San Francisco Bay and Sacramento-San Joaquin Delta DEM for Modeling, Version 4.3

# Citation and Main Description:

This product is described in Chapter 5 of the 2018 DWR Delta Modeling Section annual report, produced jointly with USGS.
https://data.cnra.ca.gov/dataset/methodology-for-flow-and-salinity-estimates-in-the-sacramento-san-joaquin-delta-and-suisun-marsh/resource/84d4fd29-c839-4efa-82be-b58f7ed176db

as well as in ESA. Delta Bathymetry Digital Elevation Model Update Project: Technical Report. California Department of Water Resources, 2024 (Draft) 
Available upon request 

# Domain and Product
This product is a mutually compatible suite of DEMs covering most of the aquatic and terrestrial areas of the Bay-Delta. The product was derived from original point data collections, lidar and other DEMs. Also included in the resources are images and shapefiles describing the source data.

Changes between 4.2 and 4.3 are documented in the change log below. Changes before that are recorded on the 4.2 web page.

Changes in version 4 relative to prior products are limited to the region east of the Carquinez Strait (starting around Carquinez Bridge). To facilitate compatibility between products released by DWR and USGS/NOAA partners, DWR distributes the region west of the active work at 10m resolution but does not actively work in this region. The San Pablo Bay boundary of active revision in the present product in a place where its source data matches that of other Bay elevation models, e.g., the 2m seamless high-resolution bathymetric and topographic DEM of San Francisco Bay by USGS Earth Resources Observation and Science Center (EROS) (https://topotools.cr.usgs.gov/coned/sanfrancisco.php ), the 2010 San Francisco Bay DEM by National Oceanic and Atmospheric Administration (https://www.ngdc.noaa.gov/metaview/page?xml=NOAA/NESDIS/NGDC/MGG/DEM/iso/xml/741.xml&view=getDataView&header=none ) or the prior (version 3) 10m digital elevation model (https://data.cnra.ca.gov/dataset/san-francisco-bay-and-sacramento-san-joaquin-delta-dem-v3 ).The 10m DEM for the Bay-Delta is based on the first on the list, i.e. EROS’ 2m DEM for the Bay

# Version: 4.3
* Time Completed: March 2025
* Horizontal Datum: NAD83
* Spheroid:GRS1980
* Projection:UTM_Zone_10N (meters)
* Vertical Datum:NAVD88 (meters)

# Changes since 4.2
* Develop 2m DEM for the entirety of the South Delta based on new bathymetric surveys collected between 2021-2022 (DWR, NCRO and Cinquini & Passarino Inc) and 2017 Lidar (DWR)
* Develop 2m DEM of the entirety of the South Delta, including all available terrestrial data that covers the islands into a seamless tile
* Develop 2m DEM of Woodward Cut based on the 2017 Bathymetry Survey (DWR, NCRO) and 2017 LiDAR (DWR) 
* Develop 2m DEM of Railroad Cut based on the 2017 Bathymetry Survey (DWR, NCRO) and 2017 LiDAR (DWR) 
* Minor modification to existing dem_montezuma_sl_2m_20200909.tif : fix alignment problem.
* clip dem_ccfb_south_delta_san_joaquin_rvr_2m_20200625.tif to remove areas that are superseded by the dem_south_delta_2m_20231103.tif. Now called dem_omr_sjr_2m_20200625.tif



Tags: Bathymetry, DEM, Delta, Modeling, San Francisco Bay, San Francisco Bay-Delta, Suisun, bay delta
Organization: California Department of Water Resources