Southwest Florida Water Management District Tampa


From 2007 – To 2009

The final report was submitted to USEPA to support TMDL development.


Key Staff

Paul Craig, P.E.

[email protected]

Kester Scandrett

[email protected]


The Southwest Florida Water management District (SWFWMD) was in the process of developing methods and rules for the establishment and implementation of Minimum Flows and Levels (MFL) for priority water bodies within its jurisdiction. As part of their methods development process and to address a specific priority site they contracted DSI to provide a number of tasks for the Chassahowitzka River/Estuary System. These include the development of a three dimensional hydrodynamic model with salinity and temperature state variables. DSI were also tasked to determine of the areas in the Chassahowitzka system that meet manatee habitat criteria during critical conditions. Finally, the study sought to simulate salinity impacts and the resulting changes in the volume, area and shoreline lengths of salinity regimes due to reductions in spring flows due to groundwater extractions and climate change.

Project Goal

DSI under the direction of SWFWMD, conducted a data assessment and statistical regression for missing data periods, calculated the joint probability analysis to establish the baseline critical condition of MFL for providing adequate protection to the manatee refuge.

Chassahowitzka River and Estuary, Florida


The 3D hydrodynamic (salinity and temperature) model was calibrated using USGS stations along the river’s centerline. This model was then used to develop the minimum baseline refuge areas/volumes and determine the changes in salinity regimes due to reductions in spring discharges.