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LakeQuality

Lower Gar Lake

Dickinson County, IowaView mapDirections

D
Nutrient-rich

Nutrients and algae run above the regional average.

Water temp
~71°F
Typical for Sep · EPA WQP
Clarity
2.6 ft
Secchi · sampled 2024
Level
No reading
No gauge
Trend
Improving
5 years of samples
  • Eutrophic
  • #5 of 8 in the county

Lower Gar Lake in Dickinson County, Iowa has a water quality grade of D (Nutrient-rich). Water clarity: 2.6 ft visibility. Phosphorus: 71.5 µg/L. Chlorophyll-a (algae): 20.7 µg/L.

Clarity
2.6 ft
Typical in September
71°F
Type
Eutrophic
Phosphorus
71.5 µg/L
Chlorophyll-a
20.7 µg/L
Trend
Improving
Loading map…

Stays via Stay22

Stays near Lower Gar Lake

Compare lakeside cabins, hotels, and vacation rentals near Lower Gar Lake in Dickinson County, Iowa — 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 Lower Gar Lake are listed below.

Top-rated places to stay near Lower Gar Lake

Prices for Sep 11–13, 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 Iowa’s top lakes →

Watch Lower Gar Lake’s letter

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Free interactive depth-contour map of Lower Gar Lake, reaching a maximum surveyed depth of 6 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.

Lower Gar Lake is a productive, nutrient-rich eutrophic lake in Dickinson County, Iowa. Water quality is graded D based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Compared to the 7 other monitored lakes in Dickinson County, Lower Gar Lake ranks #5 for water quality.

Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-10. Grade methodology: LakeQuality methodology.

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.

The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

Compare the safest swimming lakes near Mankato

Get alerts for Lower Gar Lake

Water Quality Grade: D (Nutrient-rich)

Very murky, less than 2.6 ft of visibility. Phosphorus 71.5 µg/L. Chlorophyll-a 20.7 µg/L. TSI 63. The letter is not a swimming clearance.

MetricValueGrade
Water Clarity (Secchi Depth)2.6 ftNot graded
Phosphorus71.5 µg/LPoor
Chlorophyll-a (Algae)20.7 µg/LPoor
Trophic State Index (TSI)63Eutrophic

High nutrients, frequent algae, reduced clarity

Water Temperature

Lower Gar Lake typically sits around 71°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 81°F) and coldest in May (about 70°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
70°
Jun
71°
Jul
81°
Aug
74°
Sep
71°
Oct
Nov
Dec

Typical surface water temperature by month, from 27 field readings (20102023) via the EPA Water Quality Portal. See the full Lower Gar Lake water temperature breakdown →

Fishing Lower Gar Lake

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.15 m/yr5
Phosphorus Improving-1.55 µg/L/yr4
Chlorophyll-a Improving-0.4 µg/L/yr5
See year-by-year chart →

Regulated Pollution Sources Nearby

5 EPA-permitted facilities operate within about 5 miles of Lower Gar 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.

  • Iowa Great Lakes Sanitary District Stp
    Milford · 1.2 mi away · NPDES IA0059765
    MajorRecent violation
  • Iowa Dot Ia 86 Hma Paved Shoulders
    Milford · 2 mi away · NPDES IA0052357
  • Dctb Hwy 86 Trail - Wetland Project
    Wahpeton · 2 mi away · NPDES IA0077445
  • Derner'S Of Milford, Inc.
    Milford · 3.7 mi away · NPDES IA0077593
  • Magellan Pipeline Company, L.P. - Milford Terminal
    Milford · 4.6 mi away · NPDES IA0071358

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.

County Ranking

Ranked #5 of 8 lakes in Dickinson County

Nearby Lakes With Higher Grades

Lower Gar Lake holds Grade D. 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 Dickinson County

Frequently asked questions about Lower Gar Lake

Where is Lower Gar Lake?

Lower Gar Lake is a lake in Dickinson County, Iowa. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Lower Gar Lake?

Lower Gar Lake in Dickinson County, Iowa has a water quality grade of D (Nutrient-rich). Water clarity: 2.6 ft visibility. Phosphorus: 71.5 µg/L. Chlorophyll-a (algae): 20.7 µg/L.

Is Lower Gar Lake safe to swim in?

The D is nutrients and algae, not a swimming clearance. Check local advisories before you swim.

What is the water temperature of Lower Gar Lake?

Lower Gar Lake typically sits around 71°F at the surface in September, from 27 EPA Water Quality Portal field readings (2010–2023). That is a typical value for the month, not a live reading.

Where this data comes from

54 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Iowa DNR Surface Water Monitoring Data21IOWA_WQX54 samples · 2020–2024

Analytical methods

  • Unknown
  • Phosphorus by Colorimetry
  • 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
  • In-Vitro Determination of Chlorophyll
  • ISU modification of APHA 2130-B
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

Regulated discharger data from EPA ECHO (ICIS-NPDES)