Estuary-Wide Data Repository for the Delta Environmental Data to Understand a California Estuary

San Francisco Estuary Institute (SFEI) | July 1st, 2017

The Sacramento-San Joaquin Delta (Delta) is the backdrop for some of the most pressing water supply and natural resource management issues facing California. To navigate

The Sacramento-San Joaquin Delta (Delta) is the backdrop for some of the most pressing water supply and natural resource management issues facing California. To navigate such matters comprehensively with transparency, and rigor, it is important to ensure broad dissemination of data. An Environmental Data Summit held in 2014 created a new era in information management and knowledge discoveries, and shed light on challenges associated with the use of disparate datasets. The Delta Environmental Data for the Understanding a California Estuary (DEDUCE), a collaborative project, builds upon the Data Summit vision and initiated a forum to integrate disparate data from multiple sources and legacy data that are currently not in any of the State’s data sharing systems. DEDUCE expanded the existing infrastructure to house water quality data from the Delta to address management questions by identifying and collecting high priority data according to rigorous business rules and mapping these data to a central system. This important step of harmonizing the data improves its interoperability and increases the access to and exchange of high-quality environmental data. DEDUCE facilitates the upload, aggregation and display of data in tools such as those created under the auspices of the California Water Quality Monitoring Council, including EcoAtlas and My Water Quality Portals, and CD3: Contaminant Data Display and Download tool for accessing and visualizing data comparable to State standards. DEDUCE achieved collecting and uploading the legacy and toxic contaminant data, and established design standards to exchange future datasets from the initial data storage or database to California Environmental Data Exchange Network (CEDEN). This data integration effort created accurate, accessible, and synthesized data for scientists and decision-makers as a foundation to inform management actions with the best available science.

Exit here: Strategies for dealing with aging dams and reservoirs

Aquatic Sciences (Springer) | October 22nd, 2019

Aging infrastructure is prevalent throughout the world, but water control management structures, specifically dams, are of growing concern. Dams and their corresponding r

Aging infrastructure is prevalent throughout the world, but water control management structures, specifically dams, are of growing concern. Dams and their corresponding reservoirs have inherent, but separate, lifespans. The proportion of dams around the world that continue operation beyond their intended lifespans is growing at an alarming rate. Society will not only have to navigate the tradeoffs associated with the deterioration of services provided by reservoirs and dams, but also impending structural failures. Society is nearing a critical pinch point where we will have to decide how to deal with dams and reservoirs at scales that range from a single system to multiple systems in large watersheds. No comprehensive strategy exists to inform both the range of actions that can be applied to such infrastructure and how such actions would influence biophysical, socioeconomic, and geopolitical tradeoffs. The development of proactive exit strategies is a critical first step in ensuring controlled transitions for aging dams and reservoirs. Herein, we present an overview of actions and considerations for aging dams and reservoirs, followed by an initial framework for exit strategy development to launch a further discussion on how society could deal with this aging infrastructure.

Exploring scientific and management implications of upper trophic level food webs in the Delta

Delta Stewardship Council (Delta Council) | April 17th, 2024

The Sacramento-San Joaquin Delta (the Delta) has complex and evolving ecosystems characterized by multiple food webs that vary in time and space. Here, food webs are defi

The Sacramento-San Joaquin Delta (the Delta) has complex and evolving ecosystems characterized by multiple food webs that vary in time and space. Here, food webs are defined as the network of species interactions (competition, predation) and interactions with their environment that are related through the flow of energy through the ecosystem (e.g., Paine 1980). Physical modifications, in addition to the introduction of non-native species and the changing climate, have significantly altered the structure and energetic pathways of the food webs for decades. The science clearly suggests that predicting the impacts of habitat restoration, fisheries, changes in environmental drivers (e.g., climate, changes in nutrient loading, invasive species) on the ecological carrying capacity and productivity of the Delta, as well as the bioaccumulation of contaminants on species or the ecosystem, requires an understanding of food web processes.

Fish-Habitat Relationships Along the Estuarine Gradient of the Sacramento-San Joaquin Delta, California: Implications for Habitat Restoration

Estuaries and Coasts (Springer) | June 6th, 2018

Estuaries are highly variable environments where fish are subjected to a diverse suite of habitat features (e.g., water quality gradients, physical structure) that filt

Estuaries are highly variable environments where fish are subjected to a diverse suite of habitat features (e.g., water quality gradients, physical structure) that filter local assemblages from a broader, regional species pool. Tidal, climatological, and oceanographic phenomena drive water quality gradients and, ultimately, expose individuals to other habitat features (e.g., stationary physical or biological elements, such as bathymetry or vegetation). Relationships between fish abundances, water quality gradients, and other habitat features in the Sacramento-San Joaquin Delta were examined as a case example to learn how habitat features serve as filters to structure local assemblages in large river-dominated estuaries. Fish communities were sampled in four tidal lakes along the estuarine gradient during summer-fall 2010 and 2011 and relationships with habitat features explored using ordination and generalized linear mixed models (GLMMs). Based on ordination results, landscape-level gradients in salinity, turbidity, and elevation were associated with distinct fish assemblages among tidal lakes. Native fishes were associated with increased salinity and turbidity, and decreased elevation. Within tidal lakes, GLMM results demonstrated that submersed aquatic vegetation density was the dominant driver of individual fish species densities. Both native and non-native species were associated with submersed aquatic vegetation, although native and non-native fish populations only minimally overlapped. These results help to provide a framework for predicting fish species assemblages in novel or changing habitats as they indicate that species assemblages are driven by a combination of location within the estuarine gradient and site-specific habitat features.

Flows and Fishes in the Sacramento-San Joaquin Delta Research Needs in Support of Adaptive Management

Delta Stewardship Council (Delta Council) | August 15th, 2015

Fracturing dams, fractured data: Empirical trends and characteristics of existing and removed dams in the United States

River Research and Applications (Wiley) | May 20th, 2018

Dam removals in the United States continue to accelerate in pace and scope, but no national analyses have examined how removed dams compare with existing dam stock. Here,

Dam removals in the United States continue to accelerate in pace and scope, but no national analyses have examined how removed dams compare with existing dam stock. Here, we review and analyse the best available national data on dams from the National Inventory of Dams (NID), dam removals from American Rivers, the U.S. Geological Survey, and the National River Restoration Science Synthesis databases to compare trends and characteristics of removed versus existing dams in the United States. If historical trends continue, by 2050 the United States can expect between 4,000 and 36,000 total removals, including 2,000–10,000 removals of NID dams. Best‐fit regression models estimate total costs between $50.5 million and $25.1 billion (mean $10.5 billion, median $416.5 million) for all removals and $29.6 million to $18.9 billion (mean $7.2 billion, median $285 million) for NID removals, a significant cost savings over present stated dam rehabilitation needs. Structural characteristics and ages of documented removals are not representative of existing dams, with privately owned hydroelectric dams subject to public oversight and water supply dams the most disproportionately removed. We conclude that dam removal science would benefit from the creation of an interdisciplinary framework for studying dams as environmental, social, and technological interventions, facilitated by transparent datasets around dams and removals and reflexive research approaches that combine statistical approaches with place‐based analyses.

Gage Gap

Nature Conservancy | October 31st, 2018

Following a difficult five-year drought, California just had one of the wettest winters on record. The state is famous for its highly engineered water system, whi

Following a difficult five-year drought, California just had one of the wettest winters on record. The state is famous for its highly engineered water system, which moves millions of gallons of water from north to south and east to west. Thirty-nine million people and our $47 billion agricultural industry rely on that water, not to mention wildlife from the Sierra to the sea. And yet we have surprisingly little data about how much water is moving through our streams at any given time. There are over 3,600 locations in California where stream gages have been active at some point, but only 54% have been active recently. And even fewer of those provide the kind of rich, real-time reporting needed to manage what is arguably our state’s most precious and contentious resource.

Gaps and opportunities in nitrogen pollution policies around the world

Nature Portfolio (Springer Nature) | July 6th, 2020

Nitrogen pollution is an important environmental issue gaining traction in policy circles. However, there is little understanding of current nitrogen policies around the

Nitrogen pollution is an important environmental issue gaining traction in policy circles. However, there is little understanding of current nitrogen policies around the world: whether they account for nitrogen’s unique ability to exacerbate multiple environmental impacts or balance nitrogen’s dual role as an essential agricultural input and major pollutant. Here we assemble and analyse the first database of nitrogen policies generated by national and regional legislatures and government agencies, a collection of 2,726 policies across 186 countries derived from the ECOLEX database. The database covers all major environmental sinks (such as air, water and climate), economic sectors (including agriculture, wastewater and industry) and policy instruments (from market mechanisms to regulatory standards). We find that sink-centred policies are focused predominantly on water, mirroring the distribution of nitrogen’s global environmental and human health costs. However, policy integration across sinks is severely lacking, which heightens the risk of substituting one form of nitrogen pollution for another. Moreover, two-thirds of agricultural policies (ranging from broad sectoral programmes to nitrogen-specific measures) incentivize nitrogen use or manage its commerce, demonstrating the primacy of food production over environmental concerns.

Gauging climate preparedness to inform adaptation needs: local level adaptation in drinking water quality in CA, USA

Climatic Change (Springer) | December 23rd, 2013

Understanding resource managers’ perceptions of climate change, analytic capacity, and current adaptation activities can provide insight into what can help support ada

Understanding resource managers’ perceptions of climate change, analytic capacity, and current adaptation activities can provide insight into what can help support adaptation processes at the local level. In California, where a major drought currently demonstrates some of the hardships that could be regularly encountered under a changing climate, we present results from a survey of drinking water utilities about the perceived threat, analytic capacity, and adaptation actions related to maintaining water quality in the face of climate change. Among surveyed utilities (n = 259), awareness is high in regard to climate change occurring and its potential impacts on water quality globally, but perceived risk is lower with regard to climate impacts on local drinking water quality. Just over half of surveyed utilities report at least some adaptation activity to date. The top three variables that most strongly correlated with reported adaptation action were (1) perceived risk on global and local water quality, (2) surface water reliance, and (3) provision of other services beyond drinking water. Other tested variables significantly correlated with reported adaptation action were (4) degree of impact from the current drought and (5) communication with climate change experts. Findings highlight that smaller groundwater-reliant utilities may need the most assistance to initiate climate adaptation processes. Trusted information sources most frequently used across respondents were state government agencies, followed by colleagues in the same utilities. The finding that frequently used sources of information are similar across utilities presents a promising opportunity for training and disseminating climate information to assist those systems needing the most support.

Grand Challenges to Delta Science: Planning for Science in a Dynamic System (Draft)

Delta Stewardship Council (Delta Council) | May 23rd, 2024

The Delta Science Program is in the process of updating the Delta Science Plan for the third iteration. The Delta Science Plan is a collaboratively developed plan, stipul

The Delta Science Program is in the process of updating the Delta Science Plan for the third iteration. The Delta Science Plan is a collaboratively developed plan, stipulated in the Delta Plan, that aims to provide the vision, principles, and approaches for coordinating Delta science actors and communicating the outcomes of science activities and their management implications to decision-makers.