- Take the dimensions of the footprint of your roof and convert them to inches. (So, a 50′ x 20′ roof is 600′′ x 240′′.)
- Multiply the roof dimensions by the number of inches of rainfall. (In this example, 600′′ x 240′′ x 1′′ = 144,000 cubic inches of water.)
How do you calculate rain water discharge?
There are several method that can be used to calculate drainage, but the rational method is probably the easiest and most widely used method. The rational method equation is:
Q = C x I x A/96.23
, where, Q is the storm-water run-off in gallons per minute (GPM)
How much water comes off my roof when it rains?
For example, on a 2,000 square foot roof, you can collect 2,000 x 0.56 = 1,120 gallons/inch of rain. If your average rainfall was 25 inches/year, your annual collection potential is 1,120 x 25=
28,000 gallons/year
.
How is stormwater runoff calculated?
To estimate runoff,
the amount of rainfall contributing to the runoff of a given area must be known
. The designer must estimate the runoff from predevelopment and postdevelopment conditions and design a stormwater management system to retain the excess quantity and treat the reduced quality of the water.
How do you calculate rainfall on a roof?
- Take the dimensions of the footprint of your roof and convert them to inches. (So, a 50′ x 20′ roof is 600′′ x 240′′.)
- Multiply the roof dimensions by the number of inches of rainfall. (In this example, 600′′ x 240′′ x 1′′ = 144,000 cubic inches of water.)
How many gallons of water does a roof take?
For example, on a 2,000 square foot roof, you can collect 2,000 x 0.56 =
1,120 gallons/inch
of rain. If your average rainfall was 25 inches/year, your annual collection potential is 1,120 x 25= 28,000 gallons/year.
How do you calculate runoff?
For a given surface area such as a roof or yard,
multiply the area by the inches of rainfall and divide by 231
to obtain the runoff in gallons.
What is rain runoff?
Stormwater runoff is
generated from rain and snowmelt that flows over land or impervious surfaces
, such as paved streets, parking lots, and building rooftops, and does not soak into the ground. … Rain gardens collect rain water from roofs, roads, and parking lots and allow it to soak into the ground.
How do you calculate rainfall flow?
- Take the dimensions of the footprint of your roof and convert them to inches. (So, a 50′ x 20′ roof is 600′′ x 240′′.)
- Multiply the roof dimensions by the number of inches of rainfall. (In this example, 600′′ x 240′′ x 1′′ = 144,000 cubic inches of water.)
How do you convert inches of rain to gallons?
Multiply the previous result by one inch of rainfall
. The result is that one inch of rain yields 4,014,489,600 cubic inches of water per square mile. Divide the result by 231 cubic inches per gallon, and obtain the result of 17,378,743 gallons per square mile for an inch of rainfall.
What is total runoff?
Runoff, in hydrology,
quantity of water discharged in surface streams
. … The total runoff is equal to the total precipitation less the losses caused by evapotranspiration (loss to the atmosphere from soil surfaces and plant leaves), storage (as in temporary ponds), and other such abstractions.
What is a runoff ratio?
Runoff ratio is
the runoff for each watershed divided by the precipitation for that watershed
. It is the proportion of rainfall that does not infiltrate and is not taken up by evapotranspiration, and thus ends up as runoff. … These areas will have high runoff ratios.
What is peak runoff?
One of the key parameters in the design and analysis of soil and water conservation structures is the resulting peak runoff or the variations of runoff with time (hydrograph) at the watershed outlet. … The
maximum flow at outlet
thus attained is called peak flow of runoff.
How much rain does it take to fill a rainwater tank?
This depends on how much rain you get, the size of the roof supplying the rain, plus how large the inflow pipe to your rainbarrel is. Typically,
one rain barrel will fill in just minutes in
an average downpour. One inch of rain on a 1000 square foot roof will yield around 600 gallons.
How quickly do rain barrels fill up?
It’s common for about 1/8′′ inch of rain to fall each hour during a moderate rainstorm. That means that a 500 square foot roof can fill a properly installed 50-gallon rain barrel
in about one hour
.
How much water does a person use a day?
Estimates vary, but, on average, each person uses about
80-100 gallons of water per day
, for indoor home uses. Are you surprised that the largest use of household water is to flush the toilet, and after that, to take showers and baths?
