Upper Gar Lake
Dickinson County, IowaView mapDirections
Iowa DNR publishes the water-quality measurements for Upper Gar Lake. Here is what has been measured.
- Eutrophic
- Public access
Upper Gar Lake in Dickinson County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 52.5 µg/L. Chlorophyll-a (algae): 13.1 µg/L.
Free interactive depth-contour map of Upper Gar Lake, reaching a maximum surveyed depth of 7 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
Upper Gar Lake is a productive, nutrient-rich eutrophic lake in Dickinson County, Iowa. Water clarity is declining over recent sampling years. Limited fish-species data available. Public access is available with 2 public boat landings. Compared to the 7 other monitored lakes in Dickinson County, Upper Gar Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-10. Methodology: how these readings are compared.
What Upper Gar Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
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 Upper Gar Lake is safe to swim in today is a call for the Iowa Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Upper Gar Lake
These are the measurements Iowa DNR publishes for Upper Gar Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 3.9 ft. Phosphorus 52.5 µg/L. Chlorophyll-a 13.1 µg/L. TSI 58.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 52.5µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 13.1µg/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. | 58 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Upper Gar Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Upper Gar Lake typically sits around 72°F at the surface in September. Summer average is about 75°F. Usually warmest in Jul (about 80°F) and coldest in Jun (about 69°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (69°F) to its warmest (80°F).
Typical surface water temperature by month, from 27 field readings (2010–2023) via the EPA Water Quality Portal. See the full Upper Gar Lake water temperature breakdown →
Recreation & Access
- Upper GarPublic
- Unknown NameSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Upper Gar Lake
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Top-rated places to stay near Upper Gar Lake
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Fishing Upper Gar Lake
Water Quality Trend: Stable
Based on 5 years of monitoring (2020–2024).
Water clarity
Worsening5 years
Phosphorus
Stable+0.55 µg/L/yr4 years
Chlorophyll-a
Improving-2.63 µg/L/yr5 years
Regulated Pollution Sources Nearby
2 EPA-permitted facilities operate within about 5 miles of Upper Gar Lake under Clean Water Act (NPDES) discharge permits.
- Dry Dock DevelopmentArnolds Park · 0.4 mi away · NPDES IA0053439
- Former Okoboji Boats PropertyOkoboji · 0.7 mi away · NPDES IA0053666
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 Dickinson County
Frequently asked questions about Upper Gar Lake
Where is Upper Gar Lake?
- Upper Gar Lake is a lake in Dickinson County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Upper Gar Lake?
- Upper Gar Lake in Dickinson County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 3.9 ft visibility. Phosphorus: 52.5 µg/L. Chlorophyll-a (algae): 13.1 µg/L.
Is Upper Gar 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 Upper Gar Lake?
- Upper Gar Lake typically sits around 72°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.
Are there boat ramps on Upper Gar Lake?
- Upper Gar Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Upper Gar, Unknown Name. Public access is listed as yes.
Can I fish at Upper Gar Lake?
- Upper Gar Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Iowa's fish and wildlife agency, so check its current regulations before you go.
Explore Upper Gar Lake across LakeQuality
More lakes in Iowa
Other Lakes in Iowa
Eutrophic Lakes in Iowa
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 Data
21IOWA_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)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Named boat-access points from the USGS National Boat Ramps inventory