Saltwater Intrusion: Concepts For Measurements And A Regional Characterization For Broward County, Florida

Four basic components are necessary to properly manage our groundwater resources against saltwater intrusion;<br>measurement, monitoring, modeling and modification. While a discussion of the saltwater interface is presented to<br>provide an understanding of the hydrologic problems, this paper focuses on the first two steps in the process of<br>characterization; the measurements to define existing conditions of the saltwater interface and techniques for<br>monitoring changes in the saltwater interface over time.<br>A variety of techniques to measure the saltwater interface (both traditional and contemporary) are presented along<br>the their advantages and disadvantages. Two contemporary techniques are highlighted because of their dramatic<br>improvement in information which they provide: surface time domain electromagnetics (TDEM) and borehole<br>induction logging.<br>A county-wide case study is presented which utilized these contemporary techniques in Broward County, Florida.<br>The results of this study were used to map the saltwater interface, and identify anomalous conditions caused by<br>effects of head differences due to pumping, irrigation and saltwater recharge from canals as well as the presence of<br>“connate” saltwater in the aquifer. This regional characterization of the salhvater intrusion will be used to assess<br>the existing county-wide saltwater monitoring network and identify locations for future monitoring wells. The<br>approach for characterizing the extent of saltwater intrusion was unique and provided solid technical information<br>on the groundwater resources in which planning and development of the county can be based.