Roof Water Runoff Calculator

National stormwater calculator help prevent pollution by controlling stormwater runoff.

Roof water runoff calculator.

The area measurement will appear right above the map. Take the dimensions of the footprint of your roof and convert them to inches. Submit your design let nds evaluate and help you with preparation of your submittal drawings and specs. Calculate your drainage install on site.

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. Increasing the angle of a flat roof will always increase the speed of water movement across the surface. 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 catchment areais multiplied by the depth of rain that falls on it to give the total volumeof waterproduced. For a large roof it is recommended to have drains placed at multiple locations within the area of the roof. A simple rain catchment system can provide water for outdoor use resulting in. It s one of the greatest threats to clean water in america today.

Box gutter with rain water head at end of box gutter. 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. Factors such as evaporation wetting and soaking into the ground are not considered here.

For a rectangular house this is simply done by multiplying the length by the width of the roof. 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. The new nds app is the perfect tool for determining runoff and system requirements on the go.

Then click on the outer points of your roof and a polygon will instantly be created. Once you have the square footage number enter it into the rainwater collection calculator above. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. The first is that it will size a rain garden for you that treats 1 of rainfall.

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. To calculate the runoff from any given rainfall. The drainage system of any roof can be located at the edge or in the middle of the roof.