Salt Water in our Aquifer. By Geniusofdespair

You can ignore all the other stuff. Look at our aquifer in pink. The canal system is also interesting, only because the 194 page report was primarily about the canal system.

Now that you know where our aquifer is, look at the salt water intrusion into it. That is why all the drinking wells are in Western Miami Dade County. Turkey Point is causing even more salt water intrusion.

U.S. Department of the Interior-U.S. Geological Survey Scientific Investigations Report 2014–5162 Prepared in cooperation with the Miami-Dade Water and Sewer Department 

Yes, I pulled these two quotes out of a 194 page report - link above. Not very fair. Read the report. HAH! Like that is going to happen. 

Canal and Biscayne aquifer water budgets for urban areas of the model indicate that most of the water discharging through the salinity control structures is derived from within the urban parts of the study area and that, on average, the canals are draining the Biscayne aquifer.  AND:

The effects of increased groundwater pumpage and (or) increased sea level on canal leakage and the position of the freshwater-seawater interface were evaluated using a modified version of the calibrated model to determine how the system may respond to future conditions. Permitted groundwater pumping rates were used for Miami-Dade Water and Sewer Department (MDWASD) groundwater pumping wells in the base-case future scenario. In general, permitted MDWASD groundwater pumping rates exceed historical groundwater pumping rates. As a result, base-case future and increased pumping scenario results suggest seawater intrusion may be an issue at the Miami-Springs well field if the Miami Springs, Hialeah, and Preston well fields are operated using current permitted groundwater pumping rates.