Upper Gar Lake
Dickinson County, IowaView mapDirections
Nutrients and algae sit mid-range for this region.
- Eutrophic
- #3 of 8 in the county
- Public access
Upper Gar Lake in Dickinson County, Iowa has a water quality grade of C (Fair). Water clarity: 3.9 ft visibility. Phosphorus: 52.5 µg/L. Chlorophyll-a (algae): 13.1 µg/L.
- Clarity
- 3.9 ft
- Typical in September
- 72°F
- Type
- Eutrophic
- Phosphorus
- 52.5 µg/L
- Chlorophyll-a
- 13.1 µg/L
- Trend
- → Stable
- Public access
- Yes
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Stays near Upper Gar Lake
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Watch Upper Gar Lake’s letter
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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 quality is graded C based on 2 sampling years through 2024. 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. Grade methodology: LakeQuality methodology.
What Upper Gar Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
Swimming Safety
Grade onlyModerate
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 C is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: C (Fair)
Murky, only visible to about 3.9 ft. Phosphorus 52.5 µg/L. Chlorophyll-a 13.1 µg/L. TSI 58. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.9 ft | Not graded |
| Phosphorus | 52.5 µg/L | Fair |
| Chlorophyll-a (Algae) | 13.1 µg/L | Good |
| Trophic State Index (TSI) | 58 | Eutrophic |
High nutrients, frequent algae, reduced clarity
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.
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
Fishing Upper Gar Lake
Water Quality Trend: → Stable
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.1 m/yr | 5 |
| Phosphorus | → Stable | +0.55 µg/L/yr | 4 |
| Chlorophyll-a | ↑ Improving | -2.63 µg/L/yr | 5 |
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.
County Ranking
Ranked #3 of 8 lakes in Dickinson County
Nearby Lakes With Higher Grades
Upper Gar Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
See full comparison →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. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Upper Gar Lake?
- Upper Gar Lake in Dickinson County, Iowa has a water quality grade of C (Fair). 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?
- The C is nutrients and algae, 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.
Explore Upper Gar Lake across LakeQuality
Species activity outlook by water temperature and season
Top lakes and where to stay in the Iowa Great Lakes area
Where to stay at Iowa's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
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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)
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)
Named boat-access points from the USGS National Boat Ramps inventory