How Long Does a Water Well Last?
A water well commonly lasts 25 to 50 years, according to the Minnesota Department of Health, and some last 100 or more. The National Ground Water Association says wells can serve a household for 20 to 30 or more years with proper care.
A well rarely stops working all at once. Its yield falls as the openings that let water in clog with minerals and bacteria, or the casing corrodes, or the water table drops below where the well was built to reach.
Published figures vary by a factor of two, so the table lists each with its source. The pump and pressure tank are a separate question: they wear out sooner and are replaced without redrilling.
Water well lifespan: what each source says
| Source | Figure | Detail |
|---|---|---|
| Minnesota Department of Health | 25 to 50 years is common | Some wells may last 100 or more years |
| National Ground Water Association | 20 to 30 or more years | With proper care; most residential wells are designed to last 20 or more |
| Water Systems Council | 20 to 30 years, or longer | Depends on the quality of materials used in construction |
| Nebraska Extension | Usually about 50 years | Says the life span can vary greatly |
| HomeGuide | 40 or more years | Cost-site figure used in our cost guides |
On casing, University of Missouri Extension says even wells with modern casings that are 30 to 40 years old are subject to corrosion and perforation.
What ends a well's useful life?
- Clogging. The National Ground Water Association says the most common cause of lost flow is plugging of the holes or slots in the casing and encrustation on the well screen, from calcium carbonate, silt, clay, iron sulfides and iron or manganese bacteria.
- Mineral scale. The Water Systems Council and Michigan's environment department both say yield can decline over time as minerals and sediment build up inside the well.
- Casing corrosion. University of Missouri Extension says casings 30 to 40 years old are subject to corrosion and perforation.
- A falling water table. The US Geological Survey says that if groundwater levels decline too far, the owner may have to deepen the well, drill a new one, or at least lower the pump.
Can an old well be restored instead of replaced?
Often, when the problem is clogging. The National Ground Water Association says a professional contractor can often rehabilitate a well and restore enough flow for household or farm needs. Nebraska Extension describes the methods: chemicals to open the well screen, or a surge block.
Michigan's environment department tells new well owners to expect this: over the life of a well, rehabilitation may be needed to improve its performance. Rehabilitation addresses clogging. A water table that has dropped is a different problem, and the US Geological Survey's options for it are lowering the pump, deepening the well or drilling a new one.
How to make a well last longer
The National Ground Water Association says a well should be evaluated every year by a licensed or certified water well professional. Its annual checkup includes a flow test, an equipment inspection, and a water test for coliform bacteria, nitrates and anything of local concern.
The flow test gives you a number to compare from year to year, so a falling yield shows up before the taps do.
Frequently Asked Questions
How long does well casing last?
No source we checked gives a single number. University of Missouri Extension says even wells with modern casings that are 30 to 40 years old are subject to corrosion and perforation, so casing that age is worth having inspected.
Does a well need to be replaced when the water slows down?
Not necessarily. The National Ground Water Association says the most common cause is plugged casing slots and encrusted screens, and that a contractor can often rehabilitate the well and restore flow. If the water table has dropped, the US Geological Survey says the options are lowering the pump, deepening the well or drilling a new one.
How often should a well be inspected?
Every year. The National Ground Water Association says wells should be evaluated annually by a licensed or certified water well systems professional, with a flow test, an equipment check and a water test for coliform bacteria and nitrates.
Does the well pump last as long as the well?
No. The National Ground Water Association says pump systems typically have a shorter lifespan and may need replacement before the well itself. InterNACHI's chart puts a well pump at about 15 years.
Related guides and tools
- Well Inspection & Testing
- How Long Does a Well Pump Last?
- Well Drilling Cost in 2026: Price per Foot & Total New Well Cost
- Well Inspection Cost in 2026: Home-Sale Inspection & Water Test Prices
- No Water From Your Well? Diagnostic Wizard
- Drilled Well vs Dug or Bored Well: Depth, Safety and Cost
- Well Drilling
General information, not a diagnosis of your system. Figures last checked against the sources below on 2026-11-12.
Sources
- Minnesota Department of Health: Finding Lost Wells
- Wellowner.org (NGWA): Water Well Maintenance
- Wellowner.org (NGWA): Annual Water Well Inspection
- Wellowner.org (NGWA): Restoring Flow through Water Well Rehabilitation
- Water Systems Council wellcare: Coping with Low Water Levels
- Nebraska Extension: Private Drinking Water Wells, Operation and Maintenance for Mechanical Components (G2153)
- University of Missouri Extension: Drinking Water Well Management (EQM103F)
- Michigan EGLE: Your New Water Well (revised April 2021)
- US Geological Survey: Groundwater Decline and Depletion
- InterNACHI: Standard Estimated Life Expectancy Chart for Homes
- HomeGuide: Well Pump Replacement Cost (third-party estimate)
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