Deep Lake
Deep Lake in Ramsey County, Minnesota has a water quality grade of C (Fair). Water clarity: 3.9 ft visibility. Phosphorus: 72 µg/L. Chlorophyll-a (algae): 6.3 µg/L. Maximum depth: 11 ft. Surface area: 71.73 acres.
- Clarity
- 3.9 ft
- Typical in August
- 73°F
- Max depth
- 11 ft
- Area
- 72 acres
- Type
- Eutrophic
- Trend
- → Stable
- Public access
- No
Next lake in Ramsey County
Deep Lake is a 72-acre productive, nutrient-rich eutrophic lake in Ramsey County, Minnesota with a maximum depth of 11 feet. Water quality is graded C based on 2 sampling years through 2025. Phosphorus level is declining over recent sampling years. The lake supports 19 documented fish species including bigmouth buffalo, black bullhead, and black crappie. No public access — the lake is private or restricted. Compared to the 43 other monitored lakes in Ramsey County, Deep Lake ranks #12 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-24. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 3.9 ft. Phosphorus level: 72 µg/L. Chlorophyll-a: 6.3 µg/L. Trophic State Index: 57.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.9 ft | Not graded |
| Phosphorus | 72 µg/L | Poor |
| Chlorophyll-a (Algae) | 6.3 µg/L | Good |
| Trophic State Index (TSI) | 57 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Deep Lake
Compare lakeside cabins, hotels, and vacation rentals near Deep Lake in Ramsey 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.
Top-rated places to stay near Deep Lake
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Water Temperature
Deep Lake typically sits around 73°F at the surface in August. Summer average is about 75°F. Usually warmest in Jul (about 79°F) and coldest in May (about 61°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 35 field readings (2010–2022) via the EPA Water Quality Portal. See the full Deep Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 11 ft |
| Surface Area | 72 acres |
| Shoreline Length | 1.7 mi |
| Littoral Zone | 100% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Deep Lake
DNR Fisheries Survey Summary
3 surveys on file from MN DNR Fisheries. Most recent: 1995-07-12 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 23.19 | 0.23 lb |
| Black Crappie | 18.91 | 0.26 lb |
| Common Carp | 5.97 | 3.52 lb |
| Yellow Perch | 2.22 | 0.07 lb |
| White Crappie | 2.16 | 0.45 lb |
| Walleye | 1.86 | 2.55 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Black Crappie
Common Carp
Yellow Perch
From the 1995-07-12 survey
Sunfish and crappies dominated the catch, with black crappie and bluegill the most abundant. Moderate numbers of walleye, northern pike, channel catfish, muskellunge, and bowfin were present. Low numbers of largemouth bass, carp, white bass, yellow perch, bigmouth buffalo, black bullhead, golden shiner, and shorthead…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Deep Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — DeepFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.028 m/yr | 6 |
| Phosphorus | ↓ Declining | +2.34 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.86 µg/L/yr | 6 |
EPA Impairment Status
Deep Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN62-0043-00 · Official waterbody report · Matched by proximity (1.47 km)
County Ranking
Ranked #12 of 44 lakes in Ramsey County
Nearby Lakes With Higher Grades
Deep Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Ramsey County
Frequently asked questions about Deep Lake
What is the water quality grade for Deep Lake?
- Deep Lake in Ramsey County, Minnesota has a water quality grade of C (Fair). Water clarity: 3.9 ft visibility. Phosphorus: 72 µg/L. Chlorophyll-a (algae): 6.3 µg/L. Maximum depth: 11 ft. Surface area: 71.73 acres.
Is Deep Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Deep Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 6.3 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Deep Lake?
- Deep Lake typically sits around 73°F at the surface in August, from 35 EPA Water Quality Portal field readings (2010–2022). That is a typical value for the month, not a live reading.
How deep is Deep Lake?
- Deep Lake has a maximum depth of 11 feet. The lake covers 71.73 acres.
What fish are in Deep Lake?
- Fish species found in Deep Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, bowfin (dogfish), channel catfish, common carp, green sunfish, hybrid sunfish, largemouth bass, muskellunge, northern pike, shorthead redhorse, smallmouth bass, walleye, white bass, white crappie, white sucker, yellow perch. Deep Lake is located in Ramsey County, Minnesota.
Explore Deep Lake across LakeGrade
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High nutrients, frequent algae, reduced clarity
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Where this data comes from
133 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA133 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder