Locke Lake
Anoka County, Minnesota23 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Locke Lake. Here is what has been measured.
- Eutrophic
- Eurasian watermilfoil
- Public access
Locke Lake in Anoka County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 97 µg/L. Chlorophyll-a (algae): 20.9 µg/L. Surface area: 23 acres.
Locke Lake is a 23-acre productive, nutrient-rich eutrophic lake in Anoka County, Minnesota. Phosphorus level is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 22 other monitored lakes in Anoka County, Locke Lake ranks #18 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-07. 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. Check local advisories before you swim.
Whether Locke 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 Locke Lake
These are the measurements Minnesota PCA publishes for Locke 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 3 ft of visibility. Phosphorus 97 µg/L. Chlorophyll-a 20.9 µg/L. TSI 64.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 97µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 20.9µg/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. | 64 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Locke Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Locke Lake typically sits around 67°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 76°F) and coldest in Sep (about 67°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (67°F) to its warmest (76°F).
Typical surface water temperature by month, from 22 field readings (2019–2024) via the EPA Water Quality Portal. See the full Locke Lake water temperature breakdown →
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Locke Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Public Water Access Sites — LockePublic Water Access Sites · MN DNR LakeFinder
Lake Details
Surface area
23 acres
Public access
Yes
Listed by Minnesota PCA
No bathymetric survey has been published for Locke Lake, so its depth is not documented here.
Stays via Stay22
Stays near Locke Lake
Compare lakeside cabins, hotels, and vacation rentals near Locke Lake in Anoka County, Minnesota — 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 Locke Lake are listed below.
Top-rated places to stay near Locke Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
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Fishing Locke Lake
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 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
Stable3 years
Phosphorus
Improving-13.75 µg/L/yr2 years
Chlorophyll-a
Worsening+11.15 µg/L/yr2 years
Reservoir Info (USACE NID)
Locke Lake is a man-made reservoir impounded by the Locke Lake (completed 1956), built primarily for recreation on the Rice Creek; concrete-type dam, 25 ft tall and 100 ft long.
- Surface area
- 23 ac
- Normal storage
- 200 ac-ft
- Max storage
- 320 ac-ft
- Drainage area
- 200 sq mi
- Hazard class
- Significant
- Owner
- City of Fridley
Source: USACE National Inventory of Dams, NID ID MN00396 · Operator website
Nearby Lakes in Anoka County
Frequently asked questions about Locke Lake
Where is Locke Lake?
- Locke Lake is a lake in Anoka County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Locke Lake?
- Locke Lake in Anoka County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 97 µg/L. Chlorophyll-a (algae): 20.9 µg/L. Surface area: 23 acres.
Is Locke 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 Locke Lake?
- Locke Lake typically sits around 67°F at the surface in September, from 22 EPA Water Quality Portal field readings (2019–2024). That is a typical value for the month, not a live reading.
Can I fish at Locke Lake?
- Public access to Locke 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 Locke Lake across LakeQuality
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Where this data comes from
34 measurements from 1 monitoring station, 2021–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA34 samples · 2021–2024
Analytical methods
- Field measurement/observation, generic method
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 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.
Other records on this page
Lake details from Minnesota DNR LakeFinder