Roof To Rain Garden Size

The size and depth of the rain garden the infiltration rate of the soil the size of the uphill drainage area the amount of impervious or semi impervious surfaces rooftops driveways sidewalks and mowed turf in the uphill drainage area the slope of the site and the amount intensity and duration of rainfall all influence rain garden effectiveness in managing rainwater runoff.

Roof to rain garden size.

For the next steps in the planning process go to earth partnership for schools activities de signing a rain garden and rain garden species selection extensions. If necessary you may want to amend the soil in your planting area. The kind of soil you have will help determine the size of your rain garden. If you are placing your rain garden more than 30 feet from a downspout take the yard space into account when you figure the drainage area.

For example 600 square feet of my 1 200 square foot roof. Measure the distance from the house and the width of the drainage area and add it to your roof figure and find the soil type for your garden. Water is absorbed fastest in sandy soils and slowest in clay like soils. In this area of the country the majority around 90 of storms are one inch or less in size.

Sizing your rain garden. Most rain gardens are from 100 to 300 square feet. Natural looking and kidney bean shapes are popular. Determine rain garden size for 100 runoff control 1.

Residential rain gardens are often sized to hold one inch of runoff in above ground storage from the contributing impervious surface. Identify only the area of roof that deposits water into the downspout you ve targeted for the rain garden. Multiply total drainage area by the soil factor. This gives you the size to build the rain garden in square feet.