State Water Project Seismic Loading Criteria Report

California Department of Water Resources (DWR) | September 19th, 2012

Seismic loading criteria are developed for various types of structures in the State Water Project (SWP) to use in future designs and evaluations. The SWP system supplies

Seismic loading criteria are developed for various types of structures in the State Water Project (SWP) to use in future designs and evaluations. The SWP system supplies water for almost two third of Californians and about 750,000 acres of irrigated farmlands. It is critical for the California economy. Seismic risk is considered one of the greatest contributors of all potential risk categories for the SWP. California is considered one of most seismically vulnerable areas in the world and most of the SWP facilities are located in central and southern California, which are seismically active areas. The purpose of developing seismic loading criteria was to have an economically feasible SWP system that would provide adequate protection against the loss of life, property damage, and interruption of water delivery during and immediately after a seismic event. Most of the existing SWP facilities have not been evaluated since they were built in the 1960s. The knowledge of ground motion predictions and seismic analytical methodologies has significantly progressed since the1960s. As part of the development of the seismic loading criteria, current design standards used by Department of Water Resources (DWR), other similar agencies, and regulatory/code entities were gathered and utilized to select appropriate minimum loading levels for different types of SWP facilities. In addition, the process of criteria selection included consideration of the consequences of failure such as loss of life, property damage, and interruption of water delivery. The consequence of interruption of water delivery was somewhat difficult to quantify because DWR delivers water to the water contractors and they either store it in their storage facilities or distribute to the local agencies. The recommended loading criteria include consideration of consequences of failures in the selection process. The Division of Engineering (DOE) in DWR should use the seismic loading criteria recommended in this report for the design and evaluation of both new and existing SWP facilities. Seismic loading criteria is provided for most of the structures associated with the SWP—reservoirs , dams, canals, pipelines, tunnels, check structures, pumping and power plants, buildings, bridges and utility overcrossings of the aqueduct. The seismic loading criteria should be used for these structures and associated appurtenant facilities in the future. A project engineer can use a larger loading criteria than what is recommended in this report based on project specific factors such as: 1) the consequences of interruption of water delivery, 2) the impact on existing habitats and the environment, 3) the operational aspects of the facility in relation to water delivery, 4) the repair cost and time to return the system back to operational status, and 5) the availability of an emergency back-up system to temporarily make the facility operational until all the repairs are completed. The criteria recommended in this report are considered current; however, these seismic loading criteria should be reviewed and updated every five years to make appropriate changes based on future operational requirements and on changes in state-of-practice. This is the first time DWR has developed loading criteria for the entire SWP facility and many of these facilities have not been evaluated to determine how vulnerable the system would be based on any seismic criteria. Therefore, these criteria are considered preliminary until the recommendations can be confirmed to be reasonable for the SWP facilities.

Status and trends of dam removal research in the United States

Wires Water (Wiley) | September 6th, 2016

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam‐removal studies will increasingly be called upon to inform decisions about whether, and how best, to bring down dams. This raises a critical question: what is the current state of dam‐removal science in the United States? To explore the status, trends, and characteristics of dam‐removal research in the U.S., we searched the scientific literature and extracted basic information from studies on dam removal. Our literature review illustrates that although over 1200 dams have been removed in the U.S., fewer than 10% have been scientifically evaluated, and most of these studies were short in duration (<4 years) and had limited (1–2 years) or no pre‐removal monitoring. The majority of studies focused on hydrologic and geomorphic responses to removal rather than biological and water‐quality responses, and few studies were published on linkages between physical and ecological components. Our review illustrates the need for long‐term, multidisciplinary case studies, with robust study designs, in order to anticipate the effects of dam removal and inform future decision making

Storage Capacity and Sedimentation Characteristics of the San Antonio Reservoir, California, 2018

U.S. Geological Survey (USGS) | January 15th, 2020

Stormwater Capture in California: Innovative Policies and Funding Opportunities

Pacific Institute | June 27th, 2018

Stormwater has traditionally been managed to mitigate flooding and protect water quality. However, its potential as a local water supply has gained recent attention in wa

Stormwater has traditionally been managed to mitigate flooding and protect water quality. However, its potential as a local water supply has gained recent attention in water-stressed areas. As climate change increases the risk of both floods and droughts in California, urban stormwater capture also offers a significant opportunity to enhance community resilience. Moreover, stormwater capture, especially when done with green infrastructure, can improve air quality, provide habitat, and reduce energy use, among other benefits. State agencies have made major efforts to support stormwater capture, from adopting statewide stormwater use goals to clarifying the regulatory framework and dedicating funds for green infrastructure and multi-benefit stormwater projects. This report presents a summary of regulations, laws, and statewide initiatives that create the legal framework for stormwater capture in California. In addition, the report explores examples of successful stormwater programs, initiatives, and funding schemes from communities in California and beyond that directly and indirectly support stormwater capture and use. It concludes with a set of recommendations to overcome obstacles and expand stormwater capture in the state.

Stormwater Capture: Enhancing Recharge and Direct Use Through Data Collection

Southern California Water Coalition | April 26th, 2018

The purpose of this 2018 white paper update is to gain a better understanding of actual stormwater runoff capture volumes, costs, benefits, and project performa

The purpose of this 2018 white paper update is to gain a better understanding of actual stormwater runoff capture volumes, costs, benefits, and project performance across the region to inform future discussions. This white paper augments prior efforts and uses the most recent and best available stormwater project data. Previously in January 2012, the SCWC published its first white paper on stormwater titled Stormwater Capture: Opportunities to Increase Water Supplies in Southern California (SCWC 2012). The purpose of the 2012 white paper was to examine existing statewide policies, goals, and regional plans related to integrated stormwater management; trends, structure, and requirements of MS4 permits as they pertain to both opportunities and constraints to maximizing stormwater capture for water supply purposes; and the advantages and disadvantages of two strategies of stormwater management: onsite low impact development and regional stormwater capture and infiltration. Lastly, the 2012 white paper largely focused on conceptual stormwater projects and technical strategies for increasing stormwater capture. Since the 2012 white paper, many of the proposed projects were constructed and in operation. Other plans such as Metropolitan’s 2015 Integrated Resources Plan (MWD 2016), the City of Los Angeles’s Stormwater Capture Master Plan (LADWP 2015), and Los Angeles County Flood Control District’s LA Basin Study (LACFCD 2016) also estimated stormwater capture and costs. The SCWC saw an opportunity to evaluate the costs and benefits of these constructed stormwater capture projects and pursued a white paper update.

Summary of Climate Change Impacts to Water and Sanitation for Frontline Communities in the United States: Water, Sanitation, and Climate Change in the United States Part 1

Pacific Institute | December 6th, 2023

Climate change is among the most urgent, wide-ranging crises we face. It poses significant challenges and is already resulting in severe impacts to drinking water and san

Climate change is among the most urgent, wide-ranging crises we face. It poses significant challenges and is already resulting in severe impacts to drinking water and sanitation access—both for those currently living without access and for communities where forces like drought, flooding, sea-level rise, wildfires, and intensifying storms threaten to degrade or strip basic services from the people. Access to sufficient, safe, acceptable, physically accessible, and affordable water and sanitation is essential for human health and wellbeing, as well as economic prosperity—and climate change will inevitably make ensuring all have access more challenging. Without water and sanitation access, people do not have water to drink, cannot clean, shower, or wash their hands, and cannot safely dispose of human waste. They may have to travel long distances to purchase and haul water back to their homes. Without access to water, they also have less ability to cool their homes, protect themselves from wildfires, and work or go to school. An economic assessment by DigDeep found that for every household in the United States without access to water and sanitation, the domestic economy loses $15,800 annually in extra health care costs, time and money spent on bottled water, lost educational or work opportunities, and premature death (DigDeep 2022). (Click here for Part 2)

Summary of Draft Environmental Impact Report Peripheral Canal Project

California Department of Water Resources (DWR) | August 1st, 1974

Support for Sediment Bioaccumulation Evaluation: Toxicity Reference Values for San Francisco Bay

San Francisco Estuary Institute (SFEI) | December 3rd, 2018

This special study of the Regional Monitoring Program for Water Quality in San Francisco Bay was conducted to support the Dredged Material Management Office (DMMO) proces

This special study of the Regional Monitoring Program for Water Quality in San Francisco Bay was conducted to support the Dredged Material Management Office (DMMO) process of evaluating results from bioaccumulation testing performed for routine dredging projects. The goal was to use the current DMMO methodology for selecting Toxicity Reference Values (TRVs) from the US Army Corps of Engineers Environmental Residue-Effects Database (ERED), in order to develop a standard list of TRVs for San Francisco Bay. TRVs are used as a conservative screening tool to efficiently evaluate whether observed invertebrate test organism body burdens could indicate adverse ecological effects on benthic organisms in situ. Currently, there are no published standard TRVs for the Bay, and TRV selection is presently performed on a case-by-case basis during the evaluation of bioaccumulation testing results submitted by individual dredgers. A standard list would promote consistent application of the methodology and improve the efficiency of dredging project evaluations. 

Sustainable Landscapes on Commercial and Industrial Properties in the Santa Ana River Watershed

Pacific Institute | February 14th, 2019

Pressures on water resources are intensifying due to aging infrastructure, population growth, climate change, and other factors. Marked by vast expanses of thirs

Pressures on water resources are intensifying due to aging infrastructure, population growth, climate change, and other factors. Marked by vast expanses of thirsty lawns and impermeable pavement, California’s urban and suburban communities are ill-equipped to handle these pressures. Outdoor use represents about half of all water used in urbanized areas, and even more in the hottest, driest parts of the state.1,2 Runoff from lawns carries fertilizers and pesticides into waterways. Similarly, impermeable pavement impedes groundwater recharge; contributes to higher peak flows; warms the urban environment; and carries oils, metals, and other toxins into rivers, estuaries, and the ocean. The good news is that there are more sustainable options for California communities. Replacing lawns with climate-appropriate plants that are irrigated efficiently can save water and reduce vulnerability to drought. When integrated with bioswales, rain gardens, and other green infrastructure, these projects can boost local water supplies, reduce flooding, and improve water quality. These practices can also save energy, provide habitat, sequester carbon, improve air quality, boost property values, enhance community livability, and increase resilience to climate change.

Sycamore Alluvial Woodland Planting Guide

San Francisco Estuary Institute (SFEI) | August 1st, 2018

This memo builds on recent field-based studies which examined the relative distribution, health, and regeneration patterns of two major stands of sycamore alluvial woodla

This memo builds on recent field-based studies which examined the relative distribution, health, and regeneration patterns of two major stands of sycamore alluvial woodland (SAW) in Santa Clara County. Given that the acquisition, restoration, and improved management of SAW is mandated as part of the Santa Clara Valley Habitat Plan (VHP), it is increasingly critical to understand how, when, and where sycamores establish, which is critical for successful restoration design and planting success. This memo is meant to summarize recent studies on habitat requirements of the SAW habitat type, and present a planting plan and monitoring framework for restoring SAW habitat at two sites in Santa Clara County. As the science and restoration of SAW is an ongoing topic of interest, we also suggest possible subsequent studies needed to further sycamore restoration goals.