Distributed storage for urban runoff control: an analytical model.

A methodology is developed for predicting the long term performance of a system of two detention storage reservoirs in series using an analytical model which enables calculation of the expected seasonal runoff control, seasonal spill volume and seasonal number of overflows from each reservoir as well as for the total catchment. The model is found to be computationally efficient when compared with a simulation model while giving comparable results. The analytical methodology is intended to be used in the pre-screening and optimization phase of planning and design. Examples are presented showing the form of the analytical results and comparisons with simulation solutions. (A)