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LakeQuality

Sarah Lake

F
Grade F — Algae-prone
Algae-prone · #73 of 81 lakes in the county · 3.1 ft clear · Eutrophic · 557 acres
Eutrophic

Sarah Lake in Hennepin County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3.1 ft visibility. Phosphorus: 106.1 µg/L. Chlorophyll-a (algae): 34.3 µg/L. Maximum depth: 59 ft. Surface area: 557.23 acres.

Clarity
3.1 ft
Typical in August
60°F
Max depth
59 ft
Area
557 acres
Type
Eutrophic
Trend
Declining
Public access
Yes
Ice-out
Apr 3
Open water
248 days

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

Next lake in Hennepin County

DEast Sarah Lake3.5 ft clear · Hennepin CountyView →
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Sarah Lake is a 557-acre productive, nutrient-rich eutrophic lake in Hennepin County, Minnesota with a maximum depth of 59 feet. Water quality is graded F based on 3 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available with 1 public boat landing. Compared to the 80 other monitored lakes in Hennepin County, Sarah Lake ranks #73 for water quality.

Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-13. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Algae risk

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.

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom

Compare the safest swimming lakes near Minneapolis

Get alerts for Sarah Lake

Water Quality Grade: F (Algae-prone)

Very murky, less than 3.1 ft of visibility. Phosphorus level: 106.1 µg/L. Chlorophyll-a: 34.3 µg/L. Trophic State Index: 66.

MetricValueGrade
Water Clarity (Secchi Depth)3.1 ftNot graded
Phosphorus106.1 µg/LPoor
Chlorophyll-a (Algae)34.3 µg/LPoor
Trophic State Index (TSI)66Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Sarah Lake

Compare lakeside cabins, hotels, and vacation rentals near Sarah Lake in Hennepin 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 Sarah Lake are listed below.

Top-rated places to stay near Sarah 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

Sarah Lake typically sits around 60°F at the surface in August. Summer average is about 58°F. Usually warmest in Aug (about 60°F) and coldest in Apr (about 45°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
45°
May
51°
Jun
56°
Jul
59°
Aug
60°
Sep
59°
Oct
55°
Nov
Dec

Typical surface water temperature by month, from 2,085 field readings (20102025) via the EPA Water Quality Portal. See the full Sarah Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth59 ft
Surface Area557 acres
Shoreline Length7.5 mi
Littoral Zone67%
Public AccessYes

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Lake Sarah, Kohen Memorial LandingPublic

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Sarah 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 Fisheries Survey Summary

10 surveys on file from MN DNR Fisheries. Most recent: 2022-07-18 (Standard Survey).

Top Species by Catch Rate

SpeciesAvg CPUEAvg Weight
Bluegill43.880.17 lb
Black Crappie19.430.17 lb
Bluntnose Minnow16.09
Largemouth Bass14.211.45 lb
IOD9.37
Yellow Bass8.531.04 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

475 fish · 28 in · 2022-07-18
1226102345678

Black Crappie

502 fish · 410 in · 2022-07-18
151760trophy 1045678910

Largemouth Bass

4 fish · 1315 in · 2022-07-18
210131415

Yellow Bass

348 fish · 515 in · 2022-07-18
8643056789101112131415

From the 2022-07-18 survey

Lake Sarah is a 561-acre lake with a maximum depth of 59 feet, located southeast of Rockford, in western Hennepin County. Sarah is primarily managed for Largemouth Bass and Northern Pike, and also holds healthy populations of Black Crappie, Bluegill, Yellow Bullhead, and Walleye. Walleye have been stocked privately…

Source: MN DNR LakeFinder Fisheries Lake Survey

DNR Reports & Resources

Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Sarah Lake. 3 reports 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-0.047 m/yr6
Phosphorus Declining+22.77 µg/L/yr4
Chlorophyll-a Declining+2.46 µg/L/yr4
See year-by-year chart →

Ice Season

Historical ice data from Minnesota DNR (18 observations).

Typical Ice-Out
Apr 3
Typical Ice-In
Dec 7

Estimated open water season: 248 days

EarliestLatest
Ice-Out2012-03-18 (2012)2018-05-02 (2018)
Ice-In2012-11-20 (2012)2015-12-19 (2015)

Most recent ice-out: 2022-04-14

EPA Impairment Status

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

Causes of impairment

Impaired biota (cause unknown)MercuryNutrients (phosphorus, nitrogen)

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

Source: EPA ATTAINS assessment unit MN27-0191-01 · Official waterbody report · Matched by proximity (0.73 km)

County Ranking

Ranked #73 of 81 lakes in Hennepin County

Nearby Lakes With Higher Grades

Sarah Lake holds Grade F. 3 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 Hennepin County

Frequently asked questions about Sarah Lake

What is the water quality grade for Sarah Lake?

Sarah Lake in Hennepin County, Minnesota has a water quality grade of F (Algae-prone). Water clarity: 3.1 ft visibility. Phosphorus: 106.1 µg/L. Chlorophyll-a (algae): 34.3 µg/L. Maximum depth: 59 ft. Surface area: 557.23 acres.

Is Sarah Lake safe to swim in?

Algae and nutrients are often high — check current advisories before swimming. Skip the water if you see scum or a paint-like bloom. Sarah Lake has a water quality grade of F (Algae-prone). Algae concentration (chlorophyll-a) is 34.3 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Sarah Lake?

Sarah Lake typically sits around 60°F at the surface in August, from 2,085 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.

How deep is Sarah Lake?

Sarah Lake has a maximum depth of 59 feet. The lake covers 557.23 acres.

What fish are in Sarah Lake?

Fish species found in Sarah Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead, yellow perch. Sarah Lake is located in Hennepin County, Minnesota.

When does Sarah Lake thaw?

Sarah Lake typically has ice-out around Apr 3. Ice typically forms around Dec 7. The open water season is approximately 248 days.

Are there boat ramps on Sarah Lake?

Sarah Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lake Sarah, Kohen Memorial Landing. Public access is listed as yes.

Eutrophic Lakes in Minnesota

Where this data comes from

342 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 WaterMNPCA342 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
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