The depth of the water table in Louisiana is not a single, fixed measurement; it varies significantly across the state, depending on the specific aquifer system and geographical location. Generally, the depth at which groundwater is encountered and accessible for use through wells ranges from less than 100 feet to several hundred feet.
Understanding Water Table Depths Across Louisiana Aquifers
The water table represents the upper surface of the zone of saturation, where the ground is fully saturated with water. While the exact depth of the water table can fluctuate with rainfall and other environmental factors, the depths at which wells are drilled provide a practical indication of where freshwater resources, and thus the water table, are commonly found.
Louisiana is underlain by several vital freshwater aquifer systems, each with distinct characteristics regarding the depth and thickness of their freshwater intervals. The shallowest accessible groundwater, and therefore potentially the shallowest water table, is found in the Southeast Louisiana region.
The following table summarizes the typical range of well depths for major aquifer systems in Louisiana, indicating where groundwater is commonly accessed:
| Aquifer System | Range of Well Depths (feet) |
|---|---|
| SOUTHEAST LOUISIANA | <100 - 3300 |
| EVANGELINE | 200 - 2200 |
| MIOCENE of central Louisiana | 200 - 2200 |
| COCKFIELD | 200 - 900 |
Implications for Groundwater Access
- Southeast Louisiana: In parts of Southeast Louisiana, the water table can be quite shallow, with accessible groundwater found at depths less than 100 feet. This makes groundwater relatively easy to access for various uses.
- Other Major Aquifers: For other significant aquifer systems like the Evangeline, Miocene of central Louisiana, and Cockfield, groundwater is typically encountered starting at depths of 200 feet or more. These systems often extend to much greater depths, providing substantial freshwater reserves.
It is important to note that these "Range of Well Depths" figures indicate where wells are drilled to access the freshwater intervals within these aquifers, which serves as a proxy for the practical depth of the water table and the underlying saturated zone. The actual water table may be shallower than the deepest parts of these well ranges, but these figures illustrate where the bulk of groundwater resources are tapped. For more detailed information on Louisiana's groundwater resources, you can refer to environmental and geological surveys, such as those provided by the Louisiana Department of Environmental Quality.
