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LakeQuality

Round Lake

D
Grade D — Nutrient-rich
Nutrient-rich · #18 of 44 lakes in the county · 8 ft clear · Eutrophic · 72 acres · from C
Eutrophic

Round Lake in Ramsey County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 8 ft visibility. Phosphorus: 53 µg/L. Chlorophyll-a (algae): 10.1 µg/L. Surface area: 72 acres.

Clarity
8 ft
Typical in August
58°F
Mean depth
~14 ft est.
Area
72 acres
Type
Eutrophic
Trend
Declining
Public access
Yes
Ice-out
Apr 8

Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Round Lake

Next lake in Ramsey County

CPhalen Lake8.1 ft clear · Ramsey CountyView →
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Round Lake is a 72-acre productive, nutrient-rich eutrophic lake in Ramsey County, Minnesota with an estimated average depth of about 14 feet. Water quality is graded D based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 43 other monitored lakes in Ramsey County, Round Lake ranks #18 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-23. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Elevated nutrients

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.

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum

Compare the safest swimming lakes near St. Paul

Get alerts for Round Lake

Water Quality Grade: D (Nutrient-rich)

Moderate clarity, visible to about 8 ft. Phosphorus level: 53 µg/L. Chlorophyll-a: 10.1 µg/L. Trophic State Index: 54.

MetricValueGrade
Water Clarity (Secchi Depth)8 ftNot graded
Phosphorus53 µg/LPoor
Chlorophyll-a (Algae)10.1 µg/LFair
Trophic State Index (TSI)54Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Round Lake

Compare lakeside cabins, hotels, and vacation rentals near Round 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 Round Lake are listed below.

Top-rated places to stay near Round 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

Round Lake typically sits around 58°F at the surface in August. Summer average is about 57°F. Usually warmest in Aug (about 58°F) and coldest in Jan (about 37°F). These are typical values by month — not a live reading.

Jan
37°
Feb
37°
Mar
39°
Apr
42°
May
50°
Jun
55°
Jul
57°
Aug
58°
Sep
56°
Oct
47°
Nov
48°
Dec

Typical surface water temperature by month, from 2,314 field readings (20102025) via the EPA Water Quality Portal. See the full Round Lake water temperature breakdown →

Lake Details

CharacteristicValue
Average Depth~14 ft est.
Surface Area72 acres
Public AccessYes

Depth marked “est.” is a modeled estimate from HydroLAKES, not a measured survey. Minnesota has not published bathymetry for Round Lake.

Lake Size & Watershed

Watershed (drainage) area
20 sq mi
Mean depth (modeled estimate)
~14 ft est.
Shoreline
2.8 mi
Elevation
846 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Lake PhalenPublic

Fishing Round 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.

Eurasian watermilfoil

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Round Lake. 1 report on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.117 m/yr6
Phosphorus Stable-0.03 µg/L/yr6
Chlorophyll-a Declining+1.1 µg/L/yr6
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (8 observations).

Typical Ice-Out
Apr 8
EarliestLatest
Ice-Out2024-03-03 (2024)2018-04-28 (2018)
Ice-In2024-11-30 (2024)2024-11-30 (2024)

Most recent ice-out: 2026-03-29

Reservoir Info (USACE NID)

Round Lake is a man-made reservoir impounded by the Keller Lake (completed 1938), built primarily for recreation on the Keller Creek; gravity-type dam, 12 ft tall and 50 ft long.

Surface area
72 ac
Normal storage
246 ac-ft
Max storage
450 ac-ft
Drainage area
52 sq mi
Hazard class
Low
Owner
RWMWD

Source: USACE National Inventory of Dams, NID ID MN00398 · Operator website · Matched by proximity (0.45 km)

EPA Impairment Status

Round Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

MercuryPFAS

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit MN62-0013-00 · Official waterbody report · Matched by proximity (1.02 km)

County Ranking

Ranked #18 of 44 lakes in Ramsey County

Nearby Lakes With Higher Grades

Round Lake holds Grade D. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Ramsey County

Frequently asked questions about Round Lake

What is the water quality grade for Round Lake?

Round Lake in Ramsey County, Minnesota has a water quality grade of D (Nutrient-rich). Water clarity: 8 ft visibility. Phosphorus: 53 µg/L. Chlorophyll-a (algae): 10.1 µg/L. Surface area: 72 acres.

Is Round Lake safe to swim in?

Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Round Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 10.1 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Round Lake?

Round Lake typically sits around 58°F at the surface in August, from 2,314 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.

How deep is Round Lake?

No published bathymetric survey covers Round Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 14 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 72 acres.

When does Round Lake thaw?

Round Lake typically has ice-out around Apr 8.

Are there boat ramps on Round Lake?

Round Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Phalen. Public access is listed as yes.

Where this data comes from

511 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 WaterMNPCA511 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, Nephelometric Method
  • Turbidity by Nephelometry
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

Named boat-access points from the USGS National Boat Ramps inventory

Ice data from Minnesota DNR Climate