Roof To Rain Garden Size

For example 600 square feet of my 1 200 square foot roof.

Roof to rain garden size.

The kind of soil you have will help determine the size of your rain garden. Identify only the area of roof that deposits water into the downspout you ve targeted for the rain garden. For this exercise i ve used square feet as a measurement. 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.

First identify the size of the roof driveway or other surface that will divert water into the rain garden. Most rain gardens are from 100 to 300 square feet. If necessary you may want to amend the soil in your planting area. Multiply your size factor by the drainage area to get your total garden size.

Residential rain gardens are often sized to hold one inch of runoff in above ground storage from the contributing impervious surface. 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. 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. This gives you the size to build the rain garden in square feet.

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. In this area of the country the majority around 90 of storms are one inch or less in size. Water is absorbed fastest in sandy soils and slowest in clay like soils. Sizing your rain garden.