Runoff Coefficient Metal Roof

It is a larger value for areas with low infiltration and high runoff pavement steep gradient and lower for permeable well vegetated areas forest flat land.

Runoff coefficient metal roof.

Assuming a peak possible rainfall of 150 mm over a 24 hour time period and the available roof catchment of 200 sq m the storage capacity will be. This coefficient accounts for the fact that some roof surfaces are more efficient than others at collecting rainwater. 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. Using the runoff coefficient scientists and hydrologists can calculate how much water passes over a given area per second.

For example a pitched metal roof is typically the most efficient. The runoff coefficient value is an attempt to take account of the volume of runoff which is absorbed into the surface. For example it is 0 9 for metal or tile roofs and up to 0 3 for green roofs. A runoff coefficient is a number that relates the rainfall rate and runoff rate.

Runoff coefficients when calculating the amount of runoff that can be harvested from a roof it is common to include a runoff coefficient. Rational method runoff coefficients. The system outlined below will walk you through the steps of determining your rain barrel sizes based on average roof runoff. The runoff coefficient c is a dimensionless coefficient relating the amount of runoff to the amount of precipitation received.

Runoff generated roof area peak rainfall runoff coefficient 200 150 0 9 7100 gallons. One of the parameters in the rational method equation q cia is the runoff coefficient c. And q the peak storm water runoff rate due to a storm of intensity i on. Roof runoff has many outdoor uses.

This is not a very precise variable and as such attempts have been made to remove it using statistical analysis of historical events. This makes the duration different for all the events as it is based on the actual duration of the event. Why is it important. One is by using the rational method and the other is by using a runoff coefficient.

Unless the zinc content is particularly high it is safe to use on lawns and ornamental gardens. For sample purposes a 55 gallon barrel will be used. There are two ways you can find the runoff coefficient. Use it to wash cars and outdoor equipment and to rinse patios.

I the design rainfall intensity for a storm of specified recurrence interval and duration equal to the watershed time of concentration. We can observe that there is a significant reduction in storage capacity compared to the first scenario.