Winnemem Wintu Salmon Restoration Plan for the McCloud River

Winnemem Wintu | February 1st, 2016

The National Marine Fisheries Service 2009 Biological Opinion for salmon specifically calls out for volition passage alternatives to be investigated and considered. [The

The National Marine Fisheries Service 2009 Biological Opinion for salmon specifically calls out for volition passage alternatives to be investigated and considered. [The Winnemem Wintu] have not seen any real evidence that the Pilot Project is even considering this option. Fortunately, the Winnemem Wintu Tribe has a solution to the above, a full repatriation and restoration of the Salmon to the McCloud River, their Spiritual and Cultural home. It is those Spiritual and Cultural ties and beliefs that have sustained us thus far, and will continue to sustain us as we bring our NUR (Salmon) back home. We therefore request that the following Spiritual, Cultural and Practical Fish Restoration Plan be included in the Pilot Project Plan and submitted out for public comment and consideration.

Winter melt trends portend widespread declines in snow water resources

Nature Portfolio (Springer Nature) | April 5th, 2021

In many mountainous regions, winter precipitation accumulates as snow that melts in the spring and summer, which provides water to one billion people globally. Climate wa

In many mountainous regions, winter precipitation accumulates as snow that melts in the spring and summer, which provides water to one billion people globally. Climate warming and earlier snowmelt compromise this natural water storage. Although snowpack trend analyses commonly focus on the snow water equivalent (SWE), we propose that trends in the accumulation season snowmelt serve as a critical indicator of hydrological change. Here we compare long-term changes in the snowmelt and SWE from snow monitoring stations in western North America and find 34% of stations exhibit increasing winter snowmelt trends (P < 0.05), a factor of three larger than the 11% showing SWE declines (P < 0.05). Snowmelt trends are highly sensitive to temperature and an underlying warming signal, whereas SWE trends are more sensitive to precipitation variability. Thus, continental-scale snow water resources are in steeper decline than inferred from SWE trends alone. More winter snowmelt will complicate future water resource planning and management.

Winter wet–dry weather patterns driving atmospheric rivers and Santa Ana winds provide evidence for increasing wildfire hazard in California

Climate Dynamics (Springer) | August 12th, 2022

Floods caused by atmospheric rivers and wildfires fanned by Santa Ana winds are common occurrences in California with devastating societal impacts. In this work

Floods caused by atmospheric rivers and wildfires fanned by Santa Ana winds are common occurrences in California with devastating societal impacts. In this work, we show that winter weather variability in California, including the occurrence of extreme and impactful events, is linked to four atmospheric circulation regimes over the North Pacific Ocean previously named and identified as the “NP4 modes”. These modes come in and out of phase with each other during the season, result- ing in distinct weather patterns that recur throughout the historical record. Some phase combinations favor atmospheric river landfalls and extreme daily or multi-day precipitation, while other phase combinations favor anomalously hot weather and drying Santa Ana wind conditions over Southern California. This historical perspective of atmospheric circulation and impacts over 70 years reveals that weather patterns are changing in a way that enhances wildfire hazard in California, while the frequency of weather patterns linked to historical floods is not diminishing. These changes highlight the rising hazards of cascading weather extremes in California’s present and future.

Working Draft Scientific Basis Report for New and Revised Flow Requirements on the Sacramento River and Tributaries, Eastside Tributaries to the Delta, Delta Outflow, and Interior Delta Operations

California State Water Resources Control Board (SWRCB) | October 14th, 2016

This working draft Scientific Basis Report (Report) is being prepared to support the update of the Bay-Delta Plan’s protection of fish and wildlife beneficial uses in t

This working draft Scientific Basis Report (Report) is being prepared to support the update of the Bay-Delta Plan’s protection of fish and wildlife beneficial uses in the Sacramento River watershed and related areas, known as Phase II.1 This update considers four categories of requirements: (1) new inflow requirements for the Sacramento River, its tributaries, and eastside tributaries to the Delta; (2) changes to Delta outflow requirements; (3) new and modified interior Delta flow requirements; and (4) new requirements for cold water habitat. A comprehensive regulatory approach is needed that protects Bay-Delta fish and wildlife throughout their migratory range, and that better integrates the regulatory framework addressing inflows, outflows, and water project operations. Such a framework will help avoid overreliance on one stream to meet flow and other water quality requirements by providing necessary flows on multiple tributaries to ensure suitable habitat and migratory pathways upstream of the Bay-Delta. Another goal is to employ a strategy that provides for timely action, flexibility, and integration with other planning, science, restoration, and regulatory efforts so action can be taken before imperiled species in the watershed are no longer able to be restored.

Workshop on Delta Outflows and Related Stressors Panel Summary Report

Delta Stewardship Council (Delta Council) | May 15th, 2014

This report was prepared as part of the State Water Resources Control Board’s (“Board”) process of developing and implementing updates to the Bay-Delta Plan and flo

This report was prepared as part of the State Water Resources Control Board’s (“Board”) process of developing and implementing updates to the Bay-Delta Plan and flow objectives to protect beneficial uses in the Bay-Delta Watershed. The focus of this report is Delta outflows and related stressors. The report is based upon reading extensive background materials selected by the Delta Science Program as well as materials identified by individual Panel members to be relevant, a two-day public meeting that included a number of presentations and during which public comments were received by the Panel, review of some of the materials provided during and after the meeting, and the Panel’s internal discussion and deliberations. The Board conducted a review of the current 2006 Bay-Delta Plan in 2009 and determined that Delta outflows and other requirements for the protection of fish and wildlife beneficial uses should be considered for revision. “Delta Outflows and Related Stressors” was further identified by the Delta Science Program as one of four topics emerging from a series of Board workshops in 2012 for which additional workshops should be conducted to provide input on the best available scientific information. Delta outflows and their management have been the subject of extensive scientific and management discussion for decades. A benchmark in this discourse is the report from a series of technical workshops facilitated by Dr. Jerry Schubel (Schubel et al. 1993). Schubel notes in the preface to that report that estuarine standards are required to protect the estuarine ecosystem from “further degradation” until “debate and disagreement over the relative importance of the benefits of low salinity habitat and therefore of flow, on the one hand, and of the liabilities of the physical diversion of a portion of that flow and the associated processes of entrainment of organisms, on the other,” can be resolved with a degree of scientific certainty acceptable to the Board. To some extent, this Panel has been asked to revisit whether standards for Delta outflow are still required, and to identify the degree of scientific certainty regarding the importance of Delta outflow to the ecosystem relative to other stressors.

Workshop on Improving Sub-Seasonal and Seasonal Precipitation Forecasting for Drought Preparedness

California Department of Water Resources (DWR) | October 15th, 2015

Skillful sub-seasonal (monthly) to seasonal (the water year) precipitation forecasting would support many facets of water management, providing lead time for preparing fo

Skillful sub-seasonal (monthly) to seasonal (the water year) precipitation forecasting would support many facets of water management, providing lead time for preparing for extreme events and allowing for more efficient operation of water infrastructure. Current forecast practices and scientific capabilities for making skillful forecasts beyond the weather time domain, however, are limited. Through a series of prior annual workshops on climate variability, climate extremes, and drought held by the Council and the California Department of Water Resources (CDWR), some possible opportunities for improving forecasting skill at a regional scale have been identified. The purpose of this May 2015 workshop was to develop a Western vision for improving monthly and seasonal precipitation forecasting, loosely modeled after the Council’s vision for an observing network for Western extreme precipitation. The analyses performed to understand patterns responsible for heavy precipitation events at a regional scale – such as atmospheric river storms or the Southwest monsoon -- also point out pathways to explore for improving forecasting of these events. The timing is ripe for efforts to improve monthly and seasonal forecasting. Drought in the West has called attention to the need for better information to support preparedness and response, and NOAA’s report on the California drought provides a focal point for followup actions. The National Weather Service (NWS) is reviewing approaches for developing experimental week three and week four outlooks. The National Research Council has convened a committee to develop a U.S. research agenda to advance subseasonal to seasonal forecasting.

Workshop on the Interior Delta Flows And Related Stressors Panel Summary Report

Delta Stewardship Council (Delta Council) | August 6th, 2014

On April 16 and 17, 2014, the Delta Science Program convened an expert Panel (the Panel) and a workshop to identify the best available science to inform the State Water R

On April 16 and 17, 2014, the Delta Science Program convened an expert Panel (the Panel) and a workshop to identify the best available science to inform the State Water Resources Control Board’s (the Board) decisions regarding interior Delta flow requirements to protect beneficial uses of water in the San Francisco Bay/Sacramento-San Joaquin Estuary (Bay-Delta Plan). This workshop and others were convened to provide advice to the Board on issues important to updating the 2006 Bay Delta Plan. At the workshop, the Panel (consisting of the authors of this report) heard presentations from a variety of experts on Delta flows and on species and ecological responses to flow. The Panel was also provided with a selection of scientific reports relevant to the effects of interior Delta flows on fish and their environment in the Delta. This report is informed by both the written and oral information provided to the Panel as well as by other publications that the Panel felt were necessary to satisfy its charge.  The Panel did not make a thorough independent search of the literature on the Sacramento-San Joaquin Delta to determine if there were additional publications that were relevant to its charge. In this report we summarize what is known about the direct and indirect relationships between interior Delta flows and listed fish species. We then use this knowledge to address a set of specific questions posed by the Delta Science Program and the Board.

Workshop report—Earthquakes and High Water as Levee Hazards in the Delta

Delta Stewardship Council (Delta Council) | September 30th, 2016

Earthquakes and high water as hazards to Delta levees were reviewed in a seven-hour workshop organized by the Delta Independent Science Board and held at the campus of th

Earthquakes and high water as hazards to Delta levees were reviewed in a seven-hour workshop organized by the Delta Independent Science Board and held at the campus of the University of California, Davis. Earthquake hazards in the Delta were described in terms of ground motions from Bay Area earthquakes, infrequent earthquake recurrence on faults beneath the Delta, and levee fills prone to earthquake-induced liquefaction. Large uncertainties attend all these seismic elements of levee hazard. Those uncertainties, according to presentations in the workshop, include whether the Delta ground motions previously computed for Bay Area earthquakes were too large.  Hazards from high water were deemed greatest from the confluence of high river discharge, wind-driven surge and waves, and high tides. Major risk assessments have used available data on these hazards without mandates to advance the science. Research needs and opportunities identified in the workshop include expanded observations of Delta ground motions, improved estimates of geologically recent displacement on faults beneath the Delta, further identification of liquefiable materials and mechanisms beneath levees, continued airborne measurements of land-level change, updated mapping of the contracting area of remaining peat, and fuller documentation of past levee failures. Recurring assessments of earthquake hazards and climate change provide precedents for periodic reappraisal of Delta levee risk. The workshop brought together different parts of the diverse community of Delta levee specialists. Positive responses to the workshop suggest that it served levee specialists and outsiders alike.

Workshop report—Earthquakes and High Water as Levee Hazards in the Sacramento-San Joaquin Delta

Delta Stewardship Council (Delta Council) | September 30th, 2016

World’s largest dam removal reverses coastal erosion

Nature Portfolio (Springer Nature) | September 27th, 2019