August rainfall above average; long-term total is still slightly below

From the St. Johns River Water Management District

Data collected by the St. Johns River Water Management District shows August 2019 rainfall was above average districtwide. Additionally, in a flipflop of recent months, Indian River County, which has been below average for many months, had the highest countywide rainfall total, with 10.2 inches.

A full report outlining hydrological conditions was presented at the district’s September Governing Board meeting.

Coastal central Florida continues to experience below-average rainfall. Flagler County had the district’s lowest monthly rainfall total at 3.3 inches for August, and Alachua and Marion counties were well above average for the month with nearly 10 inches of rain.

While more analysis will be included in next month’s report, Hurricane Dorian brought between 1–3 inches of rainfall across the district in early September, except for a narrow band of 4–5 inches in Flagler, western Volusia, and northeast Lake counties.

For the past 12 months, Indian River County has the lowest cumulative total at 41 inches, despite its 10.2 inches of welcome rainfall in August. Marion County has the highest 12-month total, at 58.9 inches.

Other hydrologic highlights include:

• Surface water flows in the Upper St. Johns River Basin were in the high to very high range (1.3 billion gallons) and in the very high range at the Ocklawaha River near the Conner monitoring station. Wekiva River flow was reported in the high range for the time of year, as it was in August.
• Lake levels in Lake Brooklyn and Lake Weir increased slightly, while Lake Winnemissett decreased a fraction.
• Flow at Silver Springs increased by 95 cubic feet per second (cfs) in August, while Rock Springs increased 3 cfs. Volusia Blue Spring decreased because high water levels in the spring run suppresses flow out of the spring. Flow at Wekiwa Springs ended August in the high range for the time of year.
• Upper Floridan aquifer conditions (groundwater levels) were in the normal to high range across the entire district except for a small area of low conditions in southeast Duval and northeast St. Johns counties.
• Groundwater levels are in the 85^th percentile, an increase of 16 percentile points since July. This means that only 15 percent of the time aquifer levels are higher than they are now.
• Water levels in most of the wells in the central and southern regions of the district increased compared to the previous month.

To learn more about rainfall totals, visit sjrwmd.com.

St. Johns River Water Management District staff are committed to ensuring the sustainable use and protection of water resources for the benefit of the people of the district and the state of Florida. The St. Johns River Water Management District is one of five districts in Florida managing groundwater and surface water supplies in the state. The district encompasses all or part of 18 northeast and east-central Florida counties. District headquarters are in Palatka, and staff also are available to serve the public at service centers in Maitland, Jacksonville, and Palm Bay.