Introduction

The Mid-Atlantic Basin is composed of five major river systems: the Hudson River, Delaware River, Susquehanna River, Potomac River, and James River, going from north to south. The basin is home to about one-fifth of the country’s population, with about two-thirds of them living in the urban areas, including New York, Philadelphia, and Washington, D.C., near the coast and/or large rivers. While water resources in the region are generally abundant, periodic drought and pluvial (wet) events require careful management of water resources and the surrounding watersheds to minimize the negative impact of changes in water quantity and quality. Water managers face additional challenges because the Northeast U.S. is predicted to become both warmer and wetter in the coming decades. Increases in precipitation, seasonal streamflow, and a shift to earlier streamflow peaks in the winter and spring are projected. The expected changes in climate and hydrology, in combination with increasing population, will place greater demands on management of the region’s water resources.

Currently, water resource managers in the Mid-Atlantic Basin rely on instrumental records of precipitation and streamflow (<120 years) that are not adequate to assess variability in water quantity within the context of past centuries. Additional information on past variability in streamflow and hydroclimate will help managers better prepare for future changes in water quantity and quality. The signal recorded in moisture-sensitive trees in this region is generally not as strong as that found across much of the western U.S., but is still robust enough to provide useful information about past hydroclimate variability. Thus far, only streamflows for the Potomac River have been reconstructed using tree rings; however, additional reconstructions of drought and precipitation for the Mid-Atlantic Basin exist or are in development.