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Updates
December 2, 2024: Harmful algal bloom (HAB) monitoring update
Recreational water quality monitoring has ended for the season. Monitoring will resume in summer 2025. A harmful algal bloom may still be present at this waterbody. Know what to look for and check before recreating.
October 24, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: Toxin concentrations have decreased during the last two sampling events. However, a harmful algal bloom is still present at Mantua Reservoir. Algae in the water may still be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
October 10, 2024: Harmful algal bloom (HAB) monitoring update
KEEP OUT: A harmful algal bloom is present at Mantua Reservoir. Algae in the water is producing high levels of dangerous toxins. Accidentally drinking this water may hurt or kill humans and animals. Any exposure to this water may cause illness.
Bear River Health Department has issued a DANGER ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Use caution if boating in this area and avoid areas of algae
- Use caution if fishing in this area
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
September 27, 2024: Harmful algal bloom (HAB) monitoring update
KEEP OUT: A harmful algal bloom is present at Mantua Reservoir. Algae in the water is producing high levels of dangerous toxins. Accidentally drinking this water may hurt or kill humans and animals. Any exposure to this water may cause illness.
Bear River Health Department has issued a DANGER ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Use caution if boating in this area and avoid areas of algae
- Use caution if fishing in this area
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
September 19, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Mantua Reservoir. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
August 29, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Mantua Reservoir. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
August 7, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present in some areas of Mantua Reservoir. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
July 30, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Mantua Reservoir. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
July 16, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Mantua Reservoir. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
July 10, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: A harmful algal bloom is present at Mantua Reservoir. Algae in the water may be producing dangerous toxins that can make humans and animals sick.
Bear River Health Department has issued a WARNING ADVISORY.
If you visit the Mantua Reservoir:
- Do not swim or water ski
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
July 3, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: Our monitoring team saw visible signs of a harmful algal bloom at locations throughout Mantua Reservoir. Algae in the water may be producing dangerous toxins.
If you visit Mantua Reservoir we recommend:
- Do not swim or water ski in areas of algae
- Avoid areas of algae when boating
- Clean fish well and discard guts
- Keep animals away
- Don’t drink the water
- Know how to recognize a harmful algal bloom
June 19, 2024: Harmful algal bloom (HAB) monitoring update
GOOD NEWS: Our monitoring team did not see any visible signs of a harmful algal bloom. Learn more about harmful algal blooms.
Site visited: Boat ramp, NE boat ramp near Indian Trail rd and Dike rd.
June 5, 2024: Harmful algal bloom (HAB) monitoring update
GOOD NEWS: Our monitoring team did not see any visible signs of a harmful algal bloom. Learn more about harmful algal blooms.
Site visited: Boat ramp, NE boat ramp near Indian Trail road and Dike road.