Stormwater Level of Service

Storm water level of service (LOS) is a means of evaluating existing infrastructure and a basis for allocation of storm water resources. The challenge has been the determination of appropriate parameters for LOS evaluation. The management of storm water usually includes the reduction of flood risk and the improvement of water quality. There may be other objectives such as the protection of wetlands, water reuse, or the improvement of ground water recharge. While there is widespread agreement that water quantity and water quality objectives are linked, LOS criteria have, in most cases, been considered separately. The development of storm water LOS has been the purview of local government, and several different approaches have been proposed. While the objective seems to be a single parameter system that can be reduced to a letter grade from A to F, some have found it necessary to use multiple parameters to define the criteria. The maintenance status of the system has also been a level of service issue, and criteria for grading the maintenance status of a storm water facility have been proposed.