San Diego Basin Study

U.S. Bureau of Reclamation (USBR) | August 15th, 2017

The purpose of the San Diego Basin Study (Basin Study) is to determine potential climate change impacts on water supplies and demands within the San Diego region and to i

The purpose of the San Diego Basin Study (Basin Study) is to determine potential climate change impacts on water supplies and demands within the San Diego region and to identify how potential adaptation strategies could mitigate supply shortages. The intention of Task 2.3 is to create a computer simulation model to forecast supply and demand imbalances under current and future conditions, and current and future demands under a baseline water system infrastructure in the Study Area. This Interim Report describes the methodologies and findings of this Task. 

San Francisco Bay Shore Inventory: Mapping for Sea Level Rise Planning

San Francisco Estuary Institute (SFEI) | July 1st, 2016

With rising sea levels and the increased likelihood of extreme weather events, it is important for regional agencies and local municipalities in the San Francisco Bay Are

With rising sea levels and the increased likelihood of extreme weather events, it is important for regional agencies and local municipalities in the San Francisco Bay Area to have a clear understanding of the status, composition, condition, and elevation of our current Bay shore, including both natural features and built infrastructure. The purpose of this Bay shore inventory is to create a comprehensive and consistent picture of today’s Bay shore features to inform regional planning. This dataset includes both structures engineered expressly for flood risk management (such as accredited levees) and features that affect flooding at the shore but are not designed or maintained for this purpose (such as berms, road embankments, and marshes). This mapping covers as much of the ‘real world’ influence on flooding and flood routing as possible, including the large number of non-accredited structures. This information is needed to: identify areas vulnerable to flooding. identify adaptation constraints due to present Bay shore alignments; and suggest opportunities where beaches, wetlands, and floodplains can be maintained or restored and integrated into flood risk management strategies. The primary focus of the project is therefore to inform regional planners and managers of Bay shore characteristics and vulnerabilities. The mapping presented here is neither to inform FEMA flood designation nor is it a replacement for site-specific analysis and design. The mapping consists of two main elements: Mapping of Bay shore features (levees, berms, roads, railroads, embankments, etc.) which could affect flooding and flood routing. Attributing Bay shore features with additional information including elevations, armoring, ownership (when known), among others. SFEI delineated and characterized the Bay shore inland to 3 meters (10ft) above mean higher high water (MHHW) to accommodate observed extreme water levels and the commonly used range of future sea level rise (SLR) scenarios. Elevated Bay shore features were mapped and classified as engineered levees, berms, embankments, transportation structures, wetlands, natural shoreline, channel openings, or water control structures. Mapped features were also attributed with elevation (vertical accuracy of <5cm reported in 30 meter (100ft) segments from LiDAR derived digital elevation models (DEMs), FEMA accreditation status, fortification (e.g., riprap, buttressing), frontage (e.g., whether a feature was fronted by a wetland or beach), ownership, and entity responsible for maintenance. Water control structures, ownership, and maintenance attributes were captured where data was available (not complete for entire dataset). The dataset was extensively reviewed and corrected by city, county, and natural resource agency staff in each county around the Bay. This report provides further description of the Bay shore inventory and methods used for developing the dataset. The result is a publicly accessible GIS spatial database.

Santa Ana Canal

Scientific American | March 10th, 1900

THE area discussed in this report is in Southern California, lying for the most part easterly from the city of San Bernardino and consisting of the upper or higher par

THE area discussed in this report is in Southern California, lying for the most part easterly from the city of San Bernardino and consisting of the upper or higher part of the valley in which is situated the town of Redlands. It is a bout 50 miles distant from the ocean and has an elevation of from 1,000 to 1, 500 feet in the vicinity of San Bernardino and Redlands. Northerly and easterly from the valley the mountains rise abruptly, reaching altitudes of fro m 6,000 to 7,000 feet, a few of the peaks rising to 10,000 or even 11,000 feet. The abrupt slopes by which the valley is bounded aid in producing a rainfall relatively heavy for the arid region. The waters, uniting into streams, descend rapidly through narrow gorges, issuing finally upon accumulations of bowlders and smaller debris which stretch in fan-shaped masses away from the mouth of each canyon. The region, though dry, has thus a notable water supply and the exceptional climate and soil have resulted in an extraordinary development of agriculture by irrigation. Lands and crops have reached high values in San Bernardino Valley and expensive irrigation works have been built. A denser population is supported than in any other farming region of the West. This has been accomplished in spite of the fact that the cost of constructing works and of reclaiming the lands has been very great. Additional resources on Lippincott: J.B. Lippincott Papers, University of California, Riverside The Santa Ana River: How it Shaped Orange County

Scaling protection and restoration of natural infrastructure to reduce flood impacts and enhance resilience

Shore & Beach (American Shore and Beach Preservation Association) | January 10th, 2020

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction strat

Restoring natural infrastructure offers much promise as a means to reduce both flood hazard and exposure to complement and supplement other flood damage reduction strategies. Interest increased in flood risk reduction methods using natural and nature-based features, in part, because of increased recognition that such could provide both flood risk reduction and other benefits, such as water quality uplift, community recreational space, and fish and wildlife habitat. Recent flood disasters and the rising costs of disaster response and recovery have triggered policy shifts toward economically efficient investments that enhance greater community resilience. While natural infrastructure is becoming more widely recognized as a tactic for building community and ecological resilience to erosion and flooding, it remains underutilized. Actions to aid consideration of natural infrastructure and scale up its use are presented.

Science be Dammed: How Ignoring Inconvenient Science Drained the Colorado River

University of Arizona Press | November 26th, 2019

Science Be Dammed is an alarming reminder of the high stakes in the management—and perils in the mismanagement—of water in the western United States.  It seems decep

Science Be Dammed is an alarming reminder of the high stakes in the management—and perils in the mismanagement—of water in the western United States.  It seems deceptively simple: even when clear evidence was available that the Colorado River could not sustain ambitious dreaming and planning by decision-makers throughout the twentieth century, river planners and political operatives irresponsibly made the least sustainable and most dangerous long-term decisions. Arguing that the science of the early twentieth century can shed new light on the mistakes at the heart of the over-allocation of the Colorado River, authors Eric Kuhn and John Fleck delve into rarely reported early studies, showing that scientists warned as early as the 1920s that there was not enough water for the farms and cities boosters wanted to build. Contrary to a common myth that the authors of the Colorado River Compact did the best they could with limited information, Kuhn and Fleck show that development boosters selectively chose the information needed to support their dreams, ignoring inconvenient science that suggested a more cautious approach. Today water managers are struggling to come to terms with the mistakes of the past. Focused on both science and policy, Kuhn and Fleck unravel the tangled web that has constructed the current crisis. With key decisions being made now, including negotiations for rules governing how the Colorado River water will be used after 2026, Science Be Dammed offers a clear-eyed path forward by looking back. Understanding how mistakes were made is crucial to understanding our contemporary problems. Science Be Dammed offers important lessons in the age of climate change about the necessity of seeking out the best science to support the decisions we make.

Sea Level Rise Impacts on Wastewater Treatment Systems Along the U.S. Coasts

American Geophysical Union (AGU) | April 13th, 2018

Wastewater treatment plants are susceptible to flooding resulting from sea level rise. Previous estimates of wastewater exposure have only considered the impacts of mar

Wastewater treatment plants are susceptible to flooding resulting from sea level rise. Previous estimates of wastewater exposure have only considered the impacts of marine flooding at the local or regional scale. In this analysis, we quantify the exposure to marine flooding across the coastal United States and then consider the relative impacts of marine and groundwater flooding at the regional scale in the San Francisco Bay Area. We also estimate the number of people who may lose access to wastewater services if no actions are taken to prevent flooding at wastewater treatment plants. We find that the number of people impacted by sea level rise due to loss of wastewater services could be five times as high as previous predictions of the number of people who experience direct flooding of their homes or property. We also find that groundwater flooding poses a significant threat to wastewater plants in the San Francisco Bay region.

Sea Level Rise Vulnerability Study for the City of Los Angeles

University of Southern California Sea Grant Program | December 31st, 2013

Climate change is expected to usher in an era of higher temperatures, increased precipitation and/or severe drought, and increased rates of sea level rise around

Climate change is expected to usher in an era of higher temperatures, increased precipitation and/or severe drought, and increased rates of sea level rise around the world. According to the National Research Council (NRC), global sea level has risen at an increasing rate since the late 19th / early 20th Century, when global temperatures first started to rise. Climate researchers believe sea level rise will drive storm surge and wave run-up higher than current conditions, thereby causing more extensive and frequent coastal, storm-driven flooding. Sea level rise in Los Angeles is expected to match global projections over the next century with anincrease of 0.1 - 0.6 meters (m), or 0.3 - 2.0 feet (ft), from 2000 - 2050 and 0.4 - 1.7 m (or 1.3 - 5.6 ft) from 2000 - 2100 (NRC 2012). Tides, wave-driven run-up, and storm surge play critical roles in coastal flooding in Southern California, especially when big wave storms occur at or near peak high tides. Sea level rise will potentially exacerbate the damage from these events.

Sea Level Variations of the United States 1854–2006

National Oceanic and Atmospheric Administration (NOAA) | December 19th, 2009

The United States National Water Level Network (NWLON) was established in the 19th Century to ensure the Nation’s nautical charts, shoreline maps, and elevations relat

The United States National Water Level Network (NWLON) was established in the 19th Century to ensure the Nation’s nautical charts, shoreline maps, and elevations relative to homes, levees, and other coastal infrastructure were accurately referenced to sea level. In support of this mission, NOAA’s Center for Operational Oceanographic Products and Services and its predecessors have determined sea level for the United States since the mid 19th Century. While climate change was not a concern during the mid-1800s, the accurate determination of sea level was critical for navigation and marine boundary determination. To meet these important requirements, technology, procedures, and processes were developed to the highest scientific and engineering standards. At the turn of the 20th Century it was realized that there was a need to account for a rise in sea level and the first National Tidal Datum Epoch was established. Today this Epoch is updated every 20 to 25 years. The Supreme Court recognized these standards and procedures in the landmark 1936 case of Borax, Ltd v. City of Los Angeles when legally defining sea level. Due to those initial efforts and the continued dedication of those charged with the responsibility for monitoring sea level for the United States, we can accurately determine relative (local) mean sea level along the Nation’s coastline today. These observations also play an important role in monitoring change in global sea level. As we monitor change in sea level into the 21st Century, the statement made by Alexander Dallas Bache, the Second Superintendent of the Coast Survey, is as relevant today as when it was stated more than 150 years ago, “It seems a very simple task to make correct tidal observations; but, in all my experience, I have found no observations which require such constant care and attention” (1854). Michael Szabados, Director, Center for Operational Oceanographic Products and Services

Sharing the Cost: Accelerating Water Resilience through Infrastructure Finance in California

Milken Institute | December 12th, 2022

Sharpening of cold-season storms over the western United States

Nature Portfolio (Springer Nature) | January 19th, 2023

Winter storms are responsible for billion-dollar economic losses in the western United States. Because storm structures are not well resolved by global climate models, it

Winter storms are responsible for billion-dollar economic losses in the western United States. Because storm structures are not well resolved by global climate models, it is not well established how single events and their structures change with warming. Here we use regional storm-resolving simulations to investigate climate change impact on western US winter storms. Under a high-emissions scenario, precipitation volume from the top 20% of winter storms is projected to increase by up to 40% across the region by mid-century. The average increase in precipitation volume (31%) is contributed by 22% from increasing area coverage and 19% from increasing storm intensity, while a robust storm sharpening with larger increase in storm centre precipitation compared with increase in storm area reduces precipitation volume by 10%. Ignoring storm sharpening could result in overestimation of the changes in design storms currently used in infrastructure planning in the region.