Roof Water Runoff Calculator

Although this calculation is simple in principle the units can make it a headache.

Roof water runoff calculator.

Rain barrels store and reuse rainwater helping to reduce the overtaxing of sewer systems and protect the quality of groundwater. The drainage system of any roof can be located at the edge or in the middle of the 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. Box gutter with rain water head at end of box gutter.

Then click on the outer points of your roof and a polygon will instantly be created. It s one of the greatest threats to clean water in america today. Use the zoom tool in the lower right hand corner of the map to get closer so you can see draw on your roof. Once you have the square footage number enter it into the rainwater collection calculator above.

How to calculate roof runoff. Standing water in your basement driveway or yard. Factors such as evaporation wetting and soaking into the ground are not considered here. 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.

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. The first is that it will size a rain garden for you that treats 1 of rainfall. Calculate the total area of your roof. For a rectangular house this is simply done by multiplying the length by the width of the roof.

So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. The catchment areais multiplied by the depth of rain that falls on it to give the total volumeof waterproduced. Take the dimensions of the footprint of your roof and convert them to inches. Increasing the angle of a flat roof will always increase the speed of water movement across the surface.

For a large roof it is recommended to have drains placed at multiple locations within the area of the roof. 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 new nds app is the perfect tool for determining runoff and system requirements on the go.

Calculate your drainage install on site. National stormwater calculator help prevent pollution by controlling stormwater runoff. The calculator has two primary functions.