Graphical estimation of detention pond volume for rainfall of short duration

This study uses the hydrological continuity equation to establish a numerical model according to the detention pond routing phenomena. Then the numerical model is used to develop a series of charts using the dimensionless equation and simplification procedure. These charts can be used to calculate the maximum detention volume by giving characteristics of detention pond shapes, outflow device and triangular inflow hydrograph. A series of examples are adopted to illustrate the procedure of graphical estimation. Based on the examples presented in this paper, the detention volume difference between that estimated from the charting methodology and that generated from the numerical model is within 3%. These charts are useful for determining the needed parameters for detention pond design with inflow hydrographs, detention pond configurations, and outflow devices.