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USGS1977

A digital model of the Floridan Aquifer, north of Tampa, Florida

A regional ground-water model of the Floridan aquifer was constructed for an 875-square-mile portion of the rapidly developing area north of Tampa Bay. The digital model was calibrated by comparing observed (March 1974 and May 1975) and computed potentiometric heads. A good comparison was obtained by adjusting leakance and transmissivity. Differences between the computed and measured potentiometric surface were generally less than 3 feet, with a maximum error of 15 feet. The calibrated model may be used as a predictive tool. For example, the model could be used to evaluate the regional effects of increased ground-water withdrawal on the Florida aquifer. (Woodard-USGS)

Water-Resources Investigations Report↗

USGS1977

Flood profiles of the Alafia River, west-central Florida, computed by step-backwater method

The Alafia River is a coastal stream that discharges into Hillsborough Bay. The river and its two principal tributaries, North Prong Alafia River and South Prong Alafia River, drain an area of 420 sq mi of predominantly rural land. However, near the coast, urban residential developments are increasing. The flood plain of the river is subject to flooding, particularly during large regional storms. Peak-discharge frequencies have been determined for data available at two gaging stations in the basin. The flood profiles for peak discharges of recurrence intervals of 2.33, 5, 10, 25, 50, 100, and 200 years have been determined using the step-backwater method. These profiles can be used in conjunction with topographic maps to delineate the area of flooding. Flood profiles were not determined for the tidally affected area near the mouth of the river. Flood marks were located that can be associated with the 1960 flood which occurred when Hurricane Donna passed over the area. (Woodard-USGS)

Florida↗