Amherst Millpond
Portage County, WisconsinLimited DataEutrophic
Amherst Millpond sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. At only 7 ft deep, Amherst Millpond is shallow — wind keeps the water column mixed and sediment resuspension drives phosphorus levels harder to manage. Amherst Millpond is small — 38 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Amherst Millpond ranks 22 of 28 in Portage County — at the lower end of the locally monitored distribution.
An invasive species record — Banded Mystery Snail — has been logged at Amherst Millpond; Wisconsin DNR maintains the official infested-waters list. The lake's fish records list 2 species — a varied community without one dominant gamefish. Public access is available — the lake is on the Wisconsin DNR public-access list. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2021-08-22. Grade methodology: LakeGrade methodology.
Watch Amherst Millpond water quality
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Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
No clarity data. Phosphorus level: 31.3 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | 31.3 µg/L | C |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 7 ft |
| Surface Area | 38 acres |
| Public Access | Yes |
Fish Species
Click a species to see every graded lake where it is documented.
→ Best fishing times for Amherst Millpond (14-day solunar calendar)
→ Is it safe to eat fish from Amherst Millpond? (mercury & PFAS guide)
→ Amherst Millpond fishing regulations (limits, seasons, special rules)
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Phosphorus | ↑ Improving | -2.6 µg/L/yr | 2 |
Recreation & Access
Location
County Ranking
Ranked #22 of 28 lakes in Portage County
Cleaner Lakes Within 30 Miles
Amherst Millpond holds Grade C. 3 nearby lakes hold higher grades.
Nearby Lakes in Portage County
More Wisconsin Lake Rankings
State Parks Near Amherst Millpond
Other Grade C Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. 4 stations on file (most recent sample 2021).
Fish Species (DNR-rated)
Reservoir Info (USACE NID)
Amherst Millpond is a man-made reservoir impounded by the Amherst (completed 1857), built primarily for recreation on the Waupaca (Tomorrow) River; gravity-type dam, 14 ft tall and 370 ft long.
- Surface area
- 48 ac
- Normal storage
- 116 ac-ft
- Max storage
- 260 ac-ft
- Drainage area
- 90 sq mi
- Hazard class
- Significant
- Owner
- Renew Hydro Power, LLC;Village of Amherst
All listed purposes: Recreation;Hydroelectric.
Source: USACE National Inventory of Dams, NID ID WI00286 · Operator website · Matched by proximity (0.66 km)
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Fish and recreation data from Wisconsin DNR Lakes
Public boat-access points from the USGS National Boat Ramps inventory
Most recent sample: 2021-08-22
Monitoring stations: 1
Where to stay near Amherst Millpond
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