Sfbaymodel Jun 2026

San Francisco Bay Delta Model. ... The San Francisco Bay Delta Model Regional Visitor Center (BMVC) is located in the city of Saus... San Francisco District, U.S. Army Corps of Engineers (.mil) The Bay Model Journey The Bay Model Journey. The Bay Model is a three-dimensional hydraulic model of San Francisco Bay and Delta areas capable of simula... San Francisco District, U.S. Army Corps of Engineers (.mil) Bay Model Visitor Center - Landmarks Bay Model Visitor Center * The Bay Model Visitor Center is a fully accessible education center administered by the U.S. Army Corps... Marin Convention & Visitors Bureau The Technical Side of the Bay Model As the mission of the Bay Model moves away from scientific research and more toward interpretation and education, the associated V... San Francisco District, U.S. Army Corps of Engineers (.mil) The Bay Model; a Cool Thing | Deeds & Words Jan 10, 2015 —

The San Francisco Bay Model (SF Bay Model), located in Sausalito, California, is a massive three-dimensional hydraulic engineering tool that serves as a working scale model of the San Francisco Bay and Sacramento-San Joaquin River Delta. This 1.5-acre scientific instrument was originally designed to simulate tides, currents, and water flow to test major infrastructure proposals before the advent of modern computer modeling. 1. Executive Summary: Purpose and Origin Original Goal: Authorized by the Rivers and Harbors Act of 1950, the model was completed in 1957 by the U.S. Army Corps of Engineers (USACE) primarily to evaluate the Reber Plan . The Reber Plan: Proposed by John Reber, this plan suggested constructing two massive dams across the San Francisco Bay to create freshwater lakes for irrigation and industrial use. Testing on the Bay Model proved the plan would have caused catastrophic ecological damage and flooding, leading to its rejection. Status Today: Decommissioned as a primary research lab in 2000, it now operates as the Bay Model Visitor Center , a premier educational and STEM facility. 2. Technical Specifications The model is a highly precise scientific instrument that uses a combination of concrete and copper to replicate complex water dynamics. History of the Bay Model

Report on the San Francisco Bay Simulation Model (SFBayModel) 1. Executive Summary The San Francisco Bay Simulation Model (SFBayModel) is a high-resolution, three-dimensional hydrodynamic and transport model of the San Francisco Bay-Delta estuary. Developed primarily for understanding and predicting water circulation, salinity intrusion, sediment transport, and the dispersal of waterborne constituents (e.g., pollutants, larvae, heat), it serves as a critical tool for water resource management, environmental restoration, and regulatory compliance in one of the most complex and economically significant estuaries in the world. 2. Introduction & Background The San Francisco Bay-Delta system (including Suisun Bay, San Pablo Bay, Central Bay, and South Bay) is the largest estuary on the Pacific Coast of the Americas. It supplies drinking water to over 27 million California residents, supports billions of dollars in agriculture, and provides critical habitat for numerous threatened and endangered species (e.g., Delta smelt, Chinook salmon). Given the system’s sensitivity to freshwater inflow from the Sacramento and San Joaquin Rivers, tidal forcing from the Pacific Ocean, and human alterations (dams, levees, water diversions), a numerical model is essential for:

Predicting salinity intrusion under varying river flow and sea-level rise scenarios. Assessing the impacts of proposed water projects (e.g., California WaterFix, Delta Conveyance Project). Guiding pollutant discharge permits (e.g., from municipal wastewater treatment plants). Designing wetland restoration projects. sfbaymodel

3. Model Framework & Technical Specifications The SFBayModel is most commonly implemented using the UnTRIM (Unstructured Tidal, Residual, Intertidal Mudflat) or SUNTANS (Stanford Unstructured Nonhydrostatic Terrain-following Adaptive Navier-Stokes Simulator) codes, though other versions exist (e.g., Delft3D, ROMS). 3.1 Key Features | Feature | Specification | |--------|----------------| | Domain | Entire San Francisco Bay-Delta (from Rio Vista to Golden Gate) | | Grid type | Unstructured (triangular/quads) – allows high resolution in channels and shallow flats | | Horizontal resolution | 20–500 m (finer in channels, coarser in deep basins) | | Vertical layers | 10–20 sigma (terrain-following) or hybrid coordinates | | Tidal forcing | M2, S2, N2, K1, O1 constituents (from TPXO or observations) | | River inflows | Daily to hourly from USGS gauges (Sacramento, San Joaquin, local creeks) | | Meteorology | Hourly wind, pressure, heat flux (from CIMIS or NAM) | 3.2 Governing Equations The model solves the Reynolds-Averaged Navier-Stokes (RANS) equations with the Boussinesq and hydrostatic approximations (though non-hydrostatic options exist for localized flows). Salinity and temperature are transported as passive (but density-influencing) scalars.

Continuity: ∇·u = 0 Momentum: ∂u/∂t + (u·∇)u = -∇p/ρ₀ + ν∇²u + f·k×u + F_tide Transport: ∂C/∂t + ∇·(uC) = ∇·(K∇C) + sources/sinks

3.3 Calibration & Validation SFBayModel is rigorously calibrated against: San Francisco Bay Delta Model

Tidal elevation (NOAA gauges at Alameda, Richmond, Redwood City, etc.) – RMS error typically < 5 cm. Salinity (long-term USBR/USGS stations at Carquinez Strait, Mallard Island) – R² > 0.85. Velocity profiles (ADCP data from Golden Gate to Rio Vista). Temperature (seasonal thermal stratification in deep basins).

4. Key Applications 4.1 Water Supply & Salinity Management The model is used daily by the California Department of Water Resources (DWR) to forecast salinity at key export locations (e.g., Clifton Court Forebay). Under low-flow conditions, it informs X2 (distance to 2 psu bottom salinity), a key regulatory metric under the State Water Resources Control Board’s Bay-Delta Water Quality Control Plan. 4.2 Contaminant Transport & TMDLs SFBayModel simulates the fate of mercury, selenium, and PCBs. For example, it has been applied to the South Bay Mercury TMDL (Total Maximum Daily Load) to assess methylation hotspots and fish tissue concentrations. 4.3 Climate Change & Sea-Level Rise By coupling hydrodynamic runs with sea-level rise projections (0.5–2.0 m by 2100), the model predicts:

Increased salinity intrusion, threatening agricultural diversions in the Delta. Loss of intertidal habitat (mudflats, marsh plains) if vertical accretion cannot keep pace. Changes in tidal prism and circulation patterns. San Francisco District, U

4.4 Larval Transport & Endangered Species Particle tracking modules (Lagrangian) are coupled with SFBayModel to simulate the drift of Delta smelt and longfin smelt larvae. These simulations help set allowable export rates under the Biological Opinions for the federal Central Valley Project and State Water Project. 5. Strengths & Limitations 5.1 Strengths

High spatial resolution in complex geometry (islands, sloughs, submerged channels). Unstructured grid flexibility – avoids stair-step artifacts of Cartesian models. Long-term stability – capable of multi-decadal simulations (e.g., 1980–present). Open-source accessibility (UnTRIM versions are freely available for research).