1) wetland and vegetation habitat mapping and 2) rapid assessment of wetland condition using the California Rapid Assessment Method (CRAM) for wetlands at 40 sites, and 3) a more intensive biological survey of 26 sites including vascular plant and benthic macroinvertebrate community composition and bird use. Results of the survey showed that, while urban infrastructure provide some basic constraints on the achievable condition of wetland basins and channels, site-specific conditions can mitigate or exacerbate these constraints. The site-specific factors include, but are not limited to: 1) wetland size, 2) project objective and design criteria, 3) intensity of maintenance, and 4) origin of site.
We found that habitat wetlands could achieve what could be considered good condition if: 1) the sites can support wetland hydrology, 2) the hydrology can be managed to mimic natural hydroperiod, 3) the site is designed to have good physical structure, 4) the wetland and buffer have appropriate native vegetation, 5) the wetland is maintained frequently to manage stressors, but not in manner which is incompatible with the seasonal cycles of nesting and reproduction, and 6) issues of bioaccumulation and toxicity are not a factor. This last factor has not been evaluated as a part of the baseline biological survey, but will be addressed in the subsequent phases of the project.