Bridgeport Reservoir, Lake Crowley positive for harmful algal blooms

Tests have confirmed harmful algal blooms at multiple locations in Mono County’s Lake Crowley and Bridgeport Reservoir, prompting the Lahontan Regional Water Quality Control Board to urge people and pets to stay out of the water.

The Lahontan Regional Water Board has posted a recreational “warning” advisory for the Old Marina Boat Ramp area and a “danger” advisory for areas near the dam and RV park to alert lake users of the elevated health risk.

Until the advisories are lifted, people visiting the lake should mind the following guidance:

Danger

• Stay out of the water until further notice, including watercraft.
• Do not let pets and other animals drink or go into the water, or go near the scum.
• Stay away from scum, and cloudy or discolored water.
• Do not eat fish from this water.
• Do not use this water for drinking or cooking. Boiling or filtering will not make the water safe.

Lahontan Regional Water Board staff monitored Lake Crowley on Sept. 24 and noticed visual signs near the South Landing area of the lake at both the Marina and the Hilton Creek Drainage. Sample results confirmed that toxin levels were present at dangerous levels at both locations.

Cyanobacteria, a group of organisms that form blooms, can produce potent toxins that can cause itching skin and rashes, as well as gastrointestinal distress, headaches, agitation and weakness, or abnormal breathing if is swallowed while swimming. Dogs and children are most susceptible to exposure because of their smaller body size, increased potential to swallow water while swimming and tendency to stay in the water longer. If you suspect exposure, wash your children and dog immediately.

The bloom occurring in the lakes appear suspended on the water’s surface. Bloom conditions can change rapidly, as the winds and waves move or concentrate the bloom into different regions of the lake. In some areas, the bloom may concentrate and form a film or scum on the water surface. The color of the water may also appear discolored as bright or dark green and brown.