Crabtree Lake is a productive, nutrient-rich eutrophic lake in Cook County, Illinois. Water quality is graded F based on 1 sampling years through 2022. Compared to the 67 other monitored lakes in Cook County, Crabtree Lake ranks #49 for water quality.
Source: EPA Water Quality Portal sampling records, Illinois DNR, last sampled 2022-09-28. Grade methodology: LakeGrade methodology.
Watch Crabtree Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 2 ft of visibility. Trophic State Index: 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Crabtree Lake
Compare lakeside cabins, hotels, and vacation rentals near Crabtree Lake in Cook County, Illinois — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Crabtree Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a trip to Crabtree Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Crabtree Lake — straight to your inbox. No spam, unsubscribe anytime.
Planning a whole trip? See where to stay at Illinois’s top lakes →
Fishing Crabtree Lake
Location
County Ranking
Ranked #49 of 68 lakes in Cook County
Cleaner Lakes Within 30 Miles
Crabtree Lake holds Grade F. 2 nearby lakes hold higher grades.
Nearby Lakes in Cook County
Explore Crabtree Lake across LakeGrade
More Illinois Lake Rankings
Other Grade F Lakes in Illinois
Eutrophic Lakes in Illinois
More records, surveys & data sources
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Regulated Pollution Sources Nearby
5 EPA-permitted facilities operate within about 5 miles of Crabtree Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 2 facilities have a reported Clean Water Act violation in the past three years.
- Barrington WwtfBarrington · 3.4 mi away · NPDES IL0021598MajorRecent violation
- Prairie Path Water Port Barrington Shores StpBarrington · 3.4 mi away · NPDES IL0070874Recent violation
- Qtg Development IncBarrington · 2.7 mi away · NPDES IL0001473
- Mj PetroleumBarrington · 3.2 mi away · NPDES IL0077887
- Park Foods, LpBarrington · 4.2 mi away · NPDES IL0005100
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Data Sources
Water quality data from the EPA Water Quality Portal
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Most recent sample: 2022-09-28
Monitoring stations: 1