Water bodies, watersheds and storm water
Tobacco Patch Landing Springs aerial view
Tobacco Patch Landing Springs pool
Tobacco Patch Landing Springs vent
Tobacco Patch Landing Springs
Location
Tobacco Patch Landing Springs is located about 5 miles north of Eureka. The spring is submerged in Rodman Reservoir and can best be reached by boat. From the Eureka Dam boat ramp, go north (downriver) about 4 miles and the spring is near the east bank.
Latitude 29°25’42.73” N, Longitude 81°55’26.09” W
NW¼ SW¼ SW¼ sec. 20, T 12 S, R 24 E
Description
Tobacco Patch Landing Springs is a third-magnitude spring that is normally submerged by 4 to 5 feet of water when Rodman Reservoir is at capacity. At times of drawdown in the Rodman Reservoir, the spring pool and vent are more easily discernible (see photographs). The circular pool of the main spring is set at the base of a hill overlooking Rodman Reservoir. The vent is approximately 12 to 15 feet across, with a rock ledge visible on its northern side. During an observed period of low water in the reservoir, water flowed southwest out of the pool and was joined by water coming from the east, and the combined run flowed to the west approximately 0.25 mile to the Ocklawaha River. The source of the water from the east was not determined. About 300 feet west of the spring pool another stream joined the spring run from the southeast, but the source of this water also could not be determined.
Discharge
Tobacco Patch Landing Springs pool and run
Discharge from Tobacco Patch Landing Springs was measured from the spring pool in March 1999 by the U.S. Geological Survey (USGS), at 2.8 cubic feet per second (cfs). Discharge, sampled on the spring run below the confluence with the nearby stream, was measured in February 2002 by the St. Johns River Water Management District (SJRWMD), at 4.98 cfs. SJRWMD also measured discharge twice in 2008. The mean discharge for the period of record is 3.92 cfs (see the table below).
Water quality
Tobacco Patch Landing Springs was sampled by USGS in 1999 and by SJRWMD in 2002. A summary of the water quality data for selected variables is shown in the table below.
Summary statistics of water quality and discharge
at Tobacco Patch Landing Springs
| Tobacco Patch Landing Springs | Min | Mean | Median | Max | Count | Period |
|---|---|---|---|---|---|---|
| Discharge, cfs | 2.80 | 3.92 | 3.95 | 4.98 | 4 | 1999–2008 |
| Alkalinity, total, mg/L as CaCO3 | 69.4 | 69.4 | 69.4 | 69.4 | 1 | 2002 |
| Calcium, total, mg/L as Ca | 80.0 | 80.0 | 80.0 | 80.0 | 1 | 2002 |
| Chloride, total, mg/L as Cl | 540.0 | 544.0 | 544.0 | 548.0 | 2 | 1999–2002 |
| Fluoride, total, mg/L as F | 0.14 | 0.14 | 0.14 | 0.14 | 1 | 2002 |
| Magnesium, total, mg/L as Mg | 33.0 | 33.0 | 33.0 | 33.0 | 1 | 2002 |
| Nitrate + nitrite, total, mg/L as N | 0.17 | 0.17 | 0.17 | 0.17 | 1 | 2002 |
| Orthophosphate, total, mg/L as P | 0.02 | 0.02 | 0.02 | 0.02 | 1 | 2002 |
| pH, field | 6.11 | 6.81 | 6.81 | 7.50 | 2 | 1999–2002 |
| Potassium, total, mg/L as K | 9.2 | 9.2 | 9.2 | 9.2 | 1 | 2002 |
| Sodium, total, mg/L as Na | 297.5 | 297.5 | 297.5 | 297.5 | 1 | 2002 |
| Specific conductance, field, µmhos/cm at 25°C | 2124 | 2124 | 2124 | 2124 | 1 | 2002 |
| Specific conductance, lab, µmhos/cm at 25°C | 2100 | 2100 | 2100 | 2100 | 1 | 1999 |
| Sulfate, total, mg/L as SO4 | 160.0 | 162.8 | 162.8 | 165.6 | 2 | 1999–2002 |
| Total dissolved solids, mg/L | 1100 | 1140 | 1140 | 1180 | 2 | 1999–2002 |
| Water temperature, °C | 22.6 | 22.7 | 22.7 | 22.7 | 2 | 1999–2002 |
mg/L = milligrams per liter
cfs = cubic feet per second
