Four Island Lake Caution


Lake Quality Advisory Committee Update

On August 29th and 30th a Lake management biologist joined the LQAC to analyze and assess our lake conditions. We are all disappointed that our lake has had a harmful algal bloom (HAB) when the weather is hot, and we would love to be enjoying our lake. The LQAC survey indicated the top priorities of residents are water quality, a natural environment, and a sustainable strategy. The biologist examined the watershed in the valley, Four Island Lake, Cub Lake, Jack's Hole, 7th Hole Pond, and provided suggestions and future resources and help for a natural sustainable road to better water quality. He reviewed our current data, took additional readings, and examined ditches, golf course irrigation, use of effluent and potential runoff from the transfer center roads and other areas around the lakes. An important observation he made was the complete lack of aquatic plants in any of the water bodies currently; Four Island, Cub and Jack's Hole have no healthy plant growth within the water. The nutrient loading is not only heavy, it is out of balance with extremely high phosphate. This imbalance prevents healthy plant growth and promotes the growth of cyanobacteria that produce toxic algal blooms and skew the fish populations, favoring Bullhead Catfish. The biologist validated that these imbalances have been produced over a long period of time and will not be reversed or remediated instantly - but will take time to repair. Unfortunately, he also explained from his experience that without intervention we will see more harmful blooms in greater frequency. The plans going forward need to begin with nutrient control and will require a treatment to bind phosphate and add fresh water to the lake to dilute current conditions. Phase two includes balancing and controlling fish populations and re-introducing aquatic plants. To sustain a pathway to good water quality the entire valley will need to commit to reducing the use of fertilizer and Roundup associated with runoff into the lake, reduce the use of high phosphate detergents and soaps, and clean up animal manure that contributes to nutrients in runoff. On a much broader basis, and requiring collaboration of many groups in the valley, we need to redirect effluent away from the lake, closely manage fertilizer and run-off on the golf course, maintain vegetation to filter runoff, and increase fresh water flow from the non-potable wells into the lake. These measures will take time and commitment, but based upon the value of the lakes, this focus is one shared by most residents. We are closely monitoring the lake so that we can alert people when the toxin is dissipated, and the water is safe. BVSA residents will always be able to log into the California HAB website (  for water conditions which are posted immediately if there is a concern or problem regarding safety. We also intend to have a virtual town hall about the lake water quality before the end of September.

For technical questions and comments regarding this website,
please contact the Webmaster.