Rainfall slightly below average
BY DAN HILDEBRAN
Monitor Editor
PALATKA— The St. Johns River Water Management District said that even though rainfall during August of 6.89 inches was 0.11 inches below the long-term average, water levels on Lake Brooklyn rose nearly 8.5 inches during the month.
The increase brings the lake’s level to over 100 feet.
The district’s monthly rainfall report was presented to the organization’s governing board during the board’s Sept. 14 meeting and was summarized in a district news release. Other highlights of the report included:
Rainfall
Counties with the highest rainfall totals were Baker, with 9.2 inches of rain, followed by Nassau and Marion counties, which both received over 8 inches.
The counties with the least rainfall in August were Orange County with 5.5 inches, and Osceola County with 5.15 inches.
Districtwide, the cumulative rainfall total for the past 12 months is 52.8 inches, which is 1.83 inches above the long-term average.
Countywide rainfall totals for the past 12 months range from a high of 57.9” for Alachua to a low of 45.7” for Osceola.
Groundwater
Upper Floridan aquifer conditions at the end of August were either in the high or normal range throughout the district. Water levels in many of the wells used for this report increased more than 10 percentile points during the month.
Groundwater levels are at the 83rd percentile districtwide. This means that since 1980, aquifer levels have been higher than they currently are about 17% of the time.
Surface water flows
On Sept. 1, flow in most stations across the District was in the average range. The two exceptions were the St. Marys River, which had flow in the high range, and the tidal St. Johns River at Jacksonville station which exhibited very high flow on Sept. 1.
On Sept. 1, flow in the St. Johns River’s headwaters at the Melbourne station was 530 million gallons per day (mgd), which was in the 51st percentile.
Flows in the Econlockhatchee River near Chuluota were in the average range at 156 mgd (44th percentile).
Flows in the Wekiva River near Sanford were in the average range at 217 mgd (67th percentile).
Flows at the DeLand station were in the average range at 2.8 billion gallons per day (bgd) (59th percentile).
Flows in the Ocklawaha River, the largest tributary to the St. Johns River, were in the average range at 659 mgd (52nd percentile).
Flows at the St. Johns River near Satsuma station were in the average range at 7 bgd (72nd percentile).
Flows in the St. Marys River near Macclenny were in the high range at more than 717 mgd (80th percentile).
Lake levels
Lake Brooklyn water levels increased to 100.3 feet in August.
Lake Weir increased by 0.4 feet to 53.7 feet.
Lake Apopka’s water level of 65.7 feet did not change. Lake Apopka is part of a system with water control structures that are operated by the district to reduce flood impacts, and the lake level is regulated according to a specific schedule.
Blue Cypress Lake levels increased slightly to 21.8 feet, matching the regulation schedule for the time of year. Blue Cypress is also part of a system with water control structures that are operated by the district. During April and May, the regulation schedule levels begin to drop in preparation for the summer wet season.
Spring flows
The mean monthly flow at Silver Springs increased to 762 cubic feet per second (cfs), or 493 mgd, which is a 105 cfs increase from July’s mean.
At the Blue Spring station in Volusia County, the mean monthly flow was 136 cfs, or 88 mgd.
At Rock Springs, the monthly mean flow increased 2 cfs to 64 cfs (42 mgd), which is in the high range for August.
Mean monthly flow at Wekiwa Springs increased slightly to 68 cfs (44 mgd), which is in the normal range for the time of year.
