How Much Runoff In Washington Roof

In this example 600 x 240 x 1 144 000 cubic inches of water.

How much runoff in washington roof.

If your roof plan is more complicated break it up into smaller. For example in 2001 during a major storm at peachtree creek in atlanta georgia the amount of water that flowed in the river in one day was 7 percent of all the streamflow for the year. Before you know what size rain barrels or cisterns to install you will need to calculate the average amount of rain runoff from your roof. Step 1 calculate the total area of your roof.

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. To get an idea how much water the roof of your own house might yield use the rainfall harvest calculator above. Runoff of course occurs during storms and much more water flows in rivers and as runoff during storms. The system outlined below will walk you through the steps of determining your rain barrel sizes based on average roof runoff.

Then just open the drain valve in october and let the barrel slowly drain out between big storms to slow our runoff all winter. Just a half inch of rain falling on a 1 000 square foot roof will yield 300 gallons of water. Rain barrel supplies list. I do suggest hanging gutters as high as possible so that water does not over shoot them.

1981 2010 source national weather service. When you look at the numbers it s surprising how much water you can collect every time it rains. When installing a metal roof that has considerable formed thickness to is such as a shake or tile profile using 6 gutters would work better than 5 again to keep. For a rectangular house this is simply done by multiplying the length by the width of the roof.

The study plan can be found at the link below. To calculate the runoff from any given rainfall. The 2016 wsc project design calls for chemical analysis of the roof runoff and will test zebrafish coho salmon juveniles and a water bug called ceriodaphnia dubia for acute toxicity from the runoff water. For sample purposes a 55 gallon barrel will be used.

The anacostia watershed society offers a rebate of 10 to 15 per square foot to help defray costs of installing a green roof. So a 50 x 20 roof is 600 x 240 multiply the roof dimensions by the number of inches of rainfall. My own house with a metal roof of course is a 12 12 pitch and everything is just fine. You can help solve our winter stormwater runoff problems by connecting a hose to the drain valve on your rain barrel or cistern and running it out into a lawn or landscape.