Fin And Feather Lake
Cerro Gordo County, Iowa16 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Fin And Feather Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · pH / acidity
Fin And Feather Lake in Cerro Gordo County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 2.3 ft visibility. Phosphorus: 112 µg/L. Chlorophyll-a (algae): 42 µg/L. Surface area: 16 acres.
Fin And Feather Lake is a 16-acre highly nutrient-loaded hypereutrophic lake in Cerro Gordo County, Iowa. Overall water quality is declining over recent sampling years. Compared to the 3 other monitored lakes in Cerro Gordo County, Fin And Feather Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2022-09-12. Methodology: how these readings are compared.
Swimming conditions
Readings onlyAlgae risk
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. Fin And Feather Lake is listed impaired under Clean Water Act §303(d) (IR 5) for pH / acidity. Check local advisories before you swim.
Whether Fin And Feather Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Fin And Feather Lake
These are the measurements Iowa DNR publishes for Fin And Feather Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.3 ft of visibility. Phosphorus 112 µg/L. Chlorophyll-a 42 µg/L. TSI 68.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 112µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 42µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 68 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Fin And Feather Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Fin And Feather Lake typically sits around 78°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 78°F) and coldest in Jun (about 72°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (72°F) to its warmest (78°F).
Typical surface water temperature by month, from 9 field readings (2018–2022) via the EPA Water Quality Portal. See the full Fin And Feather Lake water temperature breakdown →
Lake Details
Surface area
16 acres
No bathymetric survey has been published for Fin And Feather Lake, so its depth is not documented here.
Stays via Stay22
Stays near Fin And Feather Lake
Compare lakeside cabins, hotels, and vacation rentals near Fin And Feather Lake in Cerro Gordo County, Iowa — 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Fin And Feather Lake are listed below.
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Fishing Fin And Feather Lake
Water quality readings over time
3 seasons of samples on record (2020–2022). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening3 years
Phosphorus
Worsening+7.95 µg/L/yr3 years
Chlorophyll-a
Worsening+6.1 µg/L/yr3 years
Reservoir Info (USACE NID)
Fin And Feather Lake is a man-made reservoir impounded by the Lake Fin-Feather Dam (completed 1972), built primarily for recreation on the TR-WINNEBAGO RIVER; earth-type dam, 25 ft tall and 1,200 ft long.
- Surface area
- 16 ac
- Normal storage
- 76 ac-ft
- Max storage
- 123 ac-ft
- Drainage area
- 0.22 sq mi
- Hazard class
- Low
- Owner
- Cerro Gordo County Conservation Board
Source: USACE National Inventory of Dams, NID ID IA00175 · Operator website · Matched by proximity (0.05 km)
EPA Impairment Status
Fin And Feather Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Aquatic life.
Source: EPA ATTAINS assessment unit IA 02-WIN-840 · Official waterbody report
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Fin And Feather Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Mason City, City Of StpMason City · 2.9 mi away · NPDES IA0057169MajorRecent violation
- Mason City, City Of WtpMason City · 3 mi away · NPDES IA0077305
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.
Nearby Lakes in Cerro Gordo County
Frequently asked questions about Fin And Feather Lake
Where is Fin And Feather Lake?
- Fin And Feather Lake is a lake in Cerro Gordo County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Fin And Feather Lake?
- Fin And Feather Lake in Cerro Gordo County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 2.3 ft visibility. Phosphorus: 112 µg/L. Chlorophyll-a (algae): 42 µg/L. Surface area: 16 acres.
Is Fin And Feather Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Fin And Feather Lake is listed impaired under Clean Water Act §303(d) (IR 5) for pH / acidity. Check local advisories before you swim.
What is the water temperature of Fin And Feather Lake?
- Fin And Feather Lake typically sits around 78°F at the surface in August, from 9 EPA Water Quality Portal field readings (2018–2022). That is a typical value for the month, not a live reading.
Explore Fin And Feather Lake across LakeQuality
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Where this data comes from
36 measurements from 1 monitoring station, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX36 samples · 2020–2022
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- ISU modification of APHA 2130-B
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)