With the Sacramento River to its west, and the American River to the south, the Natomas Basin sits at the confluence of two major waterways. Streams, creeks and tributaries mark the northern and eastern boundary. Water surrounds the basin’s perimeter. Levees help keep flowing waters in their channels and out of growing neighborhoods, where approximately 100,000 people live, but a breach to any section of the 42 miles of levee surrounding Natomas could be catastrophic.