A WATER BUDGET STUDY OF PUGET SOUND AND ITS SUBREGIONS1

Abstract

A water budget study for Puget Sound and its principal subregions, based on the freshwater, seawater, and total water budgets, determines the mean fluxes of water into and out of these regions, the freshwater content, and the change in freshwater content by month and by year. Data used to calculate the budgets include monthly mean values of precipitation, evaporation, runoff, changes in sea level, mean salt content, and the salinities of inflowing and outflowing waters for each subregion. The fluxes of water calculated in the budget analysis yield an approximation of flushing efficiency and replacement time for Puget Sound and its subregions. The monthly freshwater content, along with the fluxes of water and their salt load, indicates that river runoff does not by itself control the freshwater content of a particular subregion; considerable freshwater is added by the inflow of water from an adjacent embayment.