CASCaDE: Computational Assessments of Scenarios of Change for the Delta Ecosystem

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The Delta of the Sacramento and San Joaquin rivers provides drinking water supplies to two-thirds of Californians, and is a fragile ecosystem home to threatened and endangered species. The CASCaDE project builds on several decades of USGS science to address the goals of achieving water supply reliability and restoring the ecosystems in the Bay-Delta system.

CASCaDE2 flowchart showing the system of linked models being used to evaluate scenarios of climate and infrastructure change.

CASCaDE2 modeling flowchart showing the system of linked models being used to evaluate scenarios of climate and infrastructure change. The light blue background indicates a framework of mutually compatible models developed by Deltares and USGS and applied by CASCaDE2 team members to the Bay-Delta.

The Delta of the Sacramento and San Joaquin rivers, at the upstream end of the San Francisco Bay-Delta estuary, is home to vital ecosystems that provide habitat for many endangered species and that serve as an important stop on the Pacific Flyway for migratory birds. The Delta provides drinking water supplies to two-thirds of Californians and is a major source of water for California agriculture. 

The health of the estuary’s ecosystem has long been in decline. Continued subsidence of Delta islands, in conjunction with sea-level rise and the likelihood of major earthquakes, threatens hundreds of miles of fragile levees. As a result, the Delta’s ecosystem and the role of its waterways as a central conduit for large-scale infrastructure that transports fresh water from northern California to southern California are vulnerable. Failure of the Delta to sustain its ecological and freshwater supply services would be catastrophic for California, with economic impacts extending to the national level.

In response to these challenges, California passed the Sacramento-San Joaquin Delta Reform Act in 2009 with the coequal goals of achieving water supply reliability and restoring the Delta’s ecosystem. However, critical gaps in our understanding of how the Delta may respond to major climate and infrastructure changes over the next several decades complicate decisions about how to achieve these goals. Assessing the effects of likely climate and infrastructure changes on this system is essential to making informed and robust planning decisions.

The Computational Assessments of Scenarios of Change for the Delta Ecosystem (CASCaDE) project was conceived to build on several decades of USGS science in this system to address this need. Multiple scientists are using linked models to evaluate the implications of a range of future scenarios on various aspects of the Bay-Delta and its watershed.

 

Code, Configuration Files, and Additional Data

 

Updates

August 27, 2020: A paper describing the results of CASCaDE 2 modeling of the response of suspended sediment transport in the Sacramento watershed was published in (link).

October 12, 2018: A paper describing the results of CASCaDE 2 watershed hydrology and operations modeling was published in Water Resources Research (link). We also recently published a related report describing our methods and models in detail, and a data-and-code release that includes all of the code we developed for this project and the relevant data produced.

August 27, 2018: A report describing the meteorological and sea-level projections used in CASCaDE2 has been released as part of the Fourth California Climate Change Assessment (link).

July 1, 2018: Configuration files for the 2-D and 3-D versions of the D-Flow FM hydrodynamic model are available at d3d-baydelta.org. Instructions for obtaining the source code are also at that site.

October 1, 2017: A paper describing the application of the CASCaDE2 hydrodynamical model to the simulation of historical water temperatures has been published in Water Resources Research (link).

June 22, 2017: A report describing the seamless bathymetric/topographic DEM developed for the CASCaDE2 hydrodynamical model has been released (link).

June 5, 2017: A paper describing the new CASCaDE2 hydrodynamical model and its application to historical flows and salinity has been published in Estuarine, Coastal, and Shelf Science (link).

April 2017: A publication exploring responses of estuarine suspended sediment dynamics to scenarios of changing climate and alterations to engineered water conveyance structures (link to Achete et al. 2017 Climatic Change; https://link.springer.com/article/10.1007/s10584-017-1954-8)

February 2017: A publication describing a laboratory analysis method enabling Selenium sample analysis supporting CASCaDE modeling work (link to Kleckner et al. 2017, L&O Methods; https://aslopubs.onlinelibrary.wiley.com/doi/full/10.1002/lom3.10164)

May 14, 2016: A paper describing the watershed sediment model developed for CASCaDE2 has been published in Water (link).

March 2016:  A publication describing suspended sediment dynamics in a tidal channel network under peak river flow based on a 2D numerical model (link to Achete et al. 2016 Ocean Dynamics; https://link.springer.com/article/10.1007/s10236-016-0944-0)

 

Older items

At the conclusion of external funding from the Delta Stewardship Council (DSC), we produced a summary report. Although the project term with DSC funding is over, work continues on CASCaDE2. Additional materials follow: