Decentralized urban water infrastructure systems

Urban water management can be improved by the use of water budget analysis in conjunction with GIS to form a Decision Support System (DSS). An application of these techniques is presented at a variety of spatial and temporal scales. Microscale techniques can improve water management, particularly by integrating stormwater and water supply management. A modeling approach is presented which incorporates decentralized options for management of both stormwater and urban water supply. The effects of outdoor water conservation/demand management options are investigated and the resultant impact on downstream runoff is estimated. Management options that can be evaluated with this approach include refined irrigation policies and rainwater harvesting. A simple metamodel is developed and calibrated to the more complex model using a commercially available nonlinear solver. The metamodel is then used to evaluate the long term downstream hydrologic effects of the selected irrigation management option. A method for comparison of costs and benefits from a consumer perspective is presented, and a least cost evaluation is made.