Mendenhall provides a comprehensive overview of the geology, hydrology, and irrigation practices in the foothill belt of Southern California. He examines the various types of groundwater resources in the region, as well as the challenges and opportunities associated with developing them for agricultural and urban uses. Mendenhall's work is a valuable resource for anyone interested in California's water resources and the management of irrigation enterprises. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.