Multicriterion Stormwater Management Methods

Abstract

Both theory and experience indicate that, while detention basins designed to control peak discharge are effective in controlling peak rates, the basins are ineffective in controlling the degradation of erodible channels downstream of the basin. The increase in runoff volumes that accompanies land development causes greater rates of channel degradation because of the increased duration of high in‐bank flow rates. While planning and design procedures are available for peak discharge control, there has been a need for similar methods for the control of channel erosion and water quality. A relationship for making planning estimates of the volume of detention storage required to control channel erosion is provided. A procedure that can be used for design is also provided. Planning and design methods for water quality control through detention time control are also provided. The importance of adopting multicriterion stormwater management policies is emphasized, with the policy recommending control of flooding, channel erosion, and detention time for water quality enhancement.