A domestic well on two acres and a 1,000 gpm municipal well draw on the same physics: a static water level, a drawdown when pumping, a pump with a curve, a screen that plugs. What differs is the scale, the instruments, the legal obligations and what a mistake costs. If you own a private well, here is what carries over from the municipal world and what does not.
What is the same
- Specific capacity still tells you whether the well is plugging. A domestic well that used to recover in an hour and now takes three is telling you its specific capacity has fallen. What caused it — plugging, a dropping water table, a pump losing its impellers — is the same short list a district works through, and settling which one it is takes the same evidence: a measured test, and a look down the hole.
- Pump efficiency still sets your electricity bill. A worn submersible pump on a deep well can double the energy per gallon before it fails.
- Construction decides lifespan: the screen and seal on a 1995 domestic well matter exactly as they do on a municipal one, and the driller’s log is worth finding.
- Rehabilitation works on private wells too, and earlier is cheaper for the same reasons.
What is different
| Private / domestic well | Municipal well | |
|---|---|---|
| Metering | Rarely metered; extraction estimated | Metered by source; reported monthly |
| Reporting | Domestic wells using up to about 2 acre-feet a year are generally de minimis under SGMA and outside GSA extraction reporting; some basins still ask for registration | SGMA extraction and elevation data to the GSA; eAR to the Division of Drinking Water; adjudication reports where applicable |
| Water quality | Owner’s responsibility; annual coliform and nitrate testing recommended | Title 22 monitoring schedule under a DDW permit |
| Instruments | Often none beyond a pressure gauge | Flow meter, level transducer, power monitoring, SCADA |
| Cost of failure | A dry tap and a pump replacement | Lost peak capacity for a community, emergency purchases, a regulatory record |
What a private well owner should record
Four things, once or twice a year: the static water level (a sounder or a wetted-tape reading), a pumping level after the pump has run for a while, the approximate flow (a bucket and a stopwatch at the hose bib is honest enough), and the electricity the pump uses if you can read it. Keep the driller’s log, the pump model and the installation date with them. That is a well record, and it is more than most districts had ten years ago.
Where Waterwell IQ fits
Waterwell IQ™ is built for public water agencies and the engineers and contractors who serve them; the membership is per well with unlimited users, which suits a district with forty wells and not a household with one. But the arithmetic is public: the calculator on our home page runs the same wire-to-water and specific-capacity maths for any well, and the methodology page shows every formula. Small mutual water companies and community systems with a handful of wells are welcome; the pricing page explains how.
Run your own well’s numbers now. Open the calculator →
Sources
- California Department of Water Resources. Water Well Standards: State of California, Bulletin 74-81. 1981.
- National Ground Water Association. Water Well Rehabilitation: Private Wells and Public Water Systems. 2016.
- Water Replenishment District of Southern California. Specific Capacity — A Measure of Well Performance, Well Problems, and Aquifer Transmissivity, Technical Bulletin TB02 (Part 1 of 2). 2005. Source for specific capacity as gpm per foot of drawdown, its decline as perforations and filter pack plug, and the 25% decline commonly used as a rehabilitation trigger.
Every link above was retrieved and read on 2026-09-09. Paid standards are named by designation so you can check them against your own copy.