Gustafson Lake
Buena Vista County, Iowa10 acresView mapDirections
Iowa DNR publishes the water-quality measurements for Gustafson Lake. Here is what has been measured.
- Eutrophic
- Impaired · Pathogens (E. coli, fecal)
- Public access
Gustafson Lake in Buena Vista County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 2.3 ft visibility. Phosphorus: 48.2 µg/L. Chlorophyll-a (algae): 27 µg/L. Surface area: 9.7 acres.
Gustafson Lake is a 10-acre productive, nutrient-rich eutrophic lake in Buena Vista County, Iowa. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 2 other monitored lakes in Buena Vista County, Gustafson Lake ranks #3 for water quality.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2022-09-12. Methodology: how these readings are compared.
Swimming conditions
Readings onlyBacteria advisory
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. Gustafson Lake is listed impaired under Clean Water Act §303(d) (IR 5) for pathogens (E. coli, fecal), turbidity. Check local advisories before you swim.
Whether Gustafson 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 Gustafson Lake
These are the measurements Iowa DNR publishes for Gustafson Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.3 ft of visibility. Phosphorus 48.2 µg/L. Chlorophyll-a 27 µg/L. TSI 63.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 48.2µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 27µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 63 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Gustafson Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Gustafson Lake typically sits around 77°F at the surface in August. Summer average is about 76°F. Usually warmest in Jul (about 79°F) and coldest in Jun (about 71°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (71°F) to its warmest (79°F).
Typical surface water temperature by month, from 9 field readings (2018–2022) via the EPA Water Quality Portal. See the full Gustafson Lake water temperature breakdown →
Lake Details
Surface area
10 acres
Public access
Yes
Listed by Iowa DNR
No bathymetric survey has been published for Gustafson Lake, so its depth is not documented here.
Stays via Stay22
Stays near Gustafson Lake
Compare lakeside cabins, hotels, and vacation rentals near Gustafson Lake in Buena Vista 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 readings cover nutrients and algae, not lodging. Cabins and rentals around Gustafson Lake are listed below.
Top-rated places to stay near Gustafson Lake
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Fishing Gustafson Lake
Water quality readings over time
3 seasons of samples on record (2020–2022). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving3 years
Phosphorus
Worsening+1.4 µg/L/yr3 years
Chlorophyll-a
Improving-3.45 µg/L/yr3 years
Reservoir Info (USACE NID)
Gustafson Lake is a man-made reservoir impounded by the Gustafson Lake Dam (completed 1974), built primarily for recreation on the TR-LITTLE SIOUX RIVER; earth-type dam, 49 ft tall and 1,150 ft long.
- Surface area
- 9.7 ac
- Normal storage
- 90 ac-ft
- Max storage
- 176 ac-ft
- Drainage area
- 0.36 sq mi
- Hazard class
- Significant
- Owner
- Iowa Department of Transportation
All listed purposes: Recreation;Other.
Source: USACE National Inventory of Dams, NID ID IA02159 · Operator website
EPA Impairment Status
Gustafson Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Recreation.
Source: EPA ATTAINS assessment unit IA 06-LSR-1625 · Official waterbody report
Regulated Pollution Sources Nearby
3 EPA-permitted facilities operate within about 5 miles of Gustafson Lake under Clean Water Act (NPDES) discharge permits. 3 facilities have a reported Clean Water Act violation in the past three years.
- Sioux Rapids City Of StpSioux Rapids · 1.3 mi away · NPDES IA0042951Recent violation
- Rembrandt Enterprises, Inc.Rembrandt · 3.9 mi away · NPDES IA0076554Recent violation
- Rembrandt City Of StpRembrandt · 4.2 mi away · NPDES IA0033219Recent violation
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 Buena Vista County
Frequently asked questions about Gustafson Lake
Where is Gustafson Lake?
- Gustafson Lake is a lake in Buena Vista County, Iowa. Its water-quality measurements are published by Iowa DNR and shown on this page as reported.
What is the water quality of Gustafson Lake?
- Gustafson Lake in Buena Vista County, Iowa has water-quality measurements published by Iowa DNR, shown here as reported. Water clarity: 2.3 ft visibility. Phosphorus: 48.2 µg/L. Chlorophyll-a (algae): 27 µg/L. Surface area: 9.7 acres.
Is Gustafson Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Gustafson Lake is listed impaired under Clean Water Act §303(d) (IR 5) for pathogens (E. coli, fecal), turbidity. Check local advisories before you swim.
What is the water temperature of Gustafson Lake?
- Gustafson Lake typically sits around 77°F at the surface in August, from 9 EPA Water Quality Portal field readings (2018–2022). That is a typical value for the month, not a live reading.
Can I fish at Gustafson Lake?
- Public access to Gustafson Lake is listed as yes on the lake record. 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.
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Where this data comes from
36 measurements from 1 monitoring station, 2020–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Iowa DNR Surface Water Monitoring Data
21IOWA_WQX36 samples · 2020–2022
Analytical methods
- Unknown
- Phosphorus by Colorimetry
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
- 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
Impairment status from EPA ATTAINS 303(d) database
Regulated discharger data from EPA ECHO (ICIS-NPDES)