Thiensville Millpond
Ozaukee County, Wisconsin45 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Thiensville Millpond. Here is what has been measured.
- Public access
- Limited data
Thiensville Millpond in Ozaukee County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Phosphorus: 166 µg/L. Surface area: 45 acres.
Thiensville Millpond is a 45-acre lake in Ozaukee County, Wisconsin. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-08-19. Methodology: how these readings are compared.
What Thiensville Millpond is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Thiensville Millpond is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Thiensville Millpond
These are the measurements Wisconsin DNR publishes for Thiensville Millpond, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
No clarity data. Phosphorus 166 µg/L. TSI 78.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | No reading How deep a black-and-white disk stays visible from the surface. Higher is clearer. | |
| Total phosphorus | 166µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 78 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Thiensville Millpond
Answers come straight from the public measurements and survey records on this page.
Lake Details
Surface area
45 acres
Public access
Yes
Listed by Wisconsin DNR
No bathymetric survey has been published for Thiensville Millpond, so its depth is not documented here.
Recreation & Access
- ThiensvillePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
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Fishing Thiensville Millpond
Reservoir Info (USACE NID)
Thiensville Millpond is a man-made reservoir impounded by the Thiensville (completed 1842), built primarily for recreation on the MILWAUKEE; gravity-type dam, 13 ft tall and 370 ft long.
- Surface area
- 45 ac
- Normal storage
- 700 ac-ft
- Max storage
- 2,200 ac-ft
- Drainage area
- 594 sq mi
- Hazard class
- Low
- Owner
- City of Mequon
Source: USACE National Inventory of Dams, NID ID WI00539 · Operator website · Matched by proximity (0.09 km)
Nearby Lakes in Ozaukee County
Frequently asked questions about Thiensville Millpond
Where is Thiensville Millpond?
- Thiensville Millpond is a lake in Ozaukee County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Thiensville Millpond?
- Thiensville Millpond in Ozaukee County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Phosphorus: 166 µg/L. Surface area: 45 acres.
Is Thiensville Millpond safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Are there boat ramps on Thiensville Millpond?
- Thiensville Millpond has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Thiensville. Public access is listed as yes.
Can I fish at Thiensville Millpond?
- Thiensville Millpond has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Thiensville Millpond across LakeQuality
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Where this data comes from
1 measurement from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX1 sample · 2024
Analytical methods
- Phosphorus by Colorimetry
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.
Other records on this page
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory