Network (IMAGE) U.S. National Science Foundation Caption A network of levees and wetlands protect the low-lying agricultural communities in California's Sacramento-San Joaquin River Delta. Credit California Department of Water Resources Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.