Flow-Regime Management at the Urban Land-Parcel Scale: Test of Feasibility

Abstract

Overcoming the hydrologic shortcomings of conventional approaches to stormwater management requires the protection or restoration of flow regimes at small scales. A better understanding of how stormwater management strategies can achieve this aim is needed. This study modeled 28,800 design configurations of a typical stormwater management strategy at the scale of urban land parcels across a range of urban densities and climatic conditions. Realistic design configurations that achieved three hydrologic response targets were identified as part of this modeling. It was found that meeting the targets required a combination of stormwater harvesting (using tanks) and infiltration (using rain gardens). This was possible primarily because the amount of harvested impervious roof runoff made a large contribution to a hydrologic target, which measured the ability to restore volumetric losses. Management of flow regimes at small scales will require policy mechanisms that necessitate both stormwater harvesting and infiltration. Urban design challenges remain to ensure that such approaches can be incorporated into the urban landscape in a way that maximizes the benefits to humans and to the environment. Future research is also required to investigate how the use of small-scale stormwater management strategies can improve catchment-scale flow regimes.