Broward County is located in southeast Florida. It is the seventh-largest county in the state and ranks number two in population. As shown in the figure below, the western two-thirds of Broward County is entirely undeveloped as part of the Everglades Water Conservation area. A protective levee runs north to south in order to hold the water four feet higher in the west portion of the county.

Map of Broward County, Florida

Land development began in the 1920s. Canals, originally constructed for drainage and flood control, allowed for extensive urban development.

Growth of Broward County from 1920's to present-day.

Broward County’s main source of water comes from the Biscayne Aquifer (figure below), one of the most productive aquifers in the world. It provides nearly 1 billion gallons a day on average. The Biscayne Aquifer is an unconfined coastal aquifer, which means it is heavily recharged from the surface and rainfall and is also influenced by the coastal boundary with the Atlantic Ocean. Because it is highly permeable and lies at shallow depths, it is vulnerable and readily susceptible to contamination. Water quality pressures exist from the urban environment and from the ocean.

The Biscayne aquifer.

The figure below demonstrates the strong level of integration in Broward’s water system. Biscayne aquifer is very shallow and sits just a few feet below ground in most parts of the county. Canals are an important feature, connecting to groundwater and providing direct recharge, as well as flood protection and control of saltwater intrusion. The wellfields must be maintained in the fresh portion of the system, which is becoming more difficult as sea level rises. Withdrawals and recharge are carefully managed to protect wells from saltwater contamination. We also seek to Maintenance of groundwater elevations, mostly through the canal system operation, is imperative to prevent seepage from the Everglades, since the amount of water we can extract from the Everglades is limited.

Water system integration in Broward County.

Water systems stressors include:

• Human-induced Stresses:
  • Urban Development
  • Wellfield pumping
  • Canal water level management
  • Everglades Drainage
  • Agricultural Needs
  • Lake Okeechobee Regulation Schedules
• Natural Stresses (and Climate Change):
  • Sea level rise
  • Extreme events

Broward County has many water managers, including twenty-five water providers, fifteen sewer providers, and over twenty control/drainage districts managing stormwater. Coordination among all those actors is essential for the optimization of our water system and managing in a more productive way.

Here is a list of some of the primary water policies driving decision-making in Broward County:

• 1972 – Land and Water Management Act (Areas of CriticalState Concern) and Florida Water Resources Act
• 1985 – Growth Management Act (+ later amendments)
  • Water Supply Facility Work Plans
• 2002 – Florida Water Conservation Initiative
• 2007 – Regional Water Availability Rule
  • Alternative Water Supply
• 2008 – Ocean Outfall Legislation
  • Mandated Beneficial Reuse
• 2011 – Numeric Nutrient Criteria
  • Stricter water quality protections

In 2017, Broward County Commissioners approved The Future Conditions map series to use in establishing regulatory criteria based on modern design standards that account for future climate conditions. A sample from the series is shown below.

Broward County future conditions map series.

The Future Average Wet Season Groundwater Elevation Map (upper right corner in the previous figure) depicts groundwater elevation. It sets minimal drainage requirements for major developments and new developments in the county based on data showing rising groundwater levels in the county will cause reduced soil storage.

Future Conditions Flood Elevation graphic (figure below)  is currently being developed, and will establish minimal finish for elevations in the county. Every year, the FEMA maps show higher elevations, indicating a need to create a progressive map that anticipates future flood elevations.

Future conditions flood elevation guide.

• Mapping Future Floodplains
  • Increased rainfall due to warming climate
  • Year 2060-2069 sea level rise
  • Increased runoff due to higher water tables
  • Land use changes
  • Accomplished through integrated GW/SW modeling
• Will enhance infrastructure resilience 
  • Regulatory purpose
  • Finished floor elevations, streets, sanitary manholes, etc.

Future conditions flood elevation map.

Future rainfall is challenging to predict. The future reveals a large range of possibilities. Part of our study is evaluating those data sets.

Develop Rainfall Data Set (options under evaluation) 

• Use NOAA Atlas 14 data
• Statistically downscaled localized constructed analogs (LOCA)
• Dynamically downscaled data from COAPS
• Hyperion Group Data
• Probabilistic Approach

Other Considerations

• Future average GW levels from BC MODFLOW models
• Future Land Use
• Future Structure Operations Planned Infrastructure Improvements
• No storm surge (FEMA Coastal Zone A)
• No joint probabilistic distribution analysis