Portage Lake
Portage Lake in Jackson County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.8 ft visibility. Maximum depth: 40 ft. Surface area: 400 acres.
- Clarity
- 8.8 ft
- Max depth
- 40 ft
- Area
- 400 acres
- Trend
- ↑ Improving
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Why Portage 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 Portage 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, but not phosphorus and 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.
Portage Lake is a 400-acre lake in Jackson County, Michigan with a maximum depth of 40 feet. Overall water quality is improving over recent sampling years. The lake supports 34 documented fish species including Blackstripe topminnow, Bluegill, and Bluntnose minnow.
Source: EPA Water Quality Portal sampling records, EGLE, last sampled 2019-09-20. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Portage Lake
These readings exist but are not enough for an A–F grade — see why.
Moderate clarity, visible to about 8.8 ft. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.8 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Portage Lake
Compare lakeside cabins, hotels, and vacation rentals near Portage Lake in Jackson County, Michigan — 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 Portage Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 40 ft |
| Surface Area | 400 acres |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Portage Lake
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.43 m/yr | 2 |
| Phosphorus | ↑ Improving | -4 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Portage Lake is a man-made reservoir impounded by the Portage Lake Dam (completed 1957), built primarily for recreation on the Tributary to Portage River; earth-type dam, 8 ft tall and 3,200 ft long.
- Surface area
- 400 ac
- Normal storage
- 5,000 ac-ft
- Max storage
- 6,500 ac-ft
- Drainage area
- 4.73 sq mi
- Hazard class
- Low
- Owner
- MDNR Parks & Recreation
Source: USACE National Inventory of Dams, NID ID MI00733 · Operator website
EPA Impairment Status
Portage Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MI040500040204-03 · Official waterbody report
Graded lakes near Portage Lake
Portage Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Jackson County
Frequently asked questions about Portage Lake
Where is Portage Lake?
- Portage Lake is a lake in Jackson 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 Portage Lake?
- Portage Lake in Jackson County, Michigan is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8.8 ft visibility. Maximum depth: 40 ft. Surface area: 400 acres.
Is Portage Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Portage Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Portage Lake?
- Portage Lake has a maximum depth of 40 feet. The lake covers 400 acres.
What fish are in Portage Lake?
- Fish species found in Portage Lake include Blackstripe topminnow, Bluegill, Bluntnose minnow, Bowfin, Brindled madtom, Brook silverside, Brown bullhead, Chestnut lamprey, Common carp, Common shiner, Grass pickerel, Green sunfish, Johnny darter, Lake herring, Lake sturgeon, Lake whitefish, Largemouth bass, Longnose gar, Northern logperch, Northern pike, Pumpkinseed, Rainbow darter, Rock bass, Round whitefish, Sauger, Shorthead redhorse, Silver lamprey, Striped shiner, Walleye, Warmouth, Western banded killifish, White sucker, Yellow bullhead, Yellow perch. Portage Lake is located in Jackson County, Michigan.
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Where this data comes from
27 measurements from 1 monitoring station, 2018–2019. Retrieved from the EPA Water Quality Portal on 2026-08-26.
Collected and reported by
- North American Lake Management Society
NALMS27 samples · 2018–2019
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)