Mantua Reservoir Recreational Monitoring - Utah Department of Environmental Quality

Looks Good!

Icons for safe to swim, safe to boat, safe to eat fish. Although doing all 3 at the same time might be challenging.

There are no current health advisories for this water body.

Conditions may change quickly. Check before entering the water and know how to spot a harmful algal bloom.

Mantua Reservoir is located in Box Elder County, approximately 5 miles east of Brigham City, at the edge of the town of Mantua. DEQ’s recreational water quality monitoring checks for two health concerns: Harmful Algal Blooms (HABs) and Waterborne Pathogens (E. coli). We post monitoring updates on this page as soon as we can, but our map (also found on HABs.utah.gov) will always have the most recent information.

Updates

June 12, 2025: 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.

Sites visited: Boat ramp, NE near Indian Trail road and Dike road.