Here is a view from above of part of the area.
Shortly after I arrived in Tuscon, Az. in 1963 I had a conversation with our neighbor on the corner, who was a hydrologist. He informed me that in the 19th century the water table was at the surface in a great many of the streams and rivers in the area, such as the Santa Cruz, but that by 1963 the City of Tuscon was pumping fossil water from beneath the valley to the west of the Tuscon Mountains, which were the western edge of the city in those days, when the population was ~125,000. The population today is >500,000 and the Central Arizona Project, which was intended to provide an alternative to groundwater pumping, feeds water from the Colorado River, below Hoover Dam. Tuscon has long encouraged low water residential and municipal landscaping, but possibly could better utilize surface run-off from the 10-14" annual rainfall.
A complicating factor is that various records going back hundreds of years, pollen in sediment, tree-ring data, etc, shows that there have been prior episodes of very long El Nino type weather patterns. I love Tuscon and LA, have family in Tuscon and friends in LA but am glad I don't own property in either city, or in Vegas. As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."
Tucson has been continuously settled for over 12,000 years.... Tucson, too SAHN or TOO sahn, is one of the oldest towns in the United States. Tucson was originally an Indian village called Stook-zone, meaning water at the foot of black mountain. Hugo O'Conor established the Tucson Presidio in 1775. August 20th, 1775 is considered Tucson's birthday. Spanish settlers arrived in the area in 1776. Tucson officially became part of the United States with the Gadsden Purchase of 1854. Tucson served as capital of the Arizona Territory from 1867 to 1877.
