Illinois Well Data · ISGS
ISGS well records, searchable by address
Every Illinois well log is filed with the Illinois State Geological Survey water well records. Those records are public, but they are organized by mapped location and record number — not by street address. We hold 307,537 of them and rebuild the index weekly, so you can start from an address instead.
✓ Verified against ISGS · 2026-08-20
Enter any Illinois address and we return the wells recorded around it — every Illinois water well record carries a mapped location, but the state files wells by section and township rather than by street address, so results show the records around a property rather than a single wellhead.
Free address lookup Full property report — $29What a ISGS record contains
Not every filed report carries every field — older records are thinner, and what the state captured changed over the decades. This is the real coverage across all 307,537 records, so you know what to expect before you search.
| Field | What it tells you | Records with it | Coverage |
|---|---|---|---|
| Original log document | A direct link to the ISGS copy of the filed log itself. | 307,537 (100%) | |
| Mapped location | Coordinates, so the log can be found by address instead of by record number. | 307,521 (100%) | |
| Total depth | How deep the hole was drilled, in feet. | 301,997 (98%) | |
| Date completed | When the well was finished and the log filed. | 289,449 (94%) | |
| Driller | The licensed company that drilled the well and signed the log. | 282,111 (92%) | |
| Tested yield | Gallons per minute the well produced on the driller’s pump test. | 172,029 (56%) |
How this differs from going to ISGS directly
Nothing here replaces the official record, and for a single well you already have the record number for, ISGS is the place to go (isgs.illinois.edu/groundwater/well-records). What this site adds is the part that is hard from the source data:
- An address is enough. You do not need a record number, a section-township-range, or a latitude to start. Every Illinois water well record carries a mapped location, but the state files wells by section and township rather than by street address, so results show the records around a property rather than a single wellhead.
- The neighbours, not just the well. Buyers and lenders care what depth and yield are normal nearby, which means reading many records at once, not one.
- The same statistics everywhere. Median depth, static water level and yield are computed identically in every county, so two counties can actually be compared. The exact filters are on the methodology page.
- The original is always one click away. 307,537 of our records carry a direct link to the ISGS copy of the filed log itself.
ISGS records by county
See all 102 Illinois counties → · What a Illinois well log contains →
Common questions
With ISGS — the Illinois State Geological Survey water well records. Every Illinois driller files a completion report there for each well drilled, and that filing is the authoritative copy of the record. The official site is isgs.illinois.edu/groundwater/well-records.
Not directly — well records are filed against a mapped location and a record number, not a mailing address, which is the single most common reason people give up on the search. That is exactly the gap this site fills: enter an address on our free lookup and we return the recorded wells around that point, every Illinois water well record carries a mapped location, but the state files wells by section and township rather than by street address, so results show the records around a property rather than a single wellhead.
No, and it is not meant to be. This is an independent index built from the data ISGS publishes, rebuilt weekly. Every well we show links back to its own ISGS record, so you can always open the original filed log. If our copy and the state's ever disagree, the state's is right.
Our current copy holds 307,537 records across 102 counties, with completion dates from 1850 to 2026. That is everything ISGS publishes in its bulk record set as of 2026-08-20. Wells drilled before the state's filing requirement — and hand-dug or unpermitted wells — were never filed anywhere, so they are in neither copy.
Searching by address here is free, the same as searching ISGS is free. What we charge for is the compiled property report — every recorded well near one address, with the statistics and the original log links, as one printable document for a sale or a loan file. That is $29.
The property report pulls every recorded well near an address — depths, water levels, yields, drillers , and links to each original filed log — as one printable summary for due diligence.
Property report — $29Driller, agent, or inspector pulling these regularly? Unlimited & white-label plans →