Thursday, September 26, 2013: 8:35 a.m.-9:35 a.m.
Viewing groundwater across the Bay State you might not think of its many aquifers as small, especially the aquifers beneath Cape Cod and along the Connecticut River, but they are small compared to aquifers located throughout the western United States. Cape Cod, the largest aquifer in the Commonwealth, has a surface area of roughly 880 km2 including the non-aquifer moraine deposits. The aquifer beneath my house in New Mexico, the Albuquerque Basin, is ten times larger. I work in the San Luis Valley of Colorado, thirty times larger, the Central Valley of California, 65 times larger, and the Ogallala, 500 times larger (these systems are also stressed by a much drier climate). Most aquifers in the Bay State are much smaller than Cape Cod. What special challenges and opportunities are associated with Bay-State aquifers? Small aquifers are fast. By groundwater standards of behavior, Bay-State aquifer water levels and discharges respond quickly to perturbations of hydrology created by climate variability and change, and human impacts affecting recharge (e.g., land use) and discharge (e.g., pumping). Response times can be as short as months and is seldom longer than a few years. This sensitivity means that while groundwater quantity is resilient in the face of very short-term climate fluctuations or human pumping decisions, the impacts of longer-term climate signals and land use changes are effectively instantaneous. Small aquifers respond almost as quickly to perturbations of water quality, especially when the perturbations are associated with recharge and distributed in space, for example due to land use changes or the reuse of water. Understanding and managing fast responding systems require frequent observations, excellent data records, active recognition of feedbacks, and integration across hydrologic, disciplinary and policy boundaries. In the Bay State these issues are complicated by a growing dependence on bedrock aquifers, increasing interbasin water transfers (did you know the Albuquerque Basin partly relies on the transfer of Colorado River water?), and a newfound trust in large-scale water reuse, especially along the coastline (not unlike Orange County, California). This presentation will explore these and other Bay-State challenges and opportunities and contrast them to the state of affairs in the western United States
John Wilson, Ph.D.