California recognizes many types of water rights. Prior to the Treaty of Guadalupe Hidalgo, signed in 1848, California was part of Mexico. Riparian rights were the most prevalent type of water right. Under riparian rights, which have their origins in Roman law, a landowner can use water flowing by his property for use on his property. When California became part of the United States, the United States agreed to recognize existing law. Pueblo rights were the only vested water rights at the time. Pueblo rights provided that Spanish and Mexican pueblos were entitled to the paramount beneficial use of all needed naturally occurring water from the entire watershed of a stream flowing through the pueblo.