In this section
Miami Springs main view
A view of a boil at Miami Springs
Miami Springs is a third-magnitude spring with an elongated pool about 65 feet by 25 feet, with an average depth of about 3 feet. The pool has a sandy bottom, much of which was covered with algae and grass. Three prominent boils are located on the west side of the pool, with the largest vent about 5 feet in diameter and narrowing with depth. Water from the pool flows in a wide run about 35 feet wide for about 0.2 mile toward the north to the Wekiva River.
Miami Springs boil close-up
Discharge at Miami Springs was measured by the U.S. Geological Survey (USGS) in 1945 and 1960, then frequently from 1972 to 2002. St. Johns River Water Management District measured discharge from 1993 to 2010 and currently performs bimonthly discharge measurements. The difference between the minimum and maximum discharges is 4.48 cubic feet per second (cfs) over the period. The maximum measured discharge of 7.38 cfs occurred in October 1960; the minimum discharge of 2.9 cfs occurred in August 1977. The mean and median discharges for the period from 1945 to 2010 are 5.13 cfs and 5.14 cfs, respectively (see the table below).
Miami Springs was sampled by USGS in 1960, 1972, and 1995, with periodic field measurements only at other times. The district has sampled Miami Springs 58 times from 1993 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 Miami Springs
|Alkalinity, total, mg/L as CaCO3||73.5||111.3||113.0||135.0||59||1960−2010|
|Calcium, total, mg/L as Ca||27.0||34.9||35.4||38.0||57||1993−2010|
|Chloride, total, mg/L as Cl||5.5||11.9||11.3||30.7||60||1960−2010|
|Fluoride, total, mg/L as F||0.15||0.17||0.16||0.20||29||1993−2003|
|Magnesium, total, mg/L as Mg||6.8||9.3||9.5||10.1||57||1993−2010|
|Nitrate + nitrite, total, mg/L as N||0.01||0.16||0.13||0.54||53||1993−2010|
|Orthophosphate, total, mg/L as P||0.07||0.11||0.10||0.37||51||1995−2010|
|Phosphorus, total, mg/L as P||0.07||0.11||0.10||0.25||29||2001−2010|
|Potassium, total, mg/L as K||0.9||1.3||1.1||3.7||36||1993−2010|
|Sodium, total, mg/L as Na||5.0||6.9||6.2||22.0||57||1993−2010|
|Specific conductance, field, µmhos/cm at 25°C||158||267||273||313||57||1993−2010|
|Specific conductance, lab, µmhos/cm at 25°C||184||265||270||306||48||1960−2010|
|Sulfate, total, mg/L as SO4||3.0||11.8||11.6||24.5||61||1960−2010|
|Total dissolved solids, mg/L||103||153||154||194||56||1972−2010|
|Water temperature, °C||18.8||24.2||24.1||27.5||97||1960−2010|
mg/L = milligrams per liter
cfs = cubic feet per second
Age of discharge water
The age of water discharging from Miami Springs was determined by measuring the concentration of tritium, delta carbon-13, and carbon-14 in the spring discharge, which was measured in January 2001. Miami Springs had a tritium concentration of 1.35 tritium units, which suggests that the water is less than 48 years old. Miami Springs had a delta carbon-13 value of −10.3 parts per thousand and a carbon-14 concentration of 36% modern carbon, which results from the reaction of rainfall with calcite, dolomite, and sediment organic matter. The adjusted carbon-14 age of Miami Springs is recent.