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Illinois Water Assets

Midwest

Illinois draws from deep sandstone aquifers, glacial drift aquifers, and the extensive alluvial aquifers along the Illinois and Mississippi rivers.

Reasonable Use100 counties tracked2448 active alerts
121,392
Total Assets
54.5
Avg WIS
54,304
Verified
2
High WIS (75+)

Illinois Water Intelligence Report

Hi3 Water tracks 121,392 water assets across Illinois, spanning 100 counties and 7 distinct asset types. The average Water Intelligence Score (WIS) across Illinois is 54.5/100, with 2 assets scoring in the high-value range (75+). Illinois operates under Reasonable Use water law, which directly affects water rights acquisition and asset valuation in this state.

The dominant water asset type in Illinois is Well (67,078 assets, avg WIS 47.4). The highest concentration is in Cook County with 1,329 tracked assets.

2,448 active regulatory alerts are currently tracked in Illinois, including EPA violations, drought declarations, and state water board enforcement actions. Always check the regulatory intelligence for any asset before making acquisition decisions.

Data sources: USGS Water Data, EPA ECHO, state water boards, and verified field reports. Water Intelligence Scores are computed across flow rate, geological stability, legal accessibility, sustainability, and rarity. Report last updated: October 16, 2026.

Asset Types in Illinois

Intelligence Grade Distribution

How Illinois assets are graded

S (≥90) — Exceptional0 (0.0%)
A (75-89) — Excellent2 (0.0%)
B (55-74) — Good50,503 (41.6%)
C (35-54) — Fair70,887 (58.4%)
D (<35) — Limited0 (0.0%)

Regulatory Alerts

Drought, EPA violations, and enforcement actions affecting Illinois

82
critical
125
high
2101
medium
140
low
0
info
Hazardous Waste Facility: Grafsolve Co
epa_rcra · hazardous_waste
Hazardous Waste Facility: Waukegan High School West
epa_rcra · hazardous_waste
Hazardous Waste Facility: Epic Circuits Inc
epa_rcra · hazardous_waste

Top Counties in Illinois

Cook
1,329 assetsWIS 42
Champaign
1,091 assetsWIS 41
Will
888 assetsWIS 42
Kane
864 assetsWIS 44
Lake
850 assetsWIS 42
McLean
718 assetsWIS 41
DuPage
691 assetsWIS 42
Kankakee
607 assetsWIS 41
McHenry
587 assetsWIS 43
Vermilion
429 assetsWIS 41
Iroquois
408 assetsWIS 41
Tazewell
403 assetsWIS 42

Aquifer Type Mix

confined
648
Avg WIS 53
unconfined
641
Avg WIS 44
fossil
1
Avg WIS 77

Top 10 Water Assets in Illinois

Ranked by Water Intelligence Score — Illinois's highest-scoring springs, wells, and aquifers.

View all on map
  1. 1

    Mahomet Aquifer — Central Illinois

    Aquifer
    Champaign County·1,000 GPM
    79
    WIS
  2. 2

    Cambrian-Ordovician Fossil Aquifer — Northern Illinois

    Fossil Water
    Kane County·300 GPM
    77
    WIS
  3. 3

    Duck Creek Station Dams

    Reservoir
    ·1,229,797 GPM
    67
    WIS
  4. 4

    Shelbyville Dam

    Reservoir
    ·50,000,000 GPM
    67
    WIS
  5. 5

    American Coal/Galatia/Bunkhouse Rdf Dam

    Reservoir
    ·7,181 GPM
    67
    WIS
  6. 6

    Coffeen Gmf Gypsum Stack Dam

    Reservoir
    ·493,714 GPM
    67
    WIS
  7. 7

    Camp Saukenauk Lake Dam

    Reservoir
    ·493,714 GPM
    66
    WIS
  8. 8

    Lake In The Hills Dam 1

    Reservoir
    ·6,283,634 GPM
    66
    WIS
  9. 9

    Holiday Lake Dam

    Reservoir
    ·13,725,252 GPM
    66
    WIS
  10. 10

    Condit Dam 1

    Reservoir
    ·44,883 GPM
    66
    WIS
Avg Flow Rate
1,374,392 GPM
Avg Depth
196 ft
For Sale
0
Fossil Water
1

Explore Illinois on the Interactive Map

View all 121,392 water assets, aquifer boundaries, water rights data, and regulatory alerts for Illinois.