This publication consist of two parts exclusively covering the Island of Oahu, definted by the Koolau and Waianae ranges. Part 1 (1-198) is concerned with topics related to geology and part 2 (199-467) is concerned with topics related to ground water resources. The geology pertains to the Waianae volcanic series, Kailua volcanic series, Koolau volcanic series and the Honolulu volcanic series. The study covers climate generated water, surface water, ground water, and access to these water sources.