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Bay Modeling Projects

 

South San Francisco Bay Salt Pond Restoration Initial Stewardship Plan

 

Cargill Salt

 

The South Bay Salt Pond Restoration Project is the largest tidal wetland restoration project on the West Coast. The Cargill Corporation as well as the California Department of Fish and Game and the U.S. Fish and Wildlife Service initiated the development of an Initial Stewardship Plan (ISP) for the transfer of ownership and management of a portion of the existing salt ponds in South San Francisco Bay from Cargill to the wildlife agencies. The overall land transfer includes 16,100 acres while the ISP area encompasses approximately 15,100 acres. The goals of the ISP project are to cease commercial salt production, to maintain high quality wetland and wildlife habitat, to introduce tidal hydrology in the ponds where feasible and to preserve the ponds in condition suitable for long term restoration.

 

The ISP Project team included Schaaf & Wheeler, Dr. Steve Hansen, Dr. Edward Gross, and Dr. Michael MacWilliams.  Schaaf & Wheeler was responsible for project management and the design of pond infrastructure; Dr. Hansen was responsible for biological analysis.  The hydrodynamic modeling effort was directed by Dr. Edward Gross with assistance from Dr. MacWilliams.

 

The ISP modeling effort included the development of a pond operation model for each pond group and three-dimensional simulations of South San Francisco Bay and associated tidal sloughs, including Alviso Slough, Coyote Creek, and Alameda Flood Control Channel.  The pond operation model was used to determine the appropriate connectivity of ponds in each system and sizing and placement of flow structures.  The model was then used to predict salinity in the pond systems for the initial release and for interim operations.  The pond model was coupled with the three-dimensional simulations of South San Francisco Bay to predict the effects of the initial release and interim operations on salinity and hydrodynamics in South San Francisco Bay.  Detailed simulations were made Alviso Slough, Coyote Creek, and Alameda Flood Control Channel.

 

Tidal action will be restored to at least three ponds, known as the Alviso Region Island Ponds, as part of the ISP. Three-dimensional simulations of this tidal restoration project were performed to estimate effects on tidal hydrodynamics and salinity.

 

The Initial Stewardship Plan was approved by the San Francisco Regional Water Quality Control Board on March 17, 2004.  ISP releases from the ponds began in April 2004; additional releases occurred in the summer of 2004 and in March 2005 and the Island Ponds will be restored to tidal action in 2006 .  The ISP continues to serve as a management guideline for pond operations while the long-term restoration plan is being developed.  

 


Three-Dimensional Hydrodynamic Modeling of the San Francisco Estuary: Toward Understanding the Mechanisms Relating Flow to Abundance of Estuarine Biota

 

CALFED Bay-Delta Program & San Francisco State University

 

Freshwater flow to the San Francisco Estuary is regulated in part using a salinity standard based on “X2,” the position of the 2 psu isohaline. The standard is based on the “fish-X2” relationships, by which abundance or survival several of estuarine species is higher when X2 is seaward and flow is high. The X2 standard is a rare example of ecosystem management, but it is a crude tool for managing ecosystem protection.

 

The CALFED Bay-Delta Program funded a multi-year interdisciplinary research effort to investigate the mechanisms relating flow to abundance of estuarine biota.  This effort includes initial modeling studies using existing field data to identify important mechanisms and guide in the planning and design of a concentrated field research and modeling effort in subsequent stages of the project.  The project is a collaborative effort between Dr. Wim Kimmerer (SFSU, Tiburon), Dr. Bill Bennett (Bodega Marine Lab), and Dr. Edward Gross.  Additional modeling support was performed by Schaaf & Wheeler and Dr. Michael MacWilliams.

 

A three-dimensional hydrodynamic model was applied to San Francisco Bay, San Pablo Bay, Suisun Bay and the western Sacramento-San Joaquin Delta to improve understanding of salinity transport mechanisms.  The model was calibrated and validated against current meter and salinity data including velocity profile and salinity transect data.  Simulation results were used to investigated tidal time scale hydrodynamics including the formation and destruction of vertical stratification.  Residual velocities and salt transport mechanisms in Carquinez trait and Suisun Bay were also analyzed.

 

Ongoing modeling efforts are aimed at understanding the spatial distribution of salinity, and the effect of varying freshwater flow and X2 on retention of estuarine organisms. The resulting research program will provide CALFED with vital information needed for long-term management and restoration of the estuarine ecosystem.


 

Hydrodynamic and Sediment Transport Modeling of the Impact of Proposed Runway Extensions for the San Francisco International Airport

 

URS Corporation

 

The most comprehensive hydrology and sedimentation study every conducted on San Francisco Baywas performed as part of the planning process for potential runway configuration at the San Francisco International airport. The study included collection and analysis of an extensive set of field data and development and application of sophisticated computer models to estimate the physical and ecological effects of various runway configurations, sediment borrow sites and mitigation sites. The detailed studies were documented and underwent review from a panel of experts convened by NOAA.

 

As part of URS project team, Dr. Edward Gross provided advice and guidance on hydrodynamic model calibration and validation and performed the three-dimensional hydrodynamic modeling portion of the project. Dr. Gross had a large role in model calibration and validation of the hydrodynamic models. This work included oversight of generation of the bathymetric model grid of San Francisco Bay, identification of calibration and validation datasets and development of the methodology for hydrodynamic model calibration and validation. He interacted regularly with URS staff and DHI to improve the calibration and validation of the MIKE21 model and provided advice and review related to many aspects of the two-dimensional hydrodynamic, sediment transport and water quality simulations.

 

In the process of performing three-dimensional modeling for the project, Dr. Gross improved the numerical method of the three-dimensional TRIM3D model and extended its input/output capabilities. He calibrated the model using a large set of hydrodynamic data including velocity profile data, salinity transect data, continuous salinity data, mechanical current meter data and tidal elevation data.

 

The calibrated and validated hydrodynamic models were applied to estimate the physical effects of combinations of several runway alternatives, sediment borrow sites and mitigation alternatives. A large number of MIKE21 simulations performed by URS to identify preferred alternatives. Three-dimensional hydrodynamic simulations of preferred alternatives were performed by Dr. Edward Gross using the TRIM3D model. Model predictions were used in evaluations of potential ecological effects of project alternatives.

 

 

Copyright © 2005

Edward Gross