”Carrying Capacity”: What Does It Mean?

The concept of “carrying capacity” means that there are limits on available infrastructure to sustainably support future population increases and activities.  With regard to water, because of the Congressional Raker Act, San Francisco has access to the Tuolumne River without the constraints placed by the state or federal government on users whose water flows through the Delta.  If Hetch Hetchy were torn down and SF waived its water rights to the Tuolumne, then “San Francisco’s water” would become part of the statewide system, with all its problems, and that seems very unlikely.  In essence, San Francisco already has its own private peripheral canal. Nevertheless, because San Francisco does share its water supply with other Bay Area cities, and because even Hetch Hechy’s supplies are limited, there are constraints on San Francisco’s water supply.  There are also limits on SF sewer treatment, electrical supplies, and roadway capacity.  All these elements would be taken into account if San Francisco were seriously interested in determining a sustainable carrying capacity.