Roof Water Runoff Calculator

National stormwater calculator help prevent pollution by controlling stormwater runoff.

Roof water runoff calculator.

The first is that it will size a rain garden for you that treats 1 of rainfall. For a rectangular house this is simply done by multiplying the length by the width of the roof. Factors such as evaporation wetting and soaking into the ground are not considered here. Although this calculation is simple in principle the units can make it a headache.

The area measurement will appear right above the map. The new nds app is the perfect tool for determining runoff and system requirements on the go. If your roof plan is more complicated break it up into smaller more easily calculable areas and then add those areas together for the total area. Standing water in your basement driveway or yard.

Take the dimensions of the footprint of your roof and convert them to inches. The drainage system of any roof can be located at the edge or in the middle of the roof. How to calculate roof runoff. A simple rain catchment system can provide water for outdoor use resulting in.

The catchment areais multiplied by the depth of rain that falls on it to give the total volumeof waterproduced. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. Once you have the square footage number enter it into the rainwater collection calculator above. Use the zoom tool in the lower right hand corner of the map to get closer so you can see draw on your roof.

Box gutter with rain water head at end of box gutter. It s one of the greatest threats to clean water in america today. For a large roof it is recommended to have drains placed at multiple locations within the area of the roof. Increasing the angle of a flat roof will always increase the speed of water movement across the surface.

Then click on the outer points of your roof and a polygon will instantly be created. Calculate the total area of your roof. Stormwater runoff calculator this calculator allows you to simulate the effects that installing a rain garden a type of green infrastructure could have on stormwater runoff from your property. The calculator has two primary functions.

To calculate the runoff from any given rainfall. Submit your design let nds evaluate and help you with preparation of your submittal drawings and specs. Calculate your drainage install on site.