Johanna Lake
Johanna Lake in Ramsey County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 6.6 ft visibility. Phosphorus: 41 µg/L. Chlorophyll-a (algae): 8 µg/L. Maximum depth: 43 ft. Surface area: 211.91 acres.
- Clarity
- 6.6 ft
- Typical in August
- 64°F
- Max depth
- 43 ft
- Area
- 212 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 5
- Open water
- 242 days
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Johanna Lake →
Next lake in Ramsey County
Johanna Lake is a 212-acre productive, nutrient-rich eutrophic lake in Ramsey County, Minnesota with a maximum depth of 43 feet (17-foot average). Water quality is graded D based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 13 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available with 1 public boat landing. Compared to the 43 other monitored lakes in Ramsey County, Johanna Lake ranks #19 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.
Watch Johanna Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Grade onlyBacteria B
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.
Based on E. coli testing, Johanna Lake rarely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 4.3% of 92 samples across 3 seasons.
This is a historical summary of past testing, not a current condition — bacteria levels change quickly, especially after rain. Always check Minnesota’s current beach and health-department advisories before swimming.
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 6.6 ft. Phosphorus level: 41 µg/L. Chlorophyll-a: 8 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.6 ft | Not graded |
| Phosphorus | 41 µg/L | Poor |
| Chlorophyll-a (Algae) | 8 µg/L | Fair |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Johanna Lake
Compare lakeside cabins, hotels, and vacation rentals near Johanna 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Johanna Lake are listed below.
Top-rated places to stay near Johanna Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Johanna Lake typically sits around 64°F at the surface in August. Summer average is about 62°F. Usually warmest in Jul (about 64°F) and coldest in Feb (about 35°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 1,092 field readings (2010–2025) via the EPA Water Quality Portal. See the full Johanna Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 43 ft |
| Average Depth | 17 ft |
| Surface Area | 212 acres |
| Shoreline Length | 3 mi |
| Littoral Zone | 45% |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Johanna LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Johanna 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.
DNR Fisheries Survey Summary
11 surveys on file from MN DNR Fisheries. Most recent: 2021-08-09 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 59.04 | 0.13 lb |
| Yellow Perch | 19.05 | 0.1 lb |
| Black Crappie | 11.74 | 0.14 lb |
| Northern Pike | 4.32 | 3.77 lb |
| Pumpkinseed | 2.98 | 0.12 lb |
| Largemouth Bass | 2.87 | 0.71 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
Yellow Perch
Black Crappie
Northern Pike
From the 2021-08-09 survey
Lake Johanna is a 213-acre, eutrophic lake located in Arden Hills, 7.5 miles northwest of St. Paul. The contributing watershed is characterized by residential, commercial, industrial and major roadways. Overall, water quality in Lake Johanna is very good. The most recent data indicates that it is one of the best lakes…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Johanna Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — JohannaFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — JohannaFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — JohannaPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.111 m/yr | 6 |
| Phosphorus | ↓ Declining | +1.5 µg/L/yr | 6 |
| Chlorophyll-a | ↓ Declining | +2.43 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (15 observations).
Estimated open water season: 242 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2000-03-08 (2000) | 2013-04-29 (2013) |
| Ice-In | 1994-11-30 (1994) | 2004-12-14 (2004) |
Most recent ice-out: 2013-04-29
EPA Impairment Status
Johanna Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN62-0078-00 · Official waterbody report
County Ranking
Ranked #19 of 44 lakes in Ramsey County
Nearby Lakes With Higher Grades
Johanna Lake holds Grade D. 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 Johanna Lake
What is the water quality grade for Johanna Lake?
- Johanna Lake in Ramsey County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 6.6 ft visibility. Phosphorus: 41 µg/L. Chlorophyll-a (algae): 8 µg/L. Maximum depth: 43 ft. Surface area: 211.91 acres.
Is Johanna Lake safe to swim in?
- Based on E. coli testing, Johanna Lake rarely exceeded the EPA safe-swimming threshold (235 MPN/100mL) — on 4.3% of 92 samples across 3 seasons. That works out to a bacteria swim-safety grade of B — a historical summary of past testing, not a current reading. Johanna Lake has a water quality grade of D (Nutrient-rich). Bacteria levels can spike quickly after heavy rain, so always check Minnesota's current beach and health-department advisories before you swim.
What is the water temperature of Johanna Lake?
- Johanna Lake typically sits around 64°F at the surface in August, from 1,092 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Johanna Lake?
- Johanna Lake has a maximum depth of 43 feet and an average depth of 17 feet. The lake covers 211.91 acres.
What fish are in Johanna Lake?
- Fish species found in Johanna Lake include black crappie, bluegill, bowfin (dogfish), green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, tiger muskellunge, walleye, white sucker, yellow bullhead, yellow perch. Johanna Lake is located in Ramsey County, Minnesota.
When does Johanna Lake thaw?
- Johanna Lake typically has ice-out around Apr 5. Ice typically forms around Dec 3. The open water season is approximately 242 days.
Are there boat ramps on Johanna Lake?
- Johanna Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Johanna Lake. Public access is listed as yes.
Explore Johanna Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
Fish species and top-graded lakes across Minnesota
Fish species and best lakes in Ramsey County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
Minnesota's cleanest and most-polluted lakes, ranked
More Minnesota Lake Rankings
State Parks Near Johanna Lake
Other Grade D Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
431 measurements from 4 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA431 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 2130 B ~ Nephelometric Method
- Turbidity by Nephelometry
Monitoring station identifiers (4)
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate