Water bodies, watersheds and storm water
Mud Spring main view
Mud Spring pool
Mud Spring boil
Mud Spring
Location
Mud Spring is located on state land about 1.5 miles south of Welaka. From the intersection of State Road 309 and SR 308B in Welaka, drive south on SR 309 for 1.5 miles and turn west onto State Forest Trail and continue past the gate for 1.1 miles. The spring is approximately 0.2 mile west of the trail.
Latitude 29°27’39.60” N, Longitude 81°39’41.40” W
Land grant sec. 40, T 12 S, R 26 E
Description
Mud Spring, locally known as Sulfur Spring, is a fourth-magnitude spring with an oval-shaped pool about 85 feet long and 65 feet wide. The spring flows from a vertical vent in the center of the pool, producing a prominent boil on the surface. The spring forms the head of Mud Creek, with the discharge flowing down a meandering run toward the southwest for about 1 mile to Little Lake George. The spring is situated along a hiking trail and is a popular picnic area in the state forest.
Discharge
Mud Spring boil close-up
Discharge at Mud Spring was measured by St. Johns River Water Management District (SJRWMD) 12 times from 1995 to 2001. The difference between the minimum and maximum discharges is 2.73 cubic feet per second (cfs) over the period. The maximum measured discharge of 3.16 cfs occurred in May 1978; the minimum discharge of 0.43 cfs occurred in May 1999. The mean and median discharges for the period are 1.16 cfs and 0.75 cfs, respectively (see the table below).
Water quality
Mud Spring was sampled 15 times by SJRWMD from 1995 to 2001. Summary statistics of the water quality data for selected variables are shown in the table below.
Summary statistics of water quality and discharge at Mud Spring
| Mud Spring | Min | Mean | Median | Max | Count | Period |
|---|---|---|---|---|---|---|
| Discharge, cfs | 0.43 | 1.16 | 0.75 | 3.16 | 12 | 1995–2001 |
| Alkalinity, total, mg/L as CaCO3 | 80.0 | 83.6 | 83.0 | 88.0 | 13 | 1995–2001 |
| Calcium, total, mg/L as Ca | 35.8 | 39.1 | 38.5 | 46.0 | 14 | 1995–2001 |
| Chloride, total, mg/L as Cl | 223.6 | 249.5 | 251.5 | 296.0 | 13 | 1995–2001 |
| Dissolved Oxygen | 0.36 | 0.36 | 0.36 | 0.36 | 1 | 2001 |
| Fluoride, total, mg/L as F | 0.14 | 0.15 | 0.15 | 0.17 | 14 | 1995–2001 |
| Magnesium, total, mg/L as Mg | 15.6 | 17.9 | 17.8 | 19.7 | 14 | 1995–2001 |
| Nitrate + nitrite, total, mg/L as N | 0.01 | 0.02 | 0.02 | 0.03 | 10 | 1996–2001 |
| Orthophosphate, total, mg/L as P | 0.06 | 0.08 | 0.08 | 0.11 | 14 | 1995–2001 |
| pH, field | 7.25 | 7.68 | 7.67 | 8.05 | 12 | 1995–2001 |
| Phosphorus, total, mg/L as P | 0.08 | 0.08 | 0.08 | 0.08 | 1 | 2001 |
| Potassium, total, mg/L as K | 3.8 | 4.4 | 4.2 | 5.4 | 14 | 1995–2001 |
| Sodium, total, mg/L as Na | 115.3 | 134.5 | 132.7 | 170.0 | 14 | 1995–2001 |
| Specific conductance, field, µmhos/cm at 25°C | 943 | 1056 | 1036 | 1272 | 14 | 1995–2001 |
| Specific conductance, lab, µmhos/cm at 25°C | 1010 | 1129 | 1117 | 1272 | 4 | 1995–2001 |
| Sulfate, total, mg/L as SO4 | 33.5 | 39.0 | 39.2 | 43.0 | 14 | 1995–2001 |
| Total dissolved solids, mg/L | 489 | 570 | 567 | 667 | 12 | 1995–2001 |
| Water temperature, °C | 22.4 | 22.8 | 22.8 | 23.2 | 15 | 1995–2001 |
mg/L = milligrams per liter
cfs = cubic feet per second
Age of discharge water
The age of water discharging from Mud Spring was determined by measuring the concentration of tritium, delta carbon-13, and carbon-14 in the spring discharge, which was measured in May 2001. Mud Spring had a tritium concentration of 2.69 tritium units, which suggests that the water is less than 48 years old. Mud Spring had a delta carbon-13 value of –8.98 parts per thousand and a carbon-14 concentration of 34% modern carbon, which results from the mixing of Upper and Lower Floridan aquifer water. The Fontes and Garnier (1979) carbon-14 age is 423 years old.
