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Research about St. Johns River Water Management District and vicinity

Source-linked reports with geographic coverage including St. Johns River Water Management District and vicinity.

12 recordsLinked to original sources
USGS2008

Potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity, May 2008

This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2008. Potentiometric contours are based on water-level measurements collected at 567 wells during the period May 6-May 27, near the end of the dry season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours. Measured values of the potentiometric surface ranged from 7 feet below NGVD29 near Fernandina Beach, Florida, to 124 feet above NGVD29 in Polk County, Florida. The average water level of the network in May 2008 was about 1 foot lower than the average in September 2007 following below-average rainfall during the dry season of 2007-08. Seasonal differences in network average water levels generally range from 4 to 6 feet. For 457 wells with previous measurements, May 2008 levels ranged from about 19 feet below to about 11 feet above September 2007 water levels. The average water level of the network in May 2008 was about 1 foot higher than the average in May 2007. For 544 wells with previous measurements, May 2008 levels ranged from about 8 feet below to about 13 feet above May 2007 water levels. Long-term hydrographs of ground-water levels for continuous and periodic wells are available at internet site: http://waterdata.usgs.gov/fl/nwis/gw

Florida↗
USGS2004

Potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, May 2004

This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity in May 2001. Potentiometric contours are based on water-level measurements collected at 684 wells during the period May 2 - 30, near the end of the dry season. The shapes of some contours have been inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

Florida↗
USGS1988

Potentiometric surface of the upper Floridan Aquifer in the St. Johns River Water Management District and vicinity, Florida, May 1988

This map shows the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity, for May 1988. The Upper Floridan aquifer is the principal source of potable water in the area. Water level measurements were made on approximately 1,000 wells and on several springs. The potentiometric surface is shown mostly by 5-foot contour intervals. In the Fernandina Beach area of Nassau County, a 30-foot interval is used to show a deep cone of depression. The potentiometric surface ranged from 127 ft above sea level in Polk County to 79 ft below sea level in Nassau County. Water levels in many key wells were about the May average. Most levels in the district were below the levels of May 1987. Declines of about a foot or less from May 1987 levels were common along the coast, but inland, the potentiometric surface declined as much as 2 to 6 ft in places.

Florida↗
USGS1987

Potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity, Florida, September 1987

This map shows the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for September 1987. The Upper Floridan aquifer is the principal source of potable water in the area. Water level measurements were made on approximately 1,000 wells and on several springs. The potentiometric surface is shown mostly by 5-foot contour intervals. The potentiometric surface ranged from 129 feet above sea level in Polk County to 77 feet below sea level in Nassau County. Water levels in most key wells ranged from 0 to 10 feet below in May 1987 levels in response to the lack of recharge from rainfall and an attendant increase in pumpage. Declines of about 0 to 3 feet from May 1987 levels were common in most areas of the district. However, the largest declines from May 1987 levels, as much as 7 to 10 feet, were mostly in well fields along the coastline. Many levels in the district were equal to or lower than the average levels of September 1986.

Florida↗