AQUELIA JOURNAL / MIAMI · SOUTH FLORIDA
Miami’s Biscayne Aquifer: what the saltwater map shows.
A USGS map makes an invisible boundary easier to understand. Its measurements describe groundwater changes over time and require a different reading from a tap-water report.
USGS map ·
Read the map’s date first
The USGS publication released on 8 December 2025 maps the approximate inland extent of saltwater at the aquifer’s base in 2022. Its publication year and the year represented by the map are different. That distinction matters when an older measurement appears in a recent headline.[1]
The coastline does not move as one
Compared with 2018, the study found inland movement in northern and southern areas, with relatively little change in the east-central area. Reported advances reached 0.3 kilometre in the north and 0.8 kilometre in the southern Model Land Area. These are location-specific changes, not a uniform countywide rate.[1]
Connect the aquifer to everyday decisions
Miami-Dade identifies the Biscayne Aquifer as its primary drinking-water source and links conservation with preserving that resource. For a property assessment, keep this regional map separate from the supplier’s treatment and sampling records. A mapped boundary cannot establish a concentration at a particular household tap or determine which equipment a building needs.[1][2]
The key to reading it
Use groundwater maps to understand the source and utility reports to understand supplied water. Both are valuable when their geography and dates remain visible.
EVIDENCE YOU CAN CHECK
Sources and documents.
- 01
U.S. Geological Survey
Approximate inland extent of saltwater intrusion at the base of the Biscayne aquifer, Miami-Dade County, Florida, 2022Scientific Investigations Map 3541 · first posted 2025-12-08 · comparison of 2018 and 2022 - 02
Miami-Dade County
Saltwater IntrusionBiscayne Aquifer, conservation and saltwater intrusion · accessed 2026-09-15
Sources consulted on September 15, 2026. Original writing and translation. Data is attributed to its publishers and does not establish the performance of Aquelia equipment.