Surface water withdrawals for Marcellus Shale gas development: performance of alternative regulatory approaches in the Upper Ohio River Basin.

Almost all of the water used for developing Marcellus Shale gas is withdrawn from surface water sources. State environmental and interstate water authorities take different approaches to managing these withdrawals. In the Upper Ohio River Basin, which covers the western third of Pennsylvania, the Pennsylvania Department of Environmental Protection requires that all water sources used for development have an approved water management plan. For surface water sources the plans stipulate the amount and timing of withdrawals from each source as a function of annual streamflow statistics. Neighboring regulatory authorities and some environmental groups now favor the use of monthly streamflow statistics to establish the conditions for water withdrawals. Our analysis indicates that, given the state of flow measurement data in the Upper Ohio River Basin, the annual streamflow statistics are more likely to prevent water withdrawals during the driest times of the year when aquatic ecosystems are most stressed, and to result in fewer and smaller occurrences of computed low-flow ecodeficits.