Lower Prior Lake
Scott County, Minnesota956 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Lower Prior Lake. Here is what has been measured.
- Mesotrophic
- 2 aquatic invasives
- 60 ft max depth
- Public access
Lower Prior Lake in Scott County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 27 µg/L. Chlorophyll-a (algae): 4.8 µg/L. Maximum depth: 60 ft. Surface area: 956.16 acres.
Minnesota DNR's Standard Survey on July 17, 2024 caught 1.12 walleye per gill net at Lower Prior Lake. DNR survey details →
Free interactive depth-contour map of Lower Prior Lake, reaching a maximum surveyed depth of 50 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Lower Prior Lake is a 956-acre mesotrophic lake in Scott County, Minnesota with a maximum depth of 60 feet. Overall water quality is declining over recent sampling years. The lake supports 15 documented fish species including black crappie, bluegill, and brown bullhead. Public access is available with 1 public boat landing. Compared to the 20 other monitored lakes in Scott County, Lower Prior Lake ranks #4 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-13. Methodology: how these readings are compared.
Lower Prior Lake covers about 960 acres in Scott County. It has one public boat landing. The median ice-out date is April 4, which is when the open-water season begins. If you are planning to stay, you can search lake houses and cabins around Lower Prior Lake on Vrbo, or look for a hotel room near the lake on Booking.com or Expedia.
What Lower Prior Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10 ft of visibility
- Boat launch1 documented ramp
- Fishing15 species recorded
- Ice seasonIce-out around Apr 4
- Deep water60 ft surveyed max depth
Swimming conditions
Readings onlyModerate algae
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 Lower Prior 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 Prior Lake
These are the measurements Minnesota PCA publishes for Lower Prior Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10 ft. Phosphorus 27 µg/L. Chlorophyll-a 4.8 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 27µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 4.8µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Lower Prior Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Lower Prior Lake typically sits around 60°F at the surface in October. Summer average is about 69°F. Usually warmest in Aug (about 71°F) and coldest in Apr (about 46°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (46°F) to its warmest (71°F).
Typical surface water temperature by month, from 1,637 field readings (2010–2025) via the EPA Water Quality Portal. See the full Lower Prior Lake water temperature breakdown →
Minnesota DNR's Standard Survey on July 17, 2024 caught 1.12 walleye per gill net at Lower Prior Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lower Prior Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
17 surveys on file from MN DNR Fisheries. Most recent: 2025-09-09 (Targeted Survey).
17 surveys on file · most recent 2025-09-09 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 24.77 | 2–8 in 2024-07-17 | 0.17 lb |
| Bluntnose Minnow | 12.85 | ||
| Largemouth Bass | 7.39 | 5–17 in 2024-07-17 | 0.54 lb |
| Golden Shiner | 6.29 | 7 in 2021-07-20 | 0.17 lb |
| Yellow Bullhead | 3.40 | 7–14 in 2024-07-17 | 0.82 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.
Bluegill
Largemouth Bass
Golden Shiner
Yellow Bullhead
From the 2025-09-09 survey
Minnesota DNR Fisheries IBI program staff conducted an assessment of lakeshore habitat on Lower Prior Lake on September 9th 2025, following the Score the Shore survey protocols. The assessment consisted of 119 survey sites evenly spaced 200 meters around the lake. Assessments were made in three habitat zones:…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lower Prior Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Lower PriorFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — Lower PriorFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Lower PriorPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
60 ft
Surface area
956 acres
Shoreline
14.7 mi
Littoral zone
39%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Recreation & Access
- Sand PointPublic
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 Prior Lake
Compare lakeside cabins, hotels, and vacation rentals near Lower Prior Lake in Scott 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 Lower Prior 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 →
Follow Lower Prior Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Lower Prior Lake
- → Lower Prior Lake fishing: DNR survey catch rates, species & stocking
- → Lower Prior Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → Lower Prior Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from Lower Prior 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: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.89 µg/L/yr5 years
Chlorophyll-a
Worsening+0.4 µg/L/yr5 years
Ice season
Typical ice-out
Apr 4
Earliest Mar 3, 2024 · Latest May 2, 2018
Typical ice-in
Dec 1
Earliest Nov 15, 1986 · Latest Dec 26, 2001
Most recent ice-out
Mar 25
2025
62 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
Lower Prior Lake is a man-made reservoir impounded by the Prior Lake on the Minnesota River-TR; gravity-type dam, 12 ft tall and 8 ft long.
- Surface area
- 1,056 ac
- Normal storage
- 1,760 ac-ft
- Drainage area
- 35 sq mi
- Hazard class
- Low
- Owner
- MNDNR
Source: USACE National Inventory of Dams, NID ID MN01328 · Operator website
Nearby Lakes in Scott County
Frequently asked questions about Lower Prior Lake
Where is Lower Prior Lake?
- Lower Prior Lake is a lake in Scott 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 Prior Lake?
- Lower Prior Lake in Scott County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 27 µg/L. Chlorophyll-a (algae): 4.8 µg/L. Maximum depth: 60 ft. Surface area: 956.16 acres.
Is Lower Prior 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 Lower Prior Lake?
- Lower Prior Lake typically sits around 60°F at the surface in October, from 1,637 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Lower Prior Lake?
- Lower Prior Lake has a maximum depth of 60 feet. The lake covers 956.16 acres.
What fish are in Lower Prior Lake?
- Fish species found in Lower Prior Lake include black crappie, bluegill, brown bullhead, common carp, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white bass, white crappie, white sucker, yellow bullhead, yellow perch. Lower Prior Lake is located in Scott County, Minnesota.
What did the DNR fisheries survey find at Lower Prior Lake?
- Minnesota DNR's Standard Survey on July 17, 2024 caught 1.12 walleye per gill net at Lower Prior Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Lower Prior Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Lower Prior Lake thaw?
- Lower Prior Lake typically has ice-out around Apr 4. Ice typically forms around Dec 1. The open water season is approximately 241 days.
Are there boat ramps on Lower Prior Lake?
- Lower Prior Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Sand Point. Public access is listed as yes.
Can I fish at Lower Prior Lake?
- Lower Prior 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 Prior 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 Scott County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Minnesota River Watershed, ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Lower Prior Lake
Other Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Compare Lower Prior Lake With Nearby Lakes
Where this data comes from
471 measurements from 3 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
MNPCA471 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 4500 N C ~ Persufate Method for Total Nitrogen
- Turbidity, Nephelometric Method
Monitoring station identifiers (3)
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate