Roof Water Runoff Calculator

Standing water in your basement driveway or yard.

Roof water runoff calculator.

Take the dimensions of the footprint of your roof and convert them to inches. The catchment areais multiplied by the depth of rain that falls on it to give the total volumeof waterproduced. Increasing the angle of a flat roof will always increase the speed of water movement across the surface. 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.

For a rectangular house this is simply done by multiplying the length by the width of the roof. Calculate the total area of your roof. Whether you re an urban planner developer landscape architect or homeowner this tool can help you balance land developments and landscaping with the right amount of green infrastructure. The calculator has two primary functions.

The new nds app is the perfect tool for determining runoff and system requirements on the go. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. It s one of the greatest threats to clean water in america today. Calculate your drainage install on site.

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. The area measurement will appear right above the map. National stormwater calculator help prevent pollution by controlling stormwater runoff.

Factors such as evaporation wetting and soaking into the ground are not considered here. The drainage system of any roof can be located at the edge or in the middle of the roof. Simplified suitable for flattish roofs with little or no vertical faces or steep roofs draining to one side of box gutter only or any roof if you are in a hurry and make the necessary allowances for all catchments. The first is that it will size a rain garden for you that treats 1 of rainfall.

Rain barrels store and reuse rainwater helping to reduce the overtaxing of sewer systems and protect the quality of groundwater. How to calculate roof runoff. Although this calculation is simple in principle the units can make it a headache. A simple rain catchment system can provide water for outdoor use resulting in.

Box gutter with rain water head at end of box gutter. Use the zoom tool in the lower right hand corner of the map to get closer so you can see draw on your roof. For a large roof it is recommended to have drains placed at multiple locations within the area of the roof.