Swan Lake Max Depth is a 130-acre highly nutrient-loaded hypereutrophic lake in Carroll County, Iowa. Water quality is graded F based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available.
Source: EPA Water Quality Portal sampling records, Iowa DNR, last sampled 2024-09-04. Grade methodology: LakeGrade methodology.
Watch Swan Lake Max Depth water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1.4 ft of visibility. Chlorophyll-a: 74 µg/L. Trophic State Index: 73.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.4 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 74 µg/L | F |
| Trophic State Index (TSI) | 73 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 130 acres |
| Public Access | Yes |
Where to stay near Swan Lake Max Depth
Compare lakeside cabins, hotels, and vacation rentals near Swan Lake Max Depth in Carroll 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.
Top-rated places to stay near Swan Lake Max Depth
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 trip to Swan Lake Max Depth?
Get lake water-quality report cards plus the best cabin & lodging deals near Swan Lake Max Depth — straight to your inbox. No spam, unsubscribe anytime.
Planning a whole trip? See where to stay at Iowa’s top lakes →
Fishing Swan Lake Max Depth
Water Quality Trend: ↑ Improving
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.083 m/yr | 5 |
| Chlorophyll-a | ↑ Improving | -2.07 µg/L/yr | 5 |
Water Temperature
Swan Lake Max Depth averages about 76°F at the surface in summer, usually warmest in Jul (about 79°F) and coldest in May (about 64°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 29 field readings (2010–2023) via the EPA Water Quality Portal. See the full Swan Lake Max Depth water temperature breakdown →
Location & Depth Map
Free interactive depth-contour map of Swan Lake Max Depth, reaching a maximum surveyed depth of 10 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Iowa DNR.
County Ranking
Ranked #1 of 1 lakes in Carroll County
Cleaner Lakes Within 30 Miles
Swan Lake Max Depth holds Grade F. 3 nearby lakes hold higher grades.
- CArrowhead LakeSac County · 20.9 mi · Two grade letters higher (F → C)
- DYellow Smoke LakeCrawford County · 24.9 mi · Higher grade (F → D)
- DSpringbrook LakeGuthrie County · 26.4 mi · Higher grade (F → D)
Nearby Lakes in Carroll County
Explore Swan Lake Max Depth across LakeGrade
More Iowa Lake Rankings
Other Grade F Lakes in Iowa
Hypereutrophic Lakes in Iowa
More records, surveys & data sources
Reservoir Info (USACE NID)
Swan Lake Max Depth is a man-made reservoir impounded by the Swan Lake Dam (completed 1935), built primarily for fish and wildlife pond on the Trib to Middle Raccoon; earth-type dam, 10 ft tall and 900 ft long.
- Surface area
- 130 ac
- Normal storage
- 440 ac-ft
- Max storage
- 600 ac-ft
- Drainage area
- 1.4 sq mi
- Hazard class
- Low
- Owner
- Iowa Department of Natural Resources
Source: USACE National Inventory of Dams, NID ID IA04222 · Operator website · Matched by proximity (0.46 km)
EPA Impairment Status
Swan Lake Max Depth is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit IA 04-RAC-1199 · Official waterbody report · Matched by proximity (0.44 km)
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth is a modeled estimate.
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-09-04
Monitoring stations: 1