Self-regulating tidegates (SRTs) have been identified as functional infrastructure improvements for the restoration of marine and freshwater tidal wetlands in areas landward of levees and dikes where full restoration is not possible. The reintroduction of water, especially brackish and marine waters, into "reclaimed" land has raised concern regarding impacts to land uses landward of the dikes. It is possible that soil chemistry is altered with the reintroduction of tidal flow into historic channels. Changes in soil chemistry could improve, be detrimental to or not change land uses landward of the dikes. Surface and soil hydrology may also be affected with the introduction of tidal waters landward of the dikes. Again these impacts could improve, be detrimental to, or have no observable impact to the surrounding land uses. Observable differences in soil chemistry and hydrology will likely have a limited and quantifiable geographic scope. The quantification of the geographical impact of tidal wetland improvements is important to evaluate project boundaries.

Few studies have been conducted to validate whether SRT technology really does adequately allow fish passage, especially for juvenile salmon. Moreover, SRT applications can vary significantly in their design, application, and operation. These variables may influence fish passage effectiveness.

Therefore the primary research questions center around the following:
1. Does the replacement of standard tidegates with SRTs at the mouths of historic tidal sloughs change soil chemistry, surface water hydrology and ground water hydrology'
2. What SRT design, application, and operations effectively eliminate upstream and downstream blockages to fish migration'