Climate Change and the Delta

University of California, Davis (UC Davis) | October 1st, 2016

Climate change amounts to a fast approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic

Climate change amounts to a fast approaching, “new” stressor in the Sacramento–San Joaquin Delta system. In response to California’s extreme natural hydroclimatic variability, complex water-management systems have been developed, even as the Delta’s natural ecosystems have been largely devastated. Climate change is projected to challenge these management and ecological systems in different ways that are characterized by different levels of uncertainty. Future precipitation changes are less certain, with as many climate models projecting wetter conditions as drier. Warmer temperatures will likely enhance evaporation and raise water temperatures. Consequently, climate change is projected to yield both more extreme flood risks and greater drought risks. Effects on the Delta ecosystem that are traceable to warming include sea level rise, reduced snowpack, earlier snowmelt and larger storm-driven streamflow, warmer and longer summers, warmer summer water temperatures, and water-quality changes. These changes and their uncertainties will challenge the operations of water projects and uses throughout the Delta’s watershed and delivery areas. Although the effects of climate change on Delta ecosystems may be profound, the end results are difficult to predict, except that native species will fare worse than invaders. Successful preparation for the coming changes will require greater integration of monitoring, modeling, and decision-making across time, variables, and space than has been historically normal.

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Death Valley

Scientific American | August 22nd, 1903

Judging from the many high sensation stories and frequent references to Death Valley, there is evidently a popular interest in that dreaded locality, which is in part e

Judging from the many high sensation stories and frequent references to Death Valley, there is evidently a popular interest in that dreaded locality, which is in part explicable by the name it bears. The stories published are, as a rule, of little value, and give no idea of the climate, topography, fauna, and flora of a more absolute and arid desert than the Sahara. Our great deserts of the southwest have been but little written about by geographers and travelers, and it is only recently that accurate official reports upon them have been made. Capt. Clarence E . Dutton, in his report on the Grand Canon, gave a description of the deserts of northern Arizona. Captain Gaillard, of the Mexican Boundary Commission, has given us, in a popular magazine, probably the best article that has as yet been written on an American desert. He was well qualified to write, because he traversed the entire region from the Rio Grande to the Pacific, erecting monument s to mark the boundary between Mexico and the United States. Mr. W.J. McGee, Chief of the Bureau of American Ethnology, who recently made the journey through Southern Arizona and Mexico, to study the Seri Indians, who live on the Isle of Tiburon in the Gulf of California, has given us a fine description of the desert in his report and in separate articles in the Journal of Geography. A valuable article on the American Desert, by Robert T. Hill, has just appeared.

Delta Overview

California Department of Water Resources (DWR) | March 27th, 2007

The Delta of the Sacramento and San Joaquin Rivers is California’s water supply crossroads. It is the major collection point for water that serves more than 25 million

The Delta of the Sacramento and San Joaquin Rivers is California’s water supply crossroads. It is the major collection point for water that serves more than 25 million people, two-thirds of our State’s population. The maze of islands and channels at the confluence of these two large rivers has long been the focal point of debate surrounding a number of complicated water-related issues of statewide importance. Agricultural, urban, industrial, environmental, and recreational interests have a vital stake in the Delta and a need to understand the physical Delta and its complex interrelationships. This Overview describes the waterways, highways, levees, historic flooding, water supply systems and political boundaries of the Delta to convey a basic understanding of the complexity of the Delta and its significance to the people of California.

Delta Subsidence in California: The sinking heart of the state

U.S. Geological Survey (USGS) | April 8th, 2000

The Sacramento-San Joaquin River Delta of California once was a great tidal freshwater marsh blanketed by peat and peaty alluvium. Beginning in the late 1800s, levees wer

The Sacramento-San Joaquin River Delta of California once was a great tidal freshwater marsh blanketed by peat and peaty alluvium. Beginning in the late 1800s, levees were built along the stream channels, and the land thus protected from flooding was drained, cleared, and planted. Although the Delta is now an exceptionally rich agricultural area (over a $500 million crop value in 1993), its unique value is as a source of freshwater for the rest of the State. It is the heart of a massive north-to-south water delivery system. Much of this water is pumped southward for use in the San Joaquin Valley and elsewhere in central and southern California. The leveed tracts and islands help to protect water-export facilities in the southern Delta from saltwater intrusion by displacing water and maintaining favorable freshwater gradients. However, ongoing subsidence behind the levees reduces levee stability and, thus, threatens to degrade water quality in the massive north-to-south water-transfer system.

Local Water Governance in the Delta

California State Water Resources Control Board (SWRCB) | April 8th, 2014

As the Sacramento San Joaquin Delta (Delta) evolved from an historic tidally-influenced marshland to a diverse agricultural region, local water governance structures also

As the Sacramento San Joaquin Delta (Delta) evolved from an historic tidally-influenced marshland to a diverse agricultural region, local water governance structures also evolved to meet the water needs of the area. The purpose of this report is to outline the development of these local water governance structures.

River Meandering

American Geophysical Union (AGU) | January 1st, 1989

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 12. River channel pattern comes in three flavors: straight, meander

Published by the American Geophysical Union as part of the Water Resources Monograph Series, Volume 12. River channel pattern comes in three flavors: straight, meandering, and braided. Of these, meandering is perhaps the most common, but at the same time the most mysterious: it is strikingly rich in pattern, yet is encumbered with neither the sterile order of its straight cousin, nor the undecipherable disorder of its braided relative. Consider Figures 1 and 2 herein. The former is of the artificially straightened Naka River, Shikoku, Japan. Thwarted in its quest for a meandering planform, the river has, nevertheless, generated of its own the precursor known as alternate bars. In the latter photograph, a pair of images of the East Nishnabotna River, Iowa, USA, illustrate the elegance of the sinuous river, and the inexorable migration and deformation of bends so characteristic of freely meandering streams.

Rivers of California

Pacific Gas & Electric Company (PG&E) | July 1st, 1962

Sacramento-San Joaquin Delta Atlas

California Department of Water Resources (DWR) | July 1st, 1995

The Delta of the Sacramento and San Joaquin rivers is California's water supply crossroads. It is the major collection point for water that serves over 20 million people,

The Delta of the Sacramento and San Joaquin rivers is California's water supply crossroads. It is the major collection point for water that serves over 20 million people, two-thirds of our State's population. The maze of islands and channels lying at the confluence of these two large rivers has long been the focal point of debate surrounding a number of complicated water-related issues of statewide importance. People with a wide variety of interests - agricultural, urban, industrial, environmental, and recreational-have a vital stake in the Delta and a need to understand the physical Delta and its complex interrelationships. This atlas provides information that we hope will be helpful in addressing the complex problems of the estuary. The atlas is a revision of the Sacramento-San Joaquin Delta Atlas that was published in 1987. It contains updates on many Delta facts and features. It also introduces new information on the Suisun Marsh and tides and hydrology in the Delta as well as in San Francisco Bay.

Safe Clean Water Water for Los Angeles County Residents

Los Angeles County Department of Public Works (LACDPW) | November 7th, 2017

We live in a water-scarce area, and forces outside of our control can threaten our local water resources, including lakes, rivers and beaches. LA Count

We live in a water-scarce area, and forces outside of our control can threaten our local water resources, including lakes, rivers and beaches. LA County residents rely heavily on imported water from the Sierra Mountains, the Central Valley and even from states as far away as Colorado. Climate change is causing more and more extreme weather conditions, making these remote sources more unreliable . The impacts of the recent five-year drought were widely felt here. Rainfall is an essential, local source of LA’s water . Rain runs through local rivers, creeks and streams and can be absorbed underground, replenishing groundwater, which is a local source of drinking water. However, because so much of our region is paved over, when we do experience heavy rain, too much of that precious water is lost to the ocean before we can capture it for use. Our local water resources are also threatened by toxins and pollution as stormwater runs through streets and over-paved areas into our rivers, creeks and streams. Pollution flows onto our beaches and into the ocean, posing a public health risk and harming marine life.