Conclusion

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The source of discharging ground water is chemically dilute ground water and surface water that enter from the northwestern side of Taylor Slough. The ultimate source is recharge of precipitation on Long Pine Key and the Rocky Glades.

During high-water, surface runoff from Long Pine Key that overflows Ingraham Highway to enter Taylor slough cannot be definitively separated from ground-water discharge, because both are relatively low in chloride concentration.

Shallow ground-water discharge is highest in reach 3, on the order of 1.2 cm/day, which is a factor of three larger than average daily evapotranspiration. Discharge in reach 2 is lower. Discharge in reach 4 is uncertain, because chloride generally increases in this reach and because we have not yet been able to rule out input of salt to reach 4 by tidal mixing. Surface water recharges the aquifer in reach 1 when the S-332 pump is operational (evident from comparison of S-332 pumping data and flow data at Taylor Slough Bridge).

Unfortunately, vertical discharge of deep ground water from directly beneath central Taylor Slough cannot be detected using chloride as a tracer. This is because of the similarity in chloride concentration between Taylor Slough surface water and ground water directly beneath the slough. For reaches 3 and 4, our preliminary estimate of ground-water discharge from directly beneath Taylor Slough (determined from measured vertical hydraulic gradients and hydraulic conductivity in peat) is 0.06 cm/day, which is only a minor component of the Taylor Slough water balance.

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Related information:

SOFIA Project: Groundwater-Surface Water Interactions and Relation to Water Quality in the Everglades