Integrating Raw Water Transfers into an Eastern United States Management Context

Abstract

In the eastern United States, intermittent transfers of treated water are being used more often as a drought management tool; however, untreated raw water transfers, similar to those observed in the western US, are rare. Nonetheless, raw water transfers, free of most physical and financial constraints associated with treating and piping water, are possible within an eastern US regulatory context and could aid in meeting future demands while delaying or avoiding expensive infrastructure. This study demonstrates how raw water transfer schemes along a common river course can influence trade-offs between reliability and financial objectives in the Research Triangle in North Carolina. Regional utility actions are simulated under a wide range of future hydrologic conditions with and without raw water transfer schemes available. Raw water transfers are found to maintain regional supply reliability while reducing demand management interventions. Raw water transfers also significantly reduce politically contentious interbasin water transfers, as well as lowering regional financial risk and long-term debt through decreased dependence on infrastructure and increased planning flexibility. Relaxing US Army Corps of Engineers rules related to the accounting of reservoir inflows as applied to raw water transfers was also observed to improve regional objectives.