Sugarloaf Lake
Washtenaw County, Michigan280 acresView mapDirections
EGLE publishes the water-quality measurements for Sugarloaf Lake. Here is what has been measured.
- Oligotrophic
- 10 ft max depth
- Public access
- Limited data
Sugarloaf Lake in Washtenaw County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 9.5 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 10 ft. Surface area: 280 acres.
Free interactive depth-contour map of Sugarloaf Lake, reaching a maximum surveyed depth of 10 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Michigan DNR.
Sugarloaf Lake is a 280-acre cold, clear oligotrophic lake in Washtenaw County, Michigan with a maximum depth of 10 feet. Overall water quality is improving over recent sampling years. The lake supports 2 documented fish species including Northern pike and Spotted gar. Public access is available. Compared to the 7 other monitored lakes in Washtenaw County, Sugarloaf Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2023-09-24. Methodology: how these readings are compared.
Swimming conditions
Readings onlyLimited data
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Sugarloaf Lake is safe to swim in today is a call for the Michigan Department of Environment, Great Lakes, and Energy (EGLE) and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Sugarloaf Lake
These are the measurements EGLE publishes for Sugarloaf Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 9.5 ft. Phosphorus 10 µg/L. Chlorophyll-a 1.9 µg/L. TSI 40.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 10µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 1.9µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 40 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Sugarloaf Lake
Answers come straight from the public measurements and survey records on this page.
Lake Details
Max depth
10 ft
Surface area
280 acres
Public access
Yes
Listed by EGLE
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Stays near Sugarloaf Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Sugarloaf Lake
Water quality readings over time
2 seasons of samples on record (2022–2023). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Phosphorus
Improving-6 µg/L/yr2 years
Reservoir Info (USACE NID)
Sugarloaf Lake is a man-made reservoir impounded by the Winnewana Dam (completed 1956), built primarily for recreation on the Tributary to Portage River; earth-type dam, 12 ft tall and 270 ft long.
- Surface area
- 280 ac
- Normal storage
- 1,000 ac-ft
- Max storage
- 1,560 ac-ft
- Drainage area
- 1.8 sq mi
- Hazard class
- Significant
- Owner
- MDNR Parks & Recreation
Source: USACE National Inventory of Dams, NID ID MI00327 · Operator website · Matched by proximity (0.8 km)
Nearby Lakes in Washtenaw County
Frequently asked questions about Sugarloaf Lake
Where is Sugarloaf Lake?
- Sugarloaf Lake is a lake in Washtenaw County, Michigan. Its water-quality measurements are published by EGLE and shown on this page as reported.
What is the water quality of Sugarloaf Lake?
- Sugarloaf Lake in Washtenaw County, Michigan has water-quality measurements published by EGLE, shown here as reported. Water clarity: 9.5 ft visibility. Phosphorus: 10 µg/L. Chlorophyll-a (algae): 1.9 µg/L. Maximum depth: 10 ft. Surface area: 280 acres.
Is Sugarloaf Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Sugarloaf Lake?
- Sugarloaf Lake has a maximum depth of 10 feet. The lake covers 280 acres.
What fish are in Sugarloaf Lake?
- Fish species found in Sugarloaf Lake include Northern pike, Spotted gar. Sugarloaf Lake is located in Washtenaw County, Michigan.
Can I fish at Sugarloaf Lake?
- Public access to Sugarloaf Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Michigan's fish and wildlife agency, so check its current regulations before you go.
Explore Sugarloaf Lake across LakeQuality
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Fish species and the cleanest lakes across Michigan
Fish species and best lakes in Washtenaw County
Species activity outlook by water temperature and season
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Michigan's cleanest lakes, ranked on agency measurements
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Where this data comes from
26 measurements from 1 monitoring station, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- Michigan EGLE - MiCorps
21MICH_MICORPS26 samples · 2022–2023
Analytical methods
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.