In this section
Juniper Springs main view
Juniper Springs pool
Juniper Springs vent
Juniper Springs is a second-magnitude spring with an oval-shaped pool that measures about 120 feet from north to south and 90 feet from east to west. Several limestone vents and sand boils are present on the pool bottom, with sand and aquatic grasses in other areas of the pool. The clear, bluish water has a low dissolved solids concentration compared with most Florida springs. A limestone and concrete wall with steps and other access points surrounds the pool. An old millhouse and spillway are on the east side of the pool. Numerous sand boils are located down the run from the main pool, with the largest by the bridge over the run. The springs are the headwaters of Juniper Creek, which meanders toward the northeast through the Juniper Prairie Wilderness for about 10 miles to Lake George. Fern Hammock Springs are located about 0.25 miles downstream from Juniper Springs. The springs and the surrounding recreational area provide facilities for camping, picnicking, swimming, snorkeling, hiking, and canoeing.
Juniper Springs outlet
Discharge at Juniper Springs was measured by the U.S. Geological Survey (USGS) 57 times from 1908 to 2002. St. Johns River Water Management District measured discharge 189 times from 1983 to 2010 and currently measures discharge six times per year. The difference between the minimum and maximum discharges is 16.3 cubic feet per second (cfs) over the period. The maximum discharge of 16.8 cfs was measured in July 1936; the minimum discharge of 0.5 cfs was measured in February 1931. The mean and median discharges for the period from 1908 to 2010 are 10.93 cfs and 11.00 cfs, respectively (see the table below).
Juniper Springs was sampled by USGS in 1908 and eight times from 1956 to 1980, with periodic field measurements through 1999. The district sampled the spring quarterly for most years from 1984 to 2010 and continues to sample 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 Juniper Springs
|Alkalinity, total, mg/L as CaCO3||21.0||45.3||45.0||89.6||124||1956−2010|
|Calcium, total, mg/L as Ca||8.0||12.9||13.0||14.5||106||1992−2010|
|Chloride, total, mg/L as Cl||3.5||4.8||4.4||14.9||122||1956−2010|
|Fluoride, total, mg/L as F||0.05||0.07||0.07||0.13||54||1989−2009|
|Magnesium, total, mg/L as Mg||3.8||4.5||4.5||5.1||105||1992−2010|
|Nitrate + nitrite, total, mg/L as N||0.04||0.09||0.08||0.17||109||1984−2010|
|Orthophosphate, total, mg/L as P||0.01||0.02||0.02||0.04||73||1994−2010|
|Phosphorus, total, mg/L as P||0.01||0.03||0.03||0.05||63||1996−2010|
|Potassium, total, mg/L as K||0.3||0.4||0.3||1.2||18||1994−2010|
|Sodium, total, mg/L as Na||2.0||2.7||2.7||4.0||105||1992−2010|
|Specific conductance, field, µmhos/cm at 25°C||62||125||116||1146||110||1984−2010|
|Specific conductance, lab, µmhos/cm at 25°C||102||117||116||159||105||1908−2010|
|Sulfate, total, mg/L as SO4||3.9||6.4||6.0||15.0||123||1956−2010|
|Total dissolved solids, mg/L||33||67||66||94||116||1962−2010|
|Water temperature, °C||20.0||21.9||22.0||25.1||142||1908−2010|
mg/L = milligrams per liter
cfs = cubic feet per second
Age of discharge water
The age of water discharging from Juniper Springs was determined by measuring the concentration of tritium, delta carbon-13, and carbon-14 in the spring discharge, which was measured in April 1996, and the concentration of tritium and helium-3 in the discharge, as measured in March 2001. Juniper Springs had a tritium concentration of 4.2 tritium units, which suggests that the water is less than 43 years old. The tritium/helium-3 age was 25 years. Juniper Springs had a delta carbon-13 value of −9.5 parts per thousand and a carbon-14 concentration of 31% modern carbon, which results from the reaction of rainfall with calcite, dolomite, and sediment organic matter. The adjusted carbon-14 age is recent.