Water Resources Research Act Program

Details for Project ID 2016MA452B

The stable isotopic composition of shallow and deep ground waters in Massachusetts

Institute: Massachuseits
Year Established: 2016 Start Date: 2016-05-01 End Date: 2017-04-30
Total Federal Funds: $23,141 Total Non-Federal Funds: $48,569

Principal Investigators: David Boutt

Abstract: Surface and ground water in the Northeast US are heavily impacted by intense land-use change, urbanization (Weiskel et al., 2007), and on-going climatic changes (Hodgkins et al., 2002; Hodgkins et al., 2003, Hunntington et al., 2004; Hayhoe et al., 2007). More emphasis is being placed on water suppliers, stakeholders, and environmental managers to assess water quantity and water quality with increasing confidence intervals for sustainable management (i.e. minimum streamflow rules) yet they lack the access to a complete set of tools for hydrologic assessment. Physical measures of hydrologic behavior (such as streamflow and water table elevation) provide one metric of system state and behavior but do not uniquely assess the connectedness and residence time of surface and ground waters (McDonnell et al., 2010). Additionally, physical characterization approaches require significant investment of resources and are subject to high degrees of spatial heterogeneity. Recently, advances in theory and instrumentation have allowed the wide-spread use of geochemical tracers (such as D and 18O isotopes in H2O) in combination with physical data to resolve discrepancies in measurements and reduce uncertainty in system conceptualization (IAEA, 2000). The applicability of these methods relies on a robust understanding of the seasonal behavior of precipitation and a background understanding of the isotopic behavior of surface and ground water isotopes. This work seeks to establish a regional-scale monthly record of the stable isotopic composition of ground and surface water in Massachusetts. By leveraging insights based on our previous hydro-climatic work (Weider and Boutt, 2010) and documenting the seasonal stable isotopic variability of these waters, we can assess important constraints on the seasonality of recharge, ground water residence times, sources of water to streams, and understanding the sensitivity of stream baseflow to seasonal hydrologic variability. We will gather existing regional isotopic measurements of precipitation, ground and surface waters combined with analyses collected in this work.