Book Description
The Russian River Estuary (RRE) tends to trap salt that flows in from the Pacific Ocean when its mouth closes at multiple times each year. This closure leads to stratification and in some cases also flooding of local property. Different management strategies are being discussed, but here we focus on analyzing time evolution of salt mass through a set of six simulations that are each performed over a period of two months. The Biological Opinion, 2011, has specified a target condition for the river inflow and outlet elevation which is tested herein for a case of fast closure and slow closure, to observe the changes in density stratification in the RRE. A list of runs with changes to the target condition, are set up and their results analyzed. The results from this set of simulations show that, with respect to loss of salinity, the conditions with the highest outlet bed elevation (closed outlet), have the fastest loss of almost all the salt in the system within the given two-month time period. This is part of a broader effort to develop estuary management protocols that will yield improved habitat for juvenile steelhead (NMFS 2008). Through a subcontract to the Sonoma County Water Agency (SCWA), ESA and Philip Williams and Associates (ESA PWA) requested that the University of California Davis (UCD) perform this modeling study, which draws from the results of a separate but related field study conducted in the Russian River estuary during the summer-fall management season in 2009 (Behrens & Largier 2010, Largier & Behrens 2010).
