Search all of DEQ Main Menu Utah Department of Environmental Quality
Secondary Navigation

Rockport Reservoir Algal Bloom 2017

| Updates | Data | Photo Gallery |

Rockport Reservoir, sometimes known as Wanship Reservoir, is about three miles long and one-half mile wide and covers more than 500 acres. The state park is a popular recreation site for boating, fishing and water sports. The 6,000-foot-elevation reservoir was created by the Wanship Dam in the 1950’s.

Update August 22, 2017

Division of Water Quality (DWQ) scientists observed an algal bloom on the reservoir on August 15, 2017. The bloom appeared to cover 25-35 percent of the reservoir, was concentrated at the western beach, and was present at the beach area near the marina. Characteristic algal-bloom streaks were observed lake-wide. DWQ staff collected water samples and conducted toxin strips tests. The toxin strip tests came back non-detect for anatoxin-a, microcystin, and cylindrospermopsin.

The Summit County Health Department and DEQ’s Division of Drinking Water have been notified about the bloom.

Sampling Date, Locations, and Cyanobacteria Cell-Count Concentrations

August 15, 2017

DWQ scientists collected four samples across the reservoir. The dominant cyanobacteria genus found in the samples was Aphanothece, which the literature suggests is not a cyanotoxin producer. Cell-count densities were considerably lower above the reservoir than within the reservoir.

  • Rockport Reservoir at marina: 34,467 cells/milliliter (cells/ml)
  • Rockport Reservoir at west side beach: 23,273 cells/ml
  • Weber River above Rockport Reservoir: 2,109 cells/ml
  • Smith and Morehouse Reservoir at boat ramp: 34,510 cells/ml


Strip tests came back non-detect for anatoxin-a, microcystin, and cylindrospermopsin.