Triangle Lake
Livingston County, Michigan53 acresView mapDirections
Not enough samples to grade — the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. No letter yet. Here is what we do have.
- 43 ft max depth
- Limited data
Triangle Lake in Livingston County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 9.5 ft visibility. Phosphorus: 24.5 µg/L. Surface area: 53.2 acres.
- Clarity
- 9.5 ft
- Typical in September
- 70°F
- Max depth
- ~43 ft est.
- Area
- 53 acres
- Phosphorus
- 24.5 µg/L
- Trend
- ↑ Improving
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Watch Triangle Lake’s letter
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Why Triangle Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Triangle Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity and phosphorus, but not algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by EGLE and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Triangle Lake is a 53-acre lake in Livingston County, Michigan with an estimated average depth of about 43 feet. Overall water quality is improving over recent sampling years.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2023-09-18. 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 Triangle Lake
These readings exist but are not enough for an A–F grade — see why.
Moderate clarity, visible to about 9.5 ft. Phosphorus 24.5 µg/L. TSI 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 9.5 ft | Not graded |
| Phosphorus | 24.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Water Temperature
Triangle Lake typically sits around 70°F at the surface in September. Summer average is about 71°F. Usually warmest in Aug (about 74°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 366 field readings (2010–2014) via the EPA Water Quality Portal. See the full Triangle Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~43 ft est. |
| Average Depth | ~10 ft est. |
| Surface Area | 53 acres |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Michigan has not published bathymetry for Triangle 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 Triangle Lake
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↑ Improving | -0.5 µg/L/yr | 2 |
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Triangle Lake under Clean Water Act (NPDES) discharge permits.
- Marion TownshipHowell · 0.8 mi away · NPDES MIG610198
- D & J Gravel Co Inc-Plant IiHowell · 1.5 mi away · NPDES MIG490234
- Lakeland Montessori SchoolLakeland · 2.5 mi away · NPDES MIG081085
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 Triangle Lake
Triangle Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Livingston County
Frequently asked questions about Triangle Lake
Where is Triangle Lake?
- Triangle Lake is a lake in Livingston County, Michigan. LakeQuality has not rated this lake (UNRATED) — the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity.
What is the water quality grade for Triangle Lake?
- Triangle Lake in Livingston County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 9.5 ft visibility. Phosphorus: 24.5 µg/L. Surface area: 53.2 acres.
Is Triangle Lake safe to swim in?
- The letter is not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Triangle Lake?
- Triangle Lake typically sits around 70°F at the surface in September, from 366 EPA Water Quality Portal field readings (2010–2014). That is a typical value for the month, not a live reading.
How deep is Triangle Lake?
- No published bathymetric survey covers Triangle Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 43 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 53.2 acres.
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Where this data comes from
15 measurements from 1 monitoring station, 2021–2023. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Michigan EGLE - MiCorps
21MICH_MICORPS15 samples · 2021–2023
Analytical methods
- Phosphorus by Colorimetry
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)