Green Roof Runoff Calculator

To help further promote green roof projects in the united states we decided to make our water runoff calculator tool available free of charge.

Green roof runoff calculator.

The excel based spreadsheet is available for download from the downloads and calculators page of the green roof blocks website. Note that there was very little if any runoff during the may 1 to sept 30 growing season. Figure 2 shows the daily rain and associated daily green roof runoff for 1993 in state college pa for a green roof having a maximum of 1 6 inches of water retention storage. Bioretention systems placed on roof surfaces that capture and temporarily store rainwater in a soil medium.

When these results were averaged over the 28 year simulation period a 3 5 inch. They are commonly used on individual home lots to capture roof runoff. Green infrastructure bmp options. Conventional development site conditions including roof size parking lot area and street sidewalk and driveway area.

They consist of a layered system of roofing designed to support plant growth and retain water for plant uptake while. Simulations are available for new construction ashrae 90 1 2004 and old construction pre ashrae 90 1 2004 office and residential buildings driven by typical precipitation and. The system outlined below will walk you through the steps of determining your rain barrel sizes based on average roof runoff. For sample purposes a 55 gallon barrel will be used.

Also outlined are the steps to build your own rain barrel to collect water from your roof and downspout for all outdoor uses like watering and cleaning.