STORAGE-RELIABILITY-RESILIENCE-YIELD RELATIONS FOR NORTHEASTERN UNITED-STATES

An evaluation of time-series of streamflow at 166 basins in the northe astern United States reveals that this region is remarkably homogeneou s in terms of the year-to-year variability and persistence of average annual streamflow. Goodness-of-fit tests reveal that the 166 time-seri es of annual streamflow tested were well approximated by a lag-one nor mally distributed autoregressive process with a fixed lag-one correlat ion and a fixed coefficient of variation. Computer experiments reveale d that the observed variability about these fixed values could easily arise from sampling alone, due to the varied and short records availab le. Recent research an the behavior of water supply systems reveals th at simple analytic models can describe the general relationships among reservoir storage, yield, reliability, and resilience for systems dom inated by overyear storage requirements. An analytic storage model is combined with the regional model of annual streamflow, resulting in ge neral relations among storage, reliability, yield, and resilience usef ul for water supply systems in the Northeast. An example using the wat er supply systems for New York City, Boston, Providence, Rhode Island, and Springfield, Massachusetts, documents how-the proposed: methodolo gy may be used to compare the behavior of four very different systems.