Faherty Lake
Cass County, MinnesotaView mapDirections
Minnesota PCA publishes the water-quality measurements for Faherty Lake. Here is what has been measured.
- Eutrophic
- Public access
- Limited data
Faherty Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 26.5 µg/L. Chlorophyll-a (algae): 10.7 µg/L.
Faherty Lake is a productive, nutrient-rich eutrophic lake in Cass County, Minnesota. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 103 other monitored lakes in Cass County, Faherty Lake ranks #92 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-10-20. 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 Faherty Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Faherty Lake
These are the measurements Minnesota PCA publishes for Faherty Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 6.2 ft. Phosphorus 26.5 µg/L. Chlorophyll-a 10.7 µg/L. TSI 52.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 6.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 26.5µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 10.7µg/L | Fair GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 52 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Faherty Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Faherty Lake typically sits around 57°F at the surface in October. Summer average is about 65°F. Usually warmest in Aug (about 68°F) and coldest in May (about 52°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (52°F) to its warmest (68°F).
Typical surface water temperature by month, from 328 field readings (2021–2021) via the EPA Water Quality Portal. See the full Faherty Lake water temperature breakdown →
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Faherty Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Aquatic Plant Report — Faherty (1633)Aquatic Plant Report · MN DNR LakeFinder
Stays via Stay22
Stays near Faherty Lake
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Fishing Faherty Lake
Water quality readings over time
3 seasons of samples on record (2021–2024). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Improving-3.96 µg/L/yr3 years
Chlorophyll-a
Improving-1.32 µg/L/yr3 years
Reservoir Info (USACE NID)
Faherty Lake is a man-made reservoir impounded by the Highland Creek (completed 1970), built primarily for other on the Highland Creek; earth-type dam, 11 ft tall and 320 ft long.
- Normal storage
- 62 ac-ft
- Max storage
- 232 ac-ft
- Drainage area
- 0.6 sq mi
- Hazard class
- Low
- Owner
- USDA FS
Source: USACE National Inventory of Dams, NID ID MN00648 · Operator website · Matched by proximity (0.71 km)
Nearby Lakes in Cass County
Frequently asked questions about Faherty Lake
Where is Faherty Lake?
- Faherty Lake is a lake in Cass County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Faherty Lake?
- Faherty Lake in Cass County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 6.2 ft visibility. Phosphorus: 26.5 µg/L. Chlorophyll-a (algae): 10.7 µg/L.
Is Faherty Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Faherty Lake?
- Faherty Lake typically sits around 57°F at the surface in October, from 328 EPA Water Quality Portal field readings (2021–2021). That is a typical value for the month, not a live reading.
Can I fish at Faherty Lake?
- Public access to Faherty Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Faherty Lake across LakeQuality
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Where this data comes from
67 measurements from 1 monitoring station, 2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Leech Lake Band of Ojibwe
LEECHLAK_WQX67 samples · 2021
Analytical methods
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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.