Marsh Restoration
The restoration of a tidal marsh is a slow process, generally requiring one to two decades to complete (Rozsa 1995). Restoring a system by reintroducing tides is often complicated by a number of factors including indirect changes to the hydrology throughout the system and reductions in surface elevations within restricted tidal systems. The construction of multiple road crossings can significantly reduce the ability to reintroduce adequate tidal flushing to the site as inadequate and/or malfunctioning culverts limits the tidal prism upstream. Each successive bridge or crossing may then limit the salt water available to the system to be restored. For this reason, detailed hydrologic investigations are important in designing the vegetation restoration plan (see Milone and MacBroom 1996). In addition, many tidally restricted marshes presently dominated by common reed often experience subsurface compaction due to drying and high organic decomposition rates (Roman et al. 1984). Thus, when tides are reintroduced, some of the marsh areas are too low to support salt marsh grasses and convert to open water habitats. Although loss of elevation due to subsurface compaction at Sybil Creek may be of concern, at least in some areas, the addition of fill may have accelerated this compaction process.

In order to overcome some of the problems associated with marsh restoration, a number of alternative restoration techniques have been employed including innovative gate designs (i.e., self-regulating tide gates), the acquisition of low lying properties and multiple plant control techniques (i.e., mowing or burning of reed)(Rozsa 1995). The time frame to restore the system can be reduced by combining various techniques such as using reed control measures while increasing tidal flushing. However, these techniques can raise the cost of restoration, considerably.