The purpose of this study was to determine the change in water surface elevation and chloride concentration in the surficial, Mid Hawthorn, and Lower Hawthorn aquifers in the Cape Coral peninsula between 1980 and 1999. Seawater intrusion is a major concern in the Cape Coral area because the city is surrounded by open bodies of saline or brackish waters: Matlacha Pass to the west, San Carlos Bay to the south and Caloosahatchee River to the east. Prior to 1980, the principal groundwater withdrawals were from the Mid Hawthorn aquifer, with some smaller withdrawals from the surficial and Lower Hawthorn aquifers. Since 1980, many wells in the City of Cape Coral have been plugged and capped, decreasing the movement of water between the aquifers. In addition, withdrawals have primarily shifted to the Lower Hawthorn, which is now the principal water supply for the City of Cape Coral. Between 1980 and 1999 the water surface elevation in the surficial aquifer has remained relatively stable and chloride concentrations have decreased. During the same period, chloride concentrations have remained stable within the Mid Hawthorn aquifer. However, the potentiometric surface of the Mid and Lower Hawthorn has decreased and the chloride concentrations in the Lower Hawthorn in the vicinity of the City's wellfield have increased as a direct result of increased withdrawals. In addition, the area of highest chloride concentration within the City has moved west from its historic location, toward the City's reverse osmosis plant. The facility is roughly at the center of the wellfield that supplies water to the plant from the Lower Hawthorn. The potentiometric surface of the Mid Hawthorn has also decreased in the outlying areas of the Cape, mostly to the south and east, due to downward seepage into the Lower Hawthorn and well field pumping to the south in Ft. Myers, and east of Cape Coral along US 41.
| Date of Award | Jun 1 2000 |
|---|
| Original language | English |
|---|
| Supervisor | Curtis Burney (Supervisor), Eric Swain (Advisor) & Stacy Myers (Advisor) |
|---|