SummaryCumulative hydrostatic force on levees and other flood-control structures. This is a measure of the calculated force that rivers in flood put on segments of levee, which can highlight areas vulnerable to failure under certain flood conditions. General Information about this IndicatorWhat is it?: This indicator was proposed during a CALFED-sponsored review of the Delta levees program (Mount and Twiss, 2004). It represents the calculated force that rivers in flood put on segments of levee.