Water Resources Collections and Archives

Monitoring the ensuing morphological and vegetative change of river restoration projects has become evermore important as an increasing number of communities embrace such efforts. Numerous projects have succeeded in the short run and failed in the long run, but the success of a project can only be assessed through postproject monitoring efforts. A section of Tassajara Creek in Dublin California stretching roughly one mile was restored in 1999. The generalized goals of the project were to reconstruct the highly incised channel to accommodate for the 100 year discharge and to restore riparian habitat. A monitoring plan to document the effects of the implemented project was developed in 2001 accompanied by a series of eight cross-sections, a longitudinal profile, and photographs to begin the post-project evaluation. Between 2002 and 2003 four additional studies were conducted to continue the monitoring effort. All of these projects found some localized incision and aggradation. We took photographs of the riparian zone and resurveyed four of the cross-sections in the southern part of the restoration area and found evidence of aggradation of the thalwegs ranging from 0.25ft and 3.07ft at all sites following the first year of substantial flows. We also found evidence that suggests erosion and deposition along the floodplain terraces, but our results are inconclusive due to disparities in methodologies between our study and past studies. Regardless, our findings allow us to conclude that channel morphology may have been altered by the high flow events in 2004 and that restoration goals of improving riparian habitat are being met.