Low streamflow events may become more frequent and deliver lower water volumes

Submitted by dshannon on

Streamflow patterns may change in response to warming, and longer growing seasons to reduce low-streamflow volumes. Generally, within the Northeast, low flow trends may be eclipsed by increased stormflow from seasonal heavy precipitation events. At the same time, models suggest a greater frequency of reduced daily low-flow volumes in some areas of the region, such as localized areas within central New York, northern Maine, and along the Atlantic coast (Demaria et al, 2016). Altered winter precipitation that results in less snow, earlier snowmelt, and more variable seasonal precipitation may change soil water storage and groundwater recharge rates. Base streamflow conditions may be reduced as growing seasons become longer and warmer temperatures enhance evaporation rates and plant transpiration. Increases in water demand and usage to maintain public utility water supplies and agricultural requirements may also contribute to reductions in base streamflows (Hayhoe 2007, Demaria et al 2016). Drier climate conditions that alter the water balance and reduce baseflows may have the greatest hydrologic impact on sensitive systems such as headwater, ephemeral, and other small (low-order) perennial or intermittent systems.