Wellfield Protection Areas

In Miami-Dade County, our drinking water is drawn from the Biscayne Aquifer, a freshwater-bearing limestone rock formation underneath our feet. This aquifer allows millions of local residents and visitors the benefits of a clean, accessible and relatively inexpensive source of potable water.

The aquifer is extremely porous and the water table is very close to the surface of the ground, making it vulnerable to pollution. Pollutants that are discharged onto the ground or that occur in surface waters can contaminate the groundwater and be drawn into wells that supply drinking water.

For these reasons, Miami-Dade County oversees programs to protect the Biscayne Aquifer from potential sources of contamination.

To reduce the risk of pollution and the cost of treatment of public water supply, the County works with industry, business and homeowners, especially in specific areas around the network of drinking water wellfields know as wellfield protection areas.

The protection areas are designated based on geological characteristics of the aquifer and the flow of water through it. New activities that use or store hazardous materials or generate hazardous waste are prohibited within certain parts of the wellfield protection areas.

There may also be limitations on extent of excavations within a wellfield protection area, or on septic tank specifications and uses.

If you are purchasing a property or propose operating a business in a protection area and intend to use or store hazardous materials, or the property is served by a septic tank or on-site domestic water well, you should call the County to discuss and better understand, any prohibitions, limitations or possible exemptions that apply to the property or business.

You may also search for information concerning the environmental characteristics of properties using the Environmental Considerations GIS tool.

For information on general permitting requirements and land use restrictions in wellfield protection areas, call 305-372-6700.

Wellfields Map
June 16, 2017 Agenda - Wellfield Technical Work Group

In 2015 with the adoption of Ordinance No. 15-25, the Miami-Dade County Board of County Commissioners (BCC) directed the Department of Regulatory and Economic Resources’ Division of Environmental Resources Management (RER-DERM) to conduct additional scientific evaluations of the Northwest and West Wellfield Protection Areas in support of proposed modifications to the boundaries of the Wellfield Protection Areas.

The proposed modifications were based on groundwater modeling conducted by the United States Geological Survey (USGS) as documented in the USGS report (Open-File Report 2013-1086) titled “Estimation of Capture Zones and Drawdown at the Northwest and West Wellfields, Miami-Dade County, Florida, Using an Unconstrained Monte Carlo Analysis: Recent (2004) and Proposed Condition.” In response to the BCC’s directive and to address some of the concerns expressed regarding the USGS groundwater model, DERM convened a Wellfield Technical Working Group (TWG). The group consisted of water resources planners, groundwater/surface water modeling experts, members of the academic/scientific community and stakeholder representatives. The goal of the group was to provide recommendations for addressing the concerns expressed regarding the USGS groundwater model.

The TWG issued a final report in September 2017. The primary recommendation involved assessing an alternative methodology to the USGS groundwater model's approach for estimating travel time contours in wellfield protection areas.

Following the TWG’s recommendation in February 2018, RER-DERM worked in collaboration with Miami-Dade County Water and Sewer Department (WASD) to procure the services of groundwater modeling expert, Groundwater Tek Inc (GTI). GTI was tasked with evaluating and implementing the alternative groundwater modeling approach recommended by the TWG, providing revised travel time for the wellfields based on the model’s outputs.

On May 12, 2025, GTI issued a report titled, “Estimation of Capture Zones and Drawdown at the Northwest and West Wellfields in Miami-Dade County, Florida, Using Monte-Carlo Simulations Based on the USGS 2013 Study.” The report and the proposed revisions to the boundaries of the Northwest and West Wellfield Protection Areas, along with supporting documentation (groundwater model files and shape files) are available. The 60-day public comment period is now open.

Comments must be submitted by the close of business on August 5, 2025 to [email protected]. Questions about this announcement should be directed to [email protected] or [email protected]

A technical workshop will be held within 30 days following the conclusion of the public comment period.

Environmental Considerations GIS

Search the Environmental Considerations GIS Map to find out if a property may have any environmental features associated with it.

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