SONGS coastal view
 

Mitigation Projects > Wetland > Restoration Monitoring

[Wetland] Restoration Monitoring

  • Pre-Construction
  • Construction
  • Post-Construction
 

Pre-Construction Monitoring

The SONGS Permit establishes physical and biological performance standards that must be met by the restored wetland for the project to be considered successful and it requires monitoring before, during, and after construction of the restored wetland. The purpose of pre-construction monitoring was to obtain data necessary to develop a rigorous but cost-effective sampling program for evaluating the success of the restored wetland post-construction. We conducted pre-construction monitoring studies at SDL and other southern California wetlands, including those that will be used as reference sites in post-construction monitoring.

     
       
  pickleweed sicklegrass  
  Pickleweed (Salicornia virginica=Sarcocornia pacifica), a common native plant found in Southern California salt marshes.   Patch of salt marsh-upland transition invaded by the non-native sicklegrass (Parapholis incurva).
 

SCE receives mitigation acreage credit for the restoration of tidal wetland. During pre-construction monitoring, we developed a definition of “tidally influenced” habitat for planning purposes and for evaluating compliance of the project with the SONGS Permit. The goal of the restoration is to produce a naturally functioning wetland that is vegetated with native species, such as pickleweed (Salicornia virginica = Sarcocornia pacifica), as opposed to exotic invasives, such as sicklegrass (Parapholis incurva). We examined the lower tidal elevation limit of sickle grass and upland species at a sites in Carpinteria Salt Marsh, Tijuana Estuary, Mugu Lagoon and San Dieguito Lagoon and found that this limit varied among sites due in large part to varying degrees of tidal muting and, at SDL, tidal run-up (Page et al. 2003). However, at SDL, the boundary between native and exotic and upland plants generally occurred lowest at around +4.5’ NGVD (National Geodetic Vertical Datum = Mean Sea Level in 1929) (= 7.06’ Mean Lower Low Water, MLLW). Thus, this elevation served to define the upper limit of tidally influenced habitat for this project and SCE will receive mitigation credit for acreage restored at and below this elevation.

     
         
  Researcher deploying beach seine and blocking net   gobies sampled using exposure traps  
  Deploying a beach seine and blocking net to sample wetland fish at San Dieguito Lagoon.   The most numerous fish in San Dieguito Lagoon are gobies which are best sampled using enclosure traps that were developed during pre-restoration monitoring.  
 

Physical and biological data on the wetland attributes to be monitored during post-construction monitoring were collected to assist in developing sampling designs for evaluating the various performance standards have been met. A principle focus of this work was on developing effective methods for sampling wetland fish, which can be highly mobile and variable in abundance and thus difficult to adequately sample (Steele et al. 2006a,b, 2007).

The results of all pre-construction monitoring studies on fish, invertebrates, birds, vegetation, and water quality are incorporated into the Wetland Monitoring Plan for SONGS Mitigation.

     
     
     
  UCSB biologist assessing impacts
  UCSB biologist assessing potential impacts to existing vegetation caused by construction of the restored wetland at San Dieguito Lagoon.  

Construction

The SONGS Permit requires independent monitoring to ensure that the restoration work is conducted according to approved plans. To accomplish this task, we conduct routine monitoring of planned construction activities and field inspections of work in progress. We also monitor the impacts of unplanned construction activities and work cooperatively with SCE in the assessment of the suitability of seasonal wetland habitat for mitigation of project permanent impacts to seasonal wetland.

 

Post-Construction

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 insure that restoration project is in compliance with the specified performance standards. In accordance with the Permit, we developed a Wetland Monitoring Plan to guide the monitoring work. The Monitoring Plan includes a description of each performance standard and the methods that will be used to determine whether the various performance standards have been met.

     
         
  installing an environmental data logger purse seine deployed from a small boat  
  Installing an environmental data logger to monitor water quality in the river channel of the San Dieguito Lagoon.   Wetland fish in the main channels and basins of the restored and reference wetland are sampled using a purse seine deployed from a small boat.  
 

The performance standards for the wetland restoration identified in the SONGS Permit are of two types. The first type includes long-term physical standards that pertain to topography (erosion, sedimentation), water quality (e.g., oxygen concentration, salinity, temperature), tidal prism, and habitat areas. The second type includes biological performance standards that pertain to biological communities (e.g., fish, invertebrates, and birds), cover of marsh vegetation and bare space, Spartina canopy architecture, reproductive success of marsh plants, food chain support functions, and exotic species.

     
         
  aerial view of Tijuana estuary   aerial view of Mugu Lagoon  
  Aerial view of Tijuana Estuary showing dendritic tidal creeks.   Aerial view of Mugu Lagoon.  
  aerial view Carpinteria Salt Marsh  

The performance standards can further be classified into those that will be evaluated solely at SDL using criteria fixed in the SONGS Permit, and those that will be evaluated through a comparison of the similarity of values in the restored wetland to reference wetlands. These "relative" standards include those that pertain to water quality, biological communities, vegetation, Spartina canopy, and reproduction of marsh plants. 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.

 
  Aerial view Carpinteria Salt Marsh.