The purpose of the plan is to bring about coordinated physical development in accordance with the present and future needs of the county. The comprehensive plan shall be developed so as to conserve the natural resources of the county, to insure efficient expenditure of public funds, and to promote the health, safety, convenience, and general welfare of the public. Such comprehensive plan may include but not be limited to, among other things, studies and recommendations relative to the location, character and extent of highways, railroads, bus and other transportation routes, bicycle facilities, bridges, public buildings, public services, schools, parks, open space, housing quality, variety and affordability, parkways, hiking and riding trails, airports, forests, wildlife areas, dams, projects affecting conservation of natural resources, air quality, water quality and floodplain zoning.

Because the West Branch area has been left alone, it has a chance to recover and become a part of the larger Paseo de las Iglesias project, and a cornerstone of a more extensive effort at ecological restoration involving the mesic coorridors of Pima County, the Santa Cruz, Rillito, and Pantano.

“What about the water?” was one of the questions Morrison Institute for Public Policy asked in its 2008 study, "Megapolitan: Arizona’s Sun Corridor". That report looked at the potential growth of the Sun Corridor as Tucson and Phoenix merge into one continuous area for economic and demographic purposes.

With its brief review of the water situation in urban Arizona, "Megapolitan" left a number of questions unanswered. This report will consider questions like these in more detail in order to examine the Sun Corridor’s water future. This topic has received less sophisticated public discussion than might be expected in a desert state. Arizona’s professional water managers feel they are relatively well prepared for the future and would like to be left alone to do their job. Elected officials and economic-development professionals have sometimes avoided discussing water for fear of reinforcing a negative view of Arizona. This report seeks to contribute to this understanding, and to a more open and informed conversation about the relationship of water and future growth.