raise the temperature of water in streams as it runs off. This can speed the growth of bacteria and in turn deplete dissolved oxygen in the water. These pollutants and oxygen depletions can harm aquatic life.
Just like with a properly designed rain barrel, there is no reason to worry that having a raingarden will lead to mosquito problems. Seven to 12 days are required for mosquito eggs laid in standing water to hatch and mature to adults. A properly designed raingarden will contain standing water for only a few hours after most storms.
Therefore, consideration of the slope of the lawn, soil texture, rainfall amounts, the size of the catchment area, and the distance from the downspout to the raingarden all need to be taken into account to determine the right size for a raingarden.
Benefits of a raingarden include less storm water runoff, slower runoff, less pollution in runoff, more water to replenish groundwater supplies, and improved landscape quality. To learn more about raingardens and how to properly design one go to: http://bit.ly/2nW7Nzo.