When a breech occurred in a levee on Upper Jones Tract Island near Stockton last year, ten million dollars of property and farmland were destroyed.

A regional environmental organization, Baykeeper says a breech this weekend or even the possibility of one could not only threaten more property, it could result in the contamination of the local water supply.

Spokeswoman Carrie McNeil says a health risk occurred last year following the breech on Upper Jones Tract Island.

"Contaminated soils were actually used to help bolster the levees, which clearly is a huge problem for water quality and the health of this whole area."

There is also concern in the Stockton area about the residential development in the floodplain. Those who live in the vulnerable areas are leading the call for the state to make sure the levees are strong enough to withstand heavy rain or an earthquake.