CASCaDE: Computational Assessments of Scenarios of Change for the Delta Ecosystem Active
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.
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
- The hydrodynamic model can be accessed at www.d3d-baydelta.org.
- San Francisco Bay-Delta bathymetric/topographic digital elevation model (DEM)
- Data and Associated Code for Projections of Unimpaired Flows, Storage, and Managed Flows for Climate Change Scenarios in the San Francisco Bay-Delta Watershed, California
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:
Below are data or web applications associated with this project.
Below are publications associated with this project.
Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply
Effects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations
Why are diverse relationships observed between phytoplankton biomass and transport time?
Ingredients in sustainably managing water in semi-arid environments
Hindcasting of decadal‐timescale estuarine bathymetric change with a tidal‐timescale model
Potential Inundation due to Rising Sea Levels in the San Francisco Bay Region
Calibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Principal hydrologic responses to climatic and geologic variability in the Sierra Nevada, California
Temporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations
Modeling soil moisture processes and recharge under a melting snowpack
Climate and floods still govern California levee breaks
- Overview
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.
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
- The hydrodynamic model can be accessed at www.d3d-baydelta.org.
- San Francisco Bay-Delta bathymetric/topographic digital elevation model (DEM)
- Data and Associated Code for Projections of Unimpaired Flows, Storage, and Managed Flows for Climate Change Scenarios in the San Francisco Bay-Delta Watershed, California
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:
- Data
Below are data or web applications associated with this project.
- Publications
Below are publications associated with this project.
Filter Total Items: 47Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply
Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological hydrograph conAuthorsN. K. Ganju, D. H. SchoellhamerEffects of hydrologic infrastructure on flow regimes of California's Central Valley rivers: Implications for fish populations
Alteration of natural flow regimes is generally acknowledged to have negative effects on native biota; however, methods for defining ecologically appropriate flow regimes in managed river systems are only beginning to be developed. Understanding how past and present water management has affected rivers is an important part of developing such tools. In this paper, we evaluate how existing hydrologiAuthorsLarry R. Brown, Marissa L. BauerWhy are diverse relationships observed between phytoplankton biomass and transport time?
Transport time scales such as flushing time and residence time are often used to explain variability in phytoplankton biomass. In many cases, empirical data are consistent with a positive phytoplankton‐transport time relationship (i.e., phytoplankton biomass increases as transport time increases). However, negative relationships, varying relationships, or no significant relationship may also be obAuthorsLisa V. Lucas, Janet K. Thompson, Larry R. BrownIngredients in sustainably managing water in semi-arid environments
The lessons learned from CALFED indicate that ingredients important in the long-term resolution of water management issues may not result in short-term “solutions”. The value of this special issue lies in its identification of ingredients that stimulate re-framing of issues, adapting to new knowledge and innovative decisions. But sustainable water management also requires the political patience toAuthorsSamuel N. LuomaHindcasting of decadal‐timescale estuarine bathymetric change with a tidal‐timescale model
Hindcasting decadal-timescale bathymetric change in estuaries is prone to error due to limited data for initial conditions, boundary forcing, and calibration; computational limitations further hinder efforts. We developed and calibrated a tidal-timescale model to bathymetric change in Suisun Bay, California, over the 1867–1887 period. A general, multiple-timescale calibration ensured robustness ovAuthorsNeil K. Ganju, David H. Schoellhamer, Bruce E. JaffePotential Inundation due to Rising Sea Levels in the San Francisco Bay Region
An increase in the rate of sea level rise is one of the primary impacts of projected global climate change. To assess potential inundation associated with a continued acceleration of sea level rise, the highest resolution elevation data available were assembled from various sources and mosaicked to cover the land surfaces of the San Francisco Bay region. Next, to quantify high water levels throughAuthorsNoah KnowlesCalibration of an estuarine sediment transport model to sediment fluxes as an intermediate step for simulation of geomorphic evolution
Modeling geomorphic evolution in estuaries is necessary to model the fate of legacy contaminants in the bed sediment and the effect of climate change, watershed alterations, sea level rise, construction projects, and restoration efforts. Coupled hydrodynamic and sediment transport models used for this purpose typically are calibrated to water level, currents, and/or suspended-sediment concentratioAuthorsN. K. Ganju, D. H. SchoellhamerPrincipal hydrologic responses to climatic and geologic variability in the Sierra Nevada, California
Sierra Nevada snowpack is a critical water source for California’s growing population and agricultural industry. However, because mountain winters and springs are warming, on average, precipitation as snowfall relative to rain is decreasing, and snowmelt is earlier. The changes are stronger at mid-elevations than at higher elevations. The result is that the water supply provided by snowpack is dimAuthorsDavid H. Peterson, Iris Stewart, Fred MurphyTemporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations
In this study we used hydrologic proxies to develop a daily sediment load time-series, which agrees with decadal sediment load estimates, when integrated. Hindcast simulations of bathymetric change in estuaries require daily sediment loads from major tributary rivers, to capture the episodic delivery of sediment during multi-day freshwater flow pulses. Two independent decadal sediment load estimatAuthorsN. K. Ganju, N. Knowles, D. H. SchoellhamerModeling soil moisture processes and recharge under a melting snowpack
Recharge into granitic bedrock under a melting snowpack is being investigated as part of a study designed to understand hydrologic processes involving snow at Yosemite National Park in the Sierra Nevada Mountains of California. Snowpack measurements, accompanied by water content and matric potential measurements of the soil under the snowpack, allowed for estimates of infiltration into the soil duAuthorsA. L. Flint, L. E. Flint, M. D. DettingerClimate and floods still govern California levee breaks
Even in heavily engineered river systems, climate still governs flood variability and thus still drives many levee breaks and geomorphic changes. We assemble a 155-year record of levee breaks for a major California river system to find that breaks occurred in 25% of years during the 20th Century. A relation between levee breaks and river discharge is present that sets a discharge threshold above wAuthorsJ.L. Florsheim, M. D. Dettinger