Stressed Watersheds in a Rainfall-Rich Region

Southern New England has ample rainfall and, in some years, snowmelt, to sustain reservoirs and aquifers that are used primarily for municipal water supplies and secondarily for industrial and agricultural needs. Despite the humid climate, however, many watersheds are considered stressed, particularly during the summer and early fall growing-season months due to the combined effect of evapotranspiration and increased demand for lawn irrigation and other seasonal, warm-weather uses. While per capita consumption is frequently the focus of water-conservation efforts, most high-stress areas are in population centers where concentrated demand exceeds recharge (to aquifers) or runoff (to surface water supplies) within the region's small watersheds (commonly 200 mi2 or less). The parameter depletion intensity, described by Konikow (2015) in a review of groundwater-depletion trends across the United States, is used to compare seasonal stress and changes in stress level in several watersheds in Massachusetts. Areas of stress follow patterns of high depletion intensity during the summer months when demand is high. This seasonal stress is exacerbated by inter-basin transfer of water or wastewater from a watershed. Examples will be presented of projects where streamflow impacts have been offset using tools including well optimization, water conservation, storm water recharge, and reductions of infiltration/inflow to utilities, pursuant to the state's Sustainable Water Management Initiative.