Quick Answer
If the water table drops, a well may still be usable but its depth and yield will likely decrease, requiring adjustments to the well's design or operation to maintain access to water.
Assessing a Dropping Water Table
A dropping water table indicates a decrease in groundwater recharge or an increased rate of groundwater discharge, often due to drought, over-extraction, or changes in local hydrology. To determine if a well remains viable, measure the water level at the well and compare it to historical data. If the water level has dropped significantly, re-evaluate the well’s depth, casing, and screen to ensure they are adequate for the new water level.
Maintaining a Functional Well in a Dropping Water Table Scenario
To maintain access to water in a dropping water table scenario, consider the following adjustments:
- Deepen the well: If the water table drops below the current well screen, deepen the well to regain contact with the water table.
- Adjust the well screen: If deepening is not feasible, adjust the well screen to a shallower depth to capture the remaining water table.
- Implement a pumping system: Install a submersible pump or a jet pump to increase the well’s yield and reduce the impact of a dropping water table.
Monitoring and Maintenance
Regular monitoring of the well’s water level and yield is crucial in a dropping water table scenario. Track changes in the water level and adjust the well’s operation accordingly. Regular maintenance, including cleaning the well screen and inspecting the casing, will also help maintain the well’s integrity and ensure continued access to water.
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