Runoff Coefficient Metal Roof

Roof runoff has many outdoor uses.

Runoff coefficient metal roof.

For example it is 0 9 for metal or tile roofs and up to 0 3 for green roofs. Rational method runoff coefficients. Alternatively the runoff coefficient is the factor by which depending on the type of surface the effective impermeable area is calculated. A runoff coefficient is a number that relates the rainfall rate and runoff rate.

One of the parameters in the rational method equation q cia is the runoff coefficient c. I the design rainfall intensity for a storm of specified recurrence interval and duration equal to the watershed time of concentration. 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.

We can observe that there is a significant reduction in storage capacity compared to the first scenario. The runoff coefficient value is an attempt to take account of the volume of runoff which is absorbed into the surface. The other parameters are a the area of a watershed. There are two ways you can find the runoff coefficient.

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. This makes the duration different for all the events as it is based on the actual duration of the event. This is not a very precise variable and as such attempts have been made to remove it using statistical analysis of historical events. The runoff coefficient c is a dimensionless coefficient relating the amount of runoff to the amount of precipitation received.

One is by using the rational method and the other is by using a runoff coefficient. This coefficient accounts for the fact that some roof surfaces are more efficient than others at collecting rainwater. Using the runoff coefficient scientists and hydrologists can calculate how much water passes over a given area per second. Runoff coefficients when calculating the amount of runoff that can be harvested from a roof it is common to include a runoff coefficient.

Use it to wash cars and outdoor equipment and to rinse patios. 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. For example a pitched metal roof is typically the most efficient. 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.

And q the peak storm water runoff rate due to a storm of intensity i on. Unless the zinc content is particularly high it is safe to use on lawns and ornamental gardens.