Abstract
“Reliable water supply” does not have a clear definition in the
Western United States, where water resources are limited and such a
definition would be especially useful. In Utah, the three water agencies
and 500 public water systems have no consistent method to define,
evaluate, and report it, potentially leading to an inability to meet
regulatory water demands. We propose a unified definition of reliable
water supply for Utah’s public water suppliers that can also be used
elsewhere. The qualitative definition we propose is necessary to precede
quantitative evaluations, set policy, and provide consistency to water
resources management. We derive our definition from a two-part
qualitative analysis: 1) an extensive review of existing definitions in
industry and academia and 2) semi-structured interviews with managers of
six diverse Utah water utilities. We propose that water supply be
defined by three overlapping components—hydrology, infrastructure, and
governance—and that reliability be defined by the capacity of the
limiting component.