Looks Good!
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.
Sand Hollow Reservoir is located approximately 9 miles west of Hurricane in Washington 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.
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Updates
May 5, 2025: 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 sampled: Sand Hollow State Park, south of the boat ramp and at the day-use beach
December 3, 2024: Harmful algal bloom (HAB) monitoring update
Following treatment, no harmful algae mats were observed at Sand Hollow Reservoir.
Recreational water quality monitoring has now ended for the season. Monitoring will resume in summer 2025. Know what to look for and always check before recreating.
November 4, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: Harmful algae mats are present in some areas of Sand Hollow Reservoir. Mats may be green, brown, or black in color. They appear as thick, mucous-like patches that may detach and float along the water surface or accumulate near the shore. These mats may be producing toxins that can hurt humans and animals if mat material is ingested.
Washington County Water Conservancy District and Sand Hollow State Park have posted Warning Advisory signage.
If you visit Sand Hollow Reservoir, we recommend:
- Do not swim, play, or submerge your head in areas with floating algae mats
- Children and dogs should be kept away from areas with visible harmful algae mats
- Do not drink the water
- Know how to recognize harmful algae mats and the symptoms of harmful algae exposure
October 23, 2024: Harmful algal bloom (HAB) monitoring update
BE CAREFUL: Harmful algae mats are present in some areas of Sand Hollow Reservoir. Mats may be green, brown, or black in color. They appear as thick, mucous-like patches that may detach and float along the water surface or accumulate near the shore. These mats may be producing toxins that can hurt humans and animals if mat material is ingested.
Washington County Water Conservancy District and Sand Hollow State Park are posting Warning Advisory signage.
If you visit Sand Hollow Reservoir, we recommend:
- Do not swim, play, or submerge your head in areas with floating algae mats
- Children and dogs should be kept away from areas with visible harmful algae mats
- Do not drink the water
- Know how to recognize harmful algae mats and the symptoms of harmful algae exposure
Monitoring is ongoing and updates will be shared on this page.
October 15, 2024: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below Utah Department of Health recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site sampled: South of boat ramp, day use beach
September 9, 2024: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below Utah Department of Health recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site sampled: South of boat ramp, day-use beach
August 21, 2024: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below Utah Department of Health recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site sampled: South of boat ramp, day use beach
July 30, 2024: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below Utah Department of Health recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site sampled: South of boat ramp.
June 18, 2024: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below Utah Department of Health recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site sampled: South of boat ramp, day use beach
May 29, 2024: Waterborne pathogen (E. coli) monitoring update
GOOD NEWS: E. coli counts were measured below Utah Department of Health recreational thresholds. Sampling suggests that the water is safe from harmful bacteria and viruses.
Site sampled: South of boat ramp, day use beach