The System of the River: Francis Newlands and the Improbable Quest to Irrigate the West

Stanford University | June 28th, 2018

The tradeoff between water savings and salinization prevention in dryland irrigation

Advances in Water Resources (Elsevier) | December 7th, 2023

Soil salinization is a global phenomenon that affects large tracts of arid farmland worldwide. It contributes to the loss of soil fertility, declining yields, and – in

Soil salinization is a global phenomenon that affects large tracts of arid farmland worldwide. It contributes to the loss of soil fertility, declining yields, and – in the most severe cases – land unsuitability for cultivation. Irrigation water applications are both the main cause of and the solution to, anthropogenic (or ‘secondary’) salinization because salt typically enters the soil column as dissolved in irrigation water and leaves it through excess water applications (e.g., leaching). Excess leaching, which places additional water costs in areas affected by water scarcity, can be achieved with different irrigation techniques and practices. Here, by complementing a process-based crop water model with a salt balance of the shallow soil, we investigate the tradeoff between root zone salinization and water conservation to limit withdrawals from the water source. We evaluate how such a tradeoff is achieved under different irrigation technology and excess leaching practices. Considering as a case study the cultivation of tomatoes in Egypt, we find that drip and furrow irrigation allows for better control of salt accumulation, thus preventing crop exposure to salt stress. Drip irrigation achieves this goal with minimal water applications because it maintains the soil wetter. Thus, the (rare) rainfall events find more suitable conditions to drain the excess moisture. Conversely, by using more irrigation water (and ‘less efficiently’), furrow irrigation allows for higher rates of soil drainage and salt leaching. The irrigation schedule typically adopted with sprinkler irrigation allows for soil drying, thus limiting the ability of rainfall events to drain the soil and leach its salts. Collectively, these results highlight the key role of irrigation technology and practices in the management of secondary salinity in dryland agriculture. Specifically, there is a tradeoff between minimizing water use and preventing salt accumulation in the root zone. Drip irrigation exhibits the co-benefit of achieving both goals, while furrow irrigation limits soil salinity at the cost of requiring greater volumes of applied irrigation water.

The Transfer of Water Rights In California: Background and Issues

Governor's Commission to Review Water Rights Law | December 1st, 1977

This paper is part of a series of background and issue papers prepared by the staff of the Governor's Commission to Review Water Rights Law. TABLE OF CONTENTS I. 

This paper is part of a series of background and issue papers prepared by the staff of the Governor's Commission to Review Water Rights Law. TABLE OF CONTENTS I.  Water is a Marketable Resource II.  Legal Impediments to Water Rights Transfers in California III.  A Selective Review of Recent Water Rights Transfers in California IV.  Issues

The Treatment of Sediment-Carrying Mountain Streams in Europe, and its Application to California

Scientific American | September 12th, 1885

The debris question, so important to the interests of this State, is full of interesting features. It is of such intricate and complicate nature that only the most care

The debris question, so important to the interests of this State, is full of interesting features. It is of such intricate and complicate nature that only the most careful and impartial investigations of all the conditions bearing upon it can bring about its successful solution. The desire to contribute a small share to such has moved the writer to investigate what has been done in reference to sediment-carrying rivers, torrential streams, etc., in other parts of the world. The Alps in the southern and central part of Europe afford the best opportunity to study this question, as they have a great many such watercourses, which have damaged and partially continue to destroy the valleys by raising  the river bed and destroying adjoining agricultural ands by erosion or filling in. Certain portions of these, however, have been very successfully improved by comparatively simple and inexpensive means. The source of the detritus there is natural wash, and inno case hydraulic mining. In California the conditions are somewhat different, since the natural as well as the artificial source of the detritus must be considered.

The twenty-first century Colorado River hot drought and implications for the future

American Geophysical Union (AGU) | February 17th, 2017

Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15-year drought on record. At least one-sixth to one-half (averag

Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15-year drought on record. At least one-sixth to one-half (average at one-third) of this loss is due to unprecedented temperatures (0.9°C above the 1906–1999 average), confirming model-based analysis that continued warming will likely further reduce flows. Whereas it is virtually certain that warming will continue with additional emissions of greenhouse gases to the atmosphere, there has been no observed trend toward greater precipitation in the Colorado Basin, nor are climate models in agreement that there should be a trend. Moreover, there is a significant risk of decadal and multidecadal drought in the coming century, indicating that any increase in mean precipitation will likely be offset during periods of prolonged drought. Recently published estimates of Colorado River flow sensitivity to temperature combined with a large number of recent climate model-based temperature projections indicate that continued business-as-usual warming will drive temperature-induced declines in river flow, conservatively −20% by midcentury and −35% by end-century, with support for losses exceeding −30% at midcentury and −55% at end-century. Precipitation increases may moderate these declines somewhat, but to date no such increases are evident and there is no model agreement on future precipitation changes. These results, combined with the increasing likelihood of prolonged drought in the river basin, suggest that future climate change impacts on the Colorado River flows will be much more serious than currently assumed, especially if substantial reductions in greenhouse gas emissions do not occur.

The twenty‐first century Colorado River hot drought and implications for the future

American Geophysical Union (AGU) | February 17th, 2017

Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15‐year drought on record. At least one‐sixth to one‐half (

Between 2000 and 2014, annual Colorado River flows averaged 19% below the 1906–1999 average, the worst 15‐year drought on record. At least one‐sixth to one‐half (average at one‐third) of this loss is due to unprecedented temperatures (0.9°C above the 1906–1999 average), confirming model‐based analysis that continued warming will likely further reduce flows. Whereas it is virtually certain that warming will continue with additional emissions of greenhouse gases to the atmosphere, there has been no observed trend toward greater precipitation in the Colorado Basin, nor are climate models in agreement that there should be a trend. Moreover, there is a significant risk of decadal and multidecadal drought in the coming century, indicating that any increase in mean precipitation will likely be offset during periods of prolonged drought. Recently published estimates of Colorado River flow sensitivity to temperature combined with a large number of recent climate model‐based temperature projections indicate that continued business‐as‐usual warming will drive temperature‐induced declines in river flow, conservatively −20% by midcentury and −35% by end‐century, with support for losses exceeding −30% at midcentury and −55% at end‐century. Precipitation increases may moderate these declines somewhat, but to date no such increases are evident and there is no model agreement on future precipitation changes. These results, combined with the increasing likelihood of prolonged drought in the river basin, suggest that future climate change impacts on the Colorado River flows will be much more serious than currently assumed, especially if substantial reductions in greenhouse gas emissions do not occur.

The Twin Tunnels: Ruinous to Ratepayers, Catastrophic for the Environment

California Water Impact Network (C-WIN) | January 1st, 2014

Water is California’s most essential resource. It is limited in availability—in some years, extremely limited, forcing devastating delivery cut-backs to cities, farms

Water is California’s most essential resource. It is limited in availability—in some years, extremely limited, forcing devastating delivery cut-backs to cities, farms and the environment. A recent paper in Frontiers in Ecology and the Environment concludes that the average flow in the Sacramento River—the state’s major source for developed surface water—could decrease by 20 percent by 2050 largely due to climate change. By that same year, California’s population is expected to top 50 million, up from the current figure of 38 million. In other words, our water supplies will dwindle as our population burgeons. Meanwhile, the state’s water delivery policies are already demonstrably incapable of providing water to citizens, agriculture and commerce while simultaneously sustaining essential ecosystems. In response, Governor Jerry Brown and his allies in the state legislature and agribusiness are promoting the “Twin Tunnels” boondoggle: a massive conveyance system that will shunt water under the Sacramento/San Joaquin Delta to the south state.

The U.S. Infrastructure Investment and Jobs Act: Water Components

Pacific Institute | November 12th, 2021

On November 5, 2021, the U.S. Congress passed President Biden’s major infrastructure bill, HR 3684, the $1.2 trillion Infrastructure Investment and Jobs Act. The Presid

On November 5, 2021, the U.S. Congress passed President Biden’s major infrastructure bill, HR 3684, the $1.2 trillion Infrastructure Investment and Jobs Act. The President is expected to sign the bill into law. The bill is the largest single federal investment in infrastructure in a generation, with the funds to be expended over five years. It aims to rebuild and replace failing, aging, and outdated water, energy, transportation, and communications systems. As the first significant federal investment in climate resilience, it also begins to address the growing consequences of climate change, including intensifying extreme weather events, increasing temperatures, and rising sea levels, on communities throughout the United States. One key component of the Act is the set of proposals to address the wide range of water-related challenges facing the United States. This Pacific Institute analysis provides an overview of how the Infrastructure Act addresses these challenges.

The Unaffordable and Unsustainable Twin Tunnels: Why the Santa Barbara Experience Matters

California Water Impact Network (C-WIN) | July 1st, 2016

PURPOSE OF THIS REPORT 1. Examine the deficiencies and cost impacts of Governor Brown's Twin Tunnels/CA WaterFix, illustrating the untenable financial burden these pro

PURPOSE OF THIS REPORT 1. Examine the deficiencies and cost impacts of Governor Brown's Twin Tunnels/CA WaterFix, illustrating the untenable financial burden these proposals place on local water agencies and ratepayers; 2. Highlight that the Tunnels/CA WaterFix will not provide more water when needed, i.e., during drought; 3. Explain the unintended consequences of participation in the State Water Project (SWP) utilizing the experience of Santa Barbara County as an example of the statewide problem; 4. Highlight the exorbitant cost and unreliability of importing water from the State Water Project (SWP) to the communities of Santa Barbara's South Coast.

The unequal burdens of water scarcity

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

Curtailing water use during drought is costly, but those costs are not evenly distributed. Socio–hydrological modelling shows how water burdens fall more heavily on poo

Curtailing water use during drought is costly, but those costs are not evenly distributed. Socio–hydrological modelling shows how water burdens fall more heavily on poor households in response to water conservation policies.