A hydraulic invariance-based methodology for the implementation of storm-water release restrictions in urban land use master plans

A hydraulic invariance (HI)-based methodology was developed as a tool to support implementation of storm flow control measures into land use master plans (LUMPs) for urban catchments. The methodology is based on the use of simple hydrologic analysis to compare predevelopment and postdevelopment catchment flow release scenarios. Differently from previous literature examples, for which the parcel scale is usually considered for the analysis, HI was pursued assuming the LUMP areas of transformation as the basic units for assigning storm water control measures in the form of flow release restrictions. The methodology was applied to a case study catchment in the southern part of the City of Catania (Italy), for which the LUMP re-design has been recently proposed. Simulations were run based on the use of the EPA-Storm Water Management Model and allowed deriving flow release restrictions in order to achieve HI at the subcatchment level for design events of different return period.