Providing basin-wide goals and standards for river flow management is a priority for the Delaware River Basin Commission (DRBC), The Nature Conservancy (Conservancy), and other partners. This project will result in flow recommendations based on ecological responses to flow alteration that DRBC can incorporate into water management planning and permitting, while meeting demands for water use.
The Conservancy proposes to facilitate a 12-month process to develop basin-wide ecosystem flow recommendations that can be implemented within the subwatersheds of the Delaware River. This process would follow the general model of other basin-scale projects that the Conservancy has been engaged in on large rivers, including a recent project on the Susquehanna River1 and a current project in the Pennsylvania portion of the Ohio River basin. The Conservancy will compile and interpret existing information on ecological health in relation to streamflow, including information from the Delaware basin and similar systems. The process incorporates at least two (possibly 3) technical workshops where relevant information and best professional judgment would be used to set ecosystem flow recommendations specific to the range of stream and river habitats within the basin.
Seasonal ecosystem-based flow recommendations would account for the range of flow conditions relevant ecosystem protection such as drought flows, seasonal base flows, and some high flow conditions. Along with magnitude of these flows, the process will also consider frequency and duration of flow conditions and the degree to which these conditions can deviate from minimally-altered flows conditions with limited ecological risk.