The Foster City Public Works Department this week began raising the water level of the Foster City lagoon by six to eight inches to prepare for summer.

The lagoon’s levels are typically lowered in winter in case seasonal storms bring additional water. Levels are raised in the summer to accommodate recreational activities like sailing and windsurfing while making it harder for algae or other plants to grow.

Rainfall can raise the lagoon’s water levels or the Public Works Department can let water into the lagoon at high tide. The water level will be higher on weekends and holidays and lower in the middle of the week to promote maximum water exchange in the lagoon.

The city’s Lagoon Management Plan sets standards for these water levels. If major rainfall is forecast at any time of the year, the water level will be lowered once more to accommodate runoff and prevent flooding.

The lagoon, approximately 212 acres in size, acts as a drainage detention basin for the city, as storm water from the city flows into the lagoon and is pumped into the Bay. The lagoon can withstand a major storm likely to occur once a century.