Crabtree Lake
Cook County, IllinoisView mapDirections
Not Rated: one monitoring station are on record, but they measured water clarity only. LakeQuality’s A–F method grades total phosphorus, total nitrogen, chlorophyll-a, and turbidity; clarity is shown, not scored.
- 30 ft max depth
- Limited data
Crabtree Lake in Cook County, Illinois is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2 ft visibility.
- Clarity
- 2 ft
- Max depth
- ~30 ft est.
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Watch Crabtree Lake’s letter
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Why Crabtree Lake has no grade
Crabtree Lake has monitoring on record from one station, but only water clarity was measured. LakeQuality’s A–F letter uses total phosphorus, total nitrogen, chlorophyll-a, and turbidity against EPA National Lakes Assessment condition classes. With none of those grading measurements on record, Crabtree Lake is Not Rated — not an F. Its 2-foot median from 1 readings collected 2022 is still shown as clarity, but clarity alone cannot earn a letter.
Not Rated is EPA Integrated Reporting Category 3 — insufficient information. Everything below that has been measured is still reported on this page.
Sampling is run by Illinois EPA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Crabtree Lake is a lake in Cook County, Illinois with an estimated average depth of about 30 feet.
Source: EPA Water Quality Portal sampling records, Illinois EPA, last sampled 2022-09-28. Grade methodology: LakeQuality methodology.
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Check local advisories before you swim.
Water quality measurements for Crabtree Lake
These readings exist but are not enough for an A–F grade — see why.
Very murky, less than 2 ft of visibility. TSI 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~30 ft est. |
| Average Depth | ~7 ft est. |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Illinois has not published bathymetry for Crabtree Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Crabtree Lake
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.
Graded lakes near Crabtree Lake
Crabtree Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Cook County
Frequently asked questions about Crabtree Lake
Where is Crabtree Lake?
- Crabtree Lake is a lake in Cook County, Illinois. LakeQuality has not rated this lake (UNRATED) — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
What is the water quality grade for Crabtree Lake?
- Crabtree Lake in Cook County, Illinois is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2 ft visibility.
Is Crabtree Lake safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
How deep is Crabtree Lake?
- No published bathymetric survey covers Crabtree Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 30 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Crabtree Lake across LakeQuality
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Where this data comes from
1 measurement from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- USGS Illinois Water Science Center
USGS-IL1 sample · 2022
Analytical methods
- Secchi disk method
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)