Division of Water Quality
Payson Lakes Recreational Monitoring
Payson Lakes consists of Big East Reservoir, Box Lake, and McClellan Lake and is located about 12 miles south of Payson in Utah County. DEQ’s recreational water quality monitoring checks for two health concerns: Harmful Algal Blooms (HABs) and Waterborne Pathogens (E. coli). Find the most recent monitoring information below.
Warning Advisory
Harmful Algae Present
- Do not swim or water ski
- Avoid areas of algae when boating
- Keep animals away
- Do not drink the water
- Clean fish well and discard guts
Updates
September 30, 2026: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Big East Lake and McClellan Lake. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
If you visit the area:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard skin and guts
- Keep animals away
- Don't drink the water
- Know how to recognize a harmful algal bloom
September 16, 2026: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Big East Lake and McClellan Lake. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
If you visit the area:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard skin and guts
- Keep animals away
- Don't drink the water
- Know how to recognize a harmful algal bloom
August 25, 2026: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Big East Lake and McClellan Lake. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
If you visit the area:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard skin and guts
- Keep animals away
- Don't drink the water
- Know how to recognize a harmful algal bloom
August 17, 2026: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Big East Lake. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
If you visit the area:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard skin and guts
- Keep animals away
- Don't drink the water
- Know how to recognize a harmful algal bloom
August 14, 2026: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: Our crew has observed a potentially harmful algal bloom at Big East Lake. There could be algae in the water producing dangerous toxins. We collected samples and results are pending. Check back here for updates.
In the meantime we recommend:
- Do not swim or water ski in areas of algae
- Avoid areas of algae when boating
- Clean fish well and discard skin and guts
- Keep pets and livestock away from the water and shoreline
- Don't drink the water
- Know how to recognize a harmful algal bloom
Site(s) sampled: Big East Lake Southwest Beach and Northwest Picnic Area Shoreline
June 23, 2026: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site(s) sampled: Big East Lake Southwest Beach and Northwest Picnic Area Shoreline