The SONGS Coastal Development Permit requires that monitoring of the wetland restoration be done over the full operating life of SONGS Units 2 & 3 in order to ensure that the restoration project is successful. In accordance with the SONGS Permit, CCC contract scientists developed a SONGS Wetland Mitigation Monitoring Plan to guide the monitoring work. The Monitoring Plan includes a description of each performance standard used to evaluate the success of the restoration project and the methods that will be used to determine whether the various performance standards have been met.

The performance standards can be classified into absolute and relative standards. Absolute standards are evaluated solely at the San Dieguito Wetlands (SDW) restoration. Relative standards are evaluated through a comparison of the similarity of values in the restored wetland to values in the reference wetlands. In order to select reference wetlands, we assembled a list of over 40 coastal wetlands and evaluated them using 3 criteria specified in the SONGS Permit, which require that the reference wetlands be 1) relatively undisturbed, 2) natural tidal wetlands, and 3) located in the Southern California Bight. The wetlands selected for reference using these criteria were Tijuana River Estuary, Mugu Lagoon, and Carpinteria Salt Marsh.

The performance standards for the wetland restoration project can also be classified into physical and biological standards. Physical standards pertain to topography (erosion, sedimentation), water quality (i.e, oxygen concentration), tidal prism, and habitat areas. Biological standards pertain to biological communities (e.g., fish, invertebrates, and birds), cover of marsh vegetation and macroalgae, Spartina canopy architecture, reproductive success of marsh plants, food chain support functions, and exotic species.

The physical and biological performance standards used to evaluate the success of the San Dieguito Wetlands Restoration project are given below.

Physical Standards

  1. Topography. The wetland shall not undergo major topographic degradation (such as excessive erosion or sedimentation).
  2. Water quality. Water quality variables shall be similar to reference wetlands
  3. Tidal prism. The designed tidal prism shall be maintained, and tidal flushing shall not be interrupted
  4. Habitat areas. The area of different habitats shall not vary by more than 10% from the areas indicated in the final restoration plan

Biological Standards

  1. Biological communities. Within 4 years of construction, the total densities and number of species of fish, macroinvertebrates and birds shall be similar to the densities and number of species in similar habitats in the reference wetlands.
  2. Vegetation. The proportion of total vegetation cover and open space in the marsh shall be similar to those proportions found in the reference sites. The percent cover of algae shall be similar to the percent cover found in the reference sites.
  3. Spartina canopy architecture. The restored wetland shall have a canopy architecture that is similar in distribution to the reference sites, with an equivalent proportion of stems over 3 feet tall.
  4. Reproductive success of salt marsh plants. Certain plant species, as specified in the work program, shall have demonstrated reproduction (i.e. seed set) at least once in three years.
  5. Food chain support. The food chain support provided to birds shall be similar to that provided by the reference sites, as determined by feeding activity of the birds.
  6. Exotic species. The important functions of the wetland shall not be impaired by exotic species.