a rainfall event of specified size and return frequency (e.g. a storm that occurs only once every two years) that is used to calculate the runoff volume and peak discharge rate to a BMP.
A rainfall event of specific size, intensity, and return frequency (e.g.,. the 1-year storm) that is used to calculate runoff volume and peak discharge rate.
A rainstorm used in the design of wastewater systems, primarily for systems which control combined sewer overflows. A particular storm may be selected as a design storm because adequate data exist to allow a calibration of a computer model being used to simulate the behavior of the sewer system during that storm.
A rainfall event of a specific size and return frequency (e.g., 2-year, 24-hour storm) that is used to calculate runoff volume and peak discharge rate to a BMP.
A rainfall event of specified size and return frequency(i.e., a storm what has the likelihood of occurring once every 10 or 100 years) that is used to calculate the runoff volume and peak discharge rate.
The expected return frequency of a storm event. Determined by the design engineer and used to lay out a stormwater system.
Coastal protection structures will often be designed to withstand WAVE attack by the extreme design storm. The severity of the storm (i.e. RETURN PERIOD) is chosen in view of the acceptable level of risk of damage or failure. A design storm consists of a DESIGN WAVE condition, a design WATER LEVEL, and a DURATION.
The storm duration and intensity for which a BMP or other structure is designed.
An selected storm event, described in terms of the probability of occurring once within a given number of years, for which drainage or flood control improvements are designed and built.
That particular storm which contributes runoff which the drainage facilities were designed to handle. This storm is selected for design on the basis of its probability of exceedance or average recurrence interval (See Probability of Exceedance.)
Rainfall amount and distribution in space and time, used to determine a design flood or design peak discharge.
