Estimated Hydrology of the Pre-drainage System [circa 1900]1

The synthetic satellite image shown on the left is an attempt to reconstruct the view of the landscape that was likely to have existed circa 1850. Note the broad extent of the ridge and slough communities.

Estimates of the primary water budget components for the predrained system are shown in the water budget map (right). Although large volumes flowed to the Atlantic Ocean via small rivers (transverse glades), the region now defined as Everglades National Park received significantly more surface water flows from the north and from the east than it does today.

Ponding Depth and Hydroperiod Patterns

The map above on the left illustrates average simulated predrainage surface water ponding depths and overland flow patterns. The hydroperiod map above on the right shows the average number of days during a typical year that the region was inundated. The levees and canals of the current system did not exist circa 1850, and they are shown for geographic reference only.

The pre-drainage system was characterized by a broad spatial extent of surface water which persisted over a large area. The slow moving 50-mile wide, 100-mile long "river of grass" extended from Lake Okeechobee to Florida Bay and the Gulf of Mexico.

As a precursor to ecological restoration of the Everglades, current efforts are focused on enhancing the hydrologic characteristics of the remaining Everglades to more closely mimic those of the predrainage Everglades system. Achieving hydrologic restoration does not guarantee ecological restoration; however it is assumed that reconstructing the natural or pre-drained hydrologic characteristics will provide maximum opportunity for recovery of the remaining Everglades landscape patterns and Everglades wildlife.

¹Source: SFWMD Hydrologic Systems Modeling Division. Natural System Model (NSM) Version 4.5. The NSM simulates the hydrologic response of the pre-drainage Everglades system to historical (1965-95) meteorologic data.

Where does the water go today?