Is Twelve Mile Lake Safe for Swimming?
Twelve Mile Lake in Union County, Iowa has nutrient and algae measurements on record from state and federal monitoring. Chlorophyll-a in the monitoring record runs high enough that algae is a factor. A water-quality reading is not a swimming clearance. The state water agency and county health departments post current advisories; check them before you swim.. Water clarity: 2.4 ft visibility. Phosphorus: 79 µg/L. Chlorophyll-a (algae): 45 µg/L. Always check local health department advisories before swimming.
Key Metrics
| Metric | Value |
|---|---|
| Water Clarity (Secchi Depth) | 2.4 ft |
| Phosphorus | 79 μg/L |
| Chlorophyll-a (Algae) | 45 μg/L |
| Location | Union County, Iowa |
How does Twelve Mile Lake compare?
On nutrient and algae readings, Twelve Mile Lake runs above the Iowa state average. It ranks #2 of 6 lakes in Union County on nutrient and algae readings.
Water clarity (Secchi depth) sits at 2.4 feet. That signals heavy algae or sediment, often tied to high phosphorus from runoff. Algae levels (chlorophyll-a) measure 45 µg/L — elevated; risk of harmful algal bloom advisories increases at this concentration.
Stays via Stay22
Where to stay near Twelve Mile Lake
Compare cabins, hotels, and vacation rentals near Twelve Mile Lake in Union County, Iowa. Live availability and prices for your nights. Switch the map to Satellite to see how close each stay is to the water.
Top-rated places to stay near Twelve Mile Lake
Prices for Oct 23–25, 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 trip to Twelve Mile Lake?
Get lake water-quality updates plus the best cabin & lodging deals near Twelve Mile Lake — straight to your inbox. No spam, unsubscribe anytime.
Watch Twelve Mile Lake water quality
Get an email when the clarity or algae readings change. Unsubscribe anytime.