Lower Orono Lake
Sherburne County, Minnesota301 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Lower Orono Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Mercury
- 2 aquatic invasives
- 18 ft max depth
- Public access
- Limited data
Lower Orono Lake in Sherburne County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2.5 ft visibility. Phosphorus: 138 µg/L. Chlorophyll-a (algae): 76 µg/L. Maximum depth: 18 ft. Surface area: 300.5 acres.
Minnesota DNR's Targeted Survey on May 3, 2021 caught 5.83 northern pike per hour of electrofishing at Lower Orono Lake. DNR survey details →
Lower Orono Lake is a 301-acre highly nutrient-loaded hypereutrophic lake in Sherburne County, Minnesota with a maximum depth of 18 feet (3-foot average). Overall water quality is improving over recent sampling years. The lake supports 18 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 17 other monitored lakes in Sherburne County, Lower Orono Lake ranks #18 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-29. Methodology: how these readings are compared.
Lower Orono Lake covers about 300 acres in Sherburne County. It has one public boat landing. The median ice-out date is April 11, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Lower Orono Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Lower Orono Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing18 species recorded
- Ice seasonIce-out around Apr 11
Swimming conditions
Readings onlyRecreation use not supported
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. Lower Orono Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Lower Orono 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 Lower Orono Lake
These are the measurements Minnesota PCA publishes for Lower Orono 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 2.5 ft of visibility. Phosphorus 138 µg/L. Chlorophyll-a 76 µg/L. TSI 71.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 138µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 76µg/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. | 71 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Lower Orono Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lower Orono Lake typically sits around 63°F at the surface in September. Summer average is about 72°F. Usually warmest in Jul (about 77°F) and coldest in May (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (77°F).
Typical surface water temperature by month, from 10 field readings (2024–2025) via the EPA Water Quality Portal. See the full Lower Orono Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on May 3, 2021 caught 5.83 northern pike per hour of electrofishing at Lower Orono Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lower Orono Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
5 surveys on file from MN DNR Fisheries. Most recent: 2021-05-03 (Targeted Survey).
5 surveys on file · most recent 2021-05-03 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Smallmouth Bass | 12.89 | 8 in 2021-05-03 | 0.98 lb |
| Black Bullhead | 12.89 | 11 in 2019-08-09 | 0.41 lb |
| Yellow Perch | 9.17 | 5–10 in 2021-05-03 | 0.21 lb |
| White Sucker | 5.33 | 10–19 in 2019-08-09 | 1.28 lb |
| Black Crappie | 4.88 | 8–11 in 2021-05-03 | 0.28 lb |
| White Crappie | 4.84 | 6–7 in 2008-08-04 | 0.19 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
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.
Smallmouth Bass
Black Bullhead
Yellow Perch
White Sucker
From the 2021-05-03 survey
Orono Lake is a 281-acre reservoir formed by a dam on the Elk River in the City of Elk River in Sherburne County. Orono Lake has a maximum depth of 18 feet and there is a public access on the west side of the lake in a city park. The reservoir has had issues with sediment deposition from the Elk River over the years…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lower Orono Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — OronoFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — OronoFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — OronoPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
18 ft
Average depth
3.1 ft
Surface area
301 acres
Shoreline
12.2 mi
Littoral zone
94%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Recreation & Access
- Babcock Memorial ParkPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Lower Orono Lake
Compare lakeside cabins, hotels, and vacation rentals near Lower Orono Lake in Sherburne 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 Lower Orono Lake are listed below.
Top-rated places to stay near Lower Orono Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
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Fish Species
Click a species to see every lake where it is documented.
Fishing Lower Orono Lake
- → Lower Orono Lake fishing: DNR survey catch rates, species & stocking
- → Lower Orono Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → Lower Orono Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from Lower Orono Lake? (mercury & PFAS guide)
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 Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Ice season
Typical ice-out
Apr 11
Earliest Mar 30, 2007 · Latest Apr 17, 2008
Most recent ice-out
Apr 10
2022
6 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Lower Orono Lake is a man-made reservoir impounded by the Elk River (completed 1916), built primarily for recreation on the Elk River; gravity-type dam, 23 ft tall and 207 ft long.
- Surface area
- 300 ac
- Normal storage
- 1,600 ac-ft
- Max storage
- 2,800 ac-ft
- Drainage area
- 234 sq mi
- Hazard class
- High
- Owner
- City of Elk River
Source: USACE National Inventory of Dams, NID ID MN00516 · Operator website · Matched by proximity (0.12 km)
EPA Impairment Status
Lower Orono Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN71-0013-02 · Official waterbody report
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Lower Orono Lake under Clean Water Act (NPDES) discharge permits, including 1 classified by the EPA as major discharger. 1 facility has a reported Clean Water Act violation in the past three years.
- Elk River WwtpElk River · 1.4 mi away · NPDES MN0020788MajorRecent violation
- Great River EnergyHelen, Township Of · 1.4 mi away · NPDES MN0001988
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Sherburne County
Frequently asked questions about Lower Orono Lake
Where is Lower Orono Lake?
- Lower Orono Lake is a lake in Sherburne County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Lower Orono Lake?
- Lower Orono Lake in Sherburne County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2.5 ft visibility. Phosphorus: 138 µg/L. Chlorophyll-a (algae): 76 µg/L. Maximum depth: 18 ft. Surface area: 300.5 acres.
Is Lower Orono Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Lower Orono Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Lower Orono Lake?
- Lower Orono Lake typically sits around 63°F at the surface in September, from 10 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Lower Orono Lake?
- Lower Orono Lake has a maximum depth of 18 feet and an average depth of 3.1 feet. The lake covers 300.5 acres.
What fish are in Lower Orono Lake?
- Fish species found in Lower Orono Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), channel catfish, common carp, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, shorthead redhorse, silver redhorse, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Lower Orono Lake is located in Sherburne County, Minnesota.
What did the DNR fisheries survey find at Lower Orono Lake?
- Minnesota DNR's Targeted Survey on May 3, 2021 caught 5.83 northern pike per hour of electrofishing at Lower Orono Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lower Orono Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Lower Orono Lake thaw?
- Lower Orono Lake typically has ice-out around Apr 11.
Are there boat ramps on Lower Orono Lake?
- Lower Orono Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Babcock Memorial Park. Public access is listed as yes.
Can I fish at Lower Orono Lake?
- Lower Orono Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. 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 Lower Orono Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Sherburne County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Minnesota's cleanest lakes, ranked on agency measurements
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State Parks Near Lower Orono Lake
Other Lakes in Minnesota
Hypereutrophic Lakes in Minnesota
Where this data comes from
40 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
MNPCA40 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)
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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate