VERNALIS -- The San Joaquin River at Vernalis is forecast to rise above flood stage of 29 feet Thursday afternoon, near danger stage of 29.5 feet.
Flood stage doesn't necessarily mean widespread flooding is imminent, but it does mean levees will be strained and there is a higher risk of levee failure.
Danger stage is reached when a river is within a foot of the top of a levee.
"It means that the water is at a critical height, and it's being monitored very very closely," explained San Joaquin County emergency planner, Jenny Rich.
The county's Office of Emergency Services has set up a mobile command center at its headquarters to handle any emergencies that develop as the rivers run high.
In some neighborhoods especially close to the San Joaquin River, damage has already been done. Residents in the Haven Acres community in Lathrop have been moving their belongings to higher ground as flood waters have reached their garages and foundations. Authorities with the Lathrop-Manteca Fire District are patrolling the area.