In this section
Wekiwa Springs main view
Wekiwa Springs pool
Wekiwa Springs main boil
Wekiwa Springs is a second-magnitude spring in a semitropical forest setting at the base of a northeast-sloping, grassy, open-wooded hillside. The springs form the headwater of the Wekiva River, a tributary to the St. Johns River. Two areas of discharge can be observed as surface boils near the edge in the southeast half of the pool. The strongest boil was over a large, irregularly shaped vent, about 35 feet long by 5 feet wide, located in the limestone bottom about 15 feet below the surface. The other boil was above a rock ledge in the extreme southeast edge of the pool. Except for the limestone rock bottom in the southeast part of the pool, the pool bottom was mostly sand. The spring pool is kidney-shaped, about 200 feet long and 100 feet wide, elongated southeast. A sidewalk surrounds the pool, and a wooden footbridge crosses the run just below the pool. A 2- to 3-foot high retaining wall encloses the pool and extends a short distance down the run. The clear, bluish-green water flows northeastward in a run 60 feet wide to the Wekiva River.
Wekiwa Springs is part of Wekiwa Springs State Park. The area provides camping, picnicking, swimming, fishing, boating, nature trails, and abundant wildlife.
Wekiwa Springs run
Discharge at Wekiwa Springs was measured by the U.S. Geological Survey (USGS) from 1932 to 2002. St. Johns River Water Management District measured discharge from 1983 to 2010 and currently performs bimonthly discharge measurements. In addition, discharge is also interpolated continuously from stage elevation and water levels measured in a nearby Floridan aquifer well. The difference between the minimum and maximum discharges is 62.64 cubic feet per second (cfs) over the period. The maximum measured discharge of 92.00 cfs occurred in October 1960; the minimum discharge of 29.36 cfs occurred in November 1985. The lowest periods of discharge correspond to periods of below normal rainfall in Florida. The mean and median discharges for the period from 1932 to 2010 are 66.68 cfs and 66.51 cfs, respectively (see the table below).
Wekiwa Springs was sampled by USGS from 1956 to 2003. The district sampled Wekiwa Springs from 1984 to 2010 and currently samples the spring four times per year. Summary statistics of the water quality data for selected variables are shown in the table below.
Summary statistics of water quality and discharge at Wekiwa Springs
|Alkalinity, total, mg/L as CaCO3||72.0||118.1||122.0||140.0||133||1956−2010|
|Calcium, total, mg/L as Ca||25.6||39.7||40.0||45.5||103||1992−2010|
|Chloride, total, mg/L as Cl||7.0||14.1||14.1||27.0||139||1956−2010|
|Fluoride, total, mg/L as F||0.12||0.16||0.15||0.21||54||1994−2009|
|Magnesium, total, mg/L as Mg||7.7||11.3||11.3||13.1||103||1992−2010|
|Nitrate + nitrite, total, mg/L as N||0.34||1.21||1.21||2.00||108||1977−2010|
|Orthophosphate, total, mg/L as P||0.06||0.11||0.11||0.15||80||1972−2010|
|Phosphorus, total, mg/L as P||0.01||0.14||0.12||2.04||66||1972−2010|
|Potassium, total, mg/L as K||1.2||1.6||1.6||2.5||103||1992−2010|
|Sodium, total, mg/L as Na||4.7||9.3||9.5||11.0||103||1992−2010|
|Specific conductance, field, µmhos/cm at 25°C||191||322||326||398||111||1984−2010|
|Specific conductance, lab, µmhos/cm at 25°C||192||304||316||371||135||1956−2010|
|Sulfate, total, mg/L as SO4||6.0||18.4||19.1||23.0||139||1956−2010|
|Total dissolved solids, mg/L||101||179||183||218||130||1959−2010|
|Water temperature, °C||22.0||23.7||23.7||25.7||217||1956−2010|
mg/L = milligrams per liter
cfs = cubic feet per second
Age of discharge water
The age of water discharging from Wekiwa Springs was determined by measuring the concentration of tritium, delta carbon-13, and carbon-14 in the spring discharge, which was measured in April 1995, and tritium and helium-3, as measured in July 1995. Wekiwa Springs had a tritium concentration of 3.0 tritium units, which suggests that the water is less than 42 years old. The tritium/helium-3 age of the water was 17 years. Wekiwa Springs had a delta carbon-13 value of −10.14 parts per thousand and a carbon-14 concentration of 50% modern carbon, which results from the reaction of rainfall with calcite, dolomite, and soil organic matter. The adjusted carbon-14 age of Wekiwa Springs is recent. The three ages indicate that the water discharging from Wekiwa Springs is young.