Fletcher on flood control

Historically, as the river flooded and meandered across the floodplain, the watershed boundary redefined itself.  Originally the river ran through a broad alluvial floodplain, the result of meandering dendritic flows that constantly redefined and disturbed the landscape and its ecologies…as late as 1872 a coast guard survey shows a continuous series of tidal estuaries, lagoons, mudflats and salt marshes from the mouth of the Los Angeles River east to the San Gabriel River.

David Fletcher, author Flood Control Freakology