This document presents common and statutory water laws for Maryland and Virginia and legal concepts of water law in the U.S., including water courses, surface or diffused waters, and subsurface waters. Determination of water rights is increasingly affected by Federal and State legislative enactments. Statutory laws enacted by Congress have empowered the Federal Goverment to carry out water conservation, pollution abatement, and flood control projects under commerce, national defense, and welfare powers granted by the Constitution. Constantly changing environmental and technological circumstances, too rapid for common law development, have resulted in the growth of statutory water law.