Roof Water Runoff Calculator

Take the dimensions of the footprint of your roof and convert them to inches.

Roof water runoff calculator.

For a rectangular house this is simply done by multiplying the length by the width of the roof. Standing water in your basement driveway or yard. Use the zoom tool in the lower right hand corner of the map to get closer so you can see draw on your roof. Calculate your drainage install on site.

The first is that it will size a rain garden for you that treats 1 of rainfall. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. The new nds app is the perfect tool for determining runoff and system requirements on the go. How to calculate roof runoff.

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. 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 catchment areais multiplied by the depth of rain that falls on it to give the total volumeof waterproduced. Box gutter with rain water head at end of box gutter. The calculator has two primary functions. It s one of the greatest threats to clean water in america today.

A simple rain catchment system can provide water for outdoor use resulting in. Calculate the total area of your 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. For a large roof it is recommended to have drains placed at multiple locations within the area of the roof.

Although this calculation is simple in principle the units can make it a headache. Increasing the angle of a flat roof will always increase the speed of water movement across the surface. 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. Rain barrels store and reuse rainwater helping to reduce the overtaxing of sewer systems and protect the quality of groundwater.

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.