Inyo County: Monitoring Groundwater Dependent Vegetation to Inform Groundwater Management

Nature Conservancy | August 1st, 1989

Inyo County and the City of Los Angeles have shown innovative and progressive leadership in the protection of groundwater dependent ecosystems in Owens Valley,

Inyo County and the City of Los Angeles have shown innovative and progressive leadership in the protection of groundwater dependent ecosystems in Owens Valley, and thanks to a landmark agreement between Inyo County and the Los Angeles Department of Water and Power (LADWP), the outlook for groundwater dependent ecosystems (GDEs) in this area is promising. In 1991, the Inyo/Los Angeles Long-Term Water Agreement (Agreement) established an elaborate system to manage groundwater pumping by LADWP to avoid substantial declines in groundwater dependent vegetation in the Owens Valley. Implemented to settle the County’s 1971 CEQA challenge of LADWP’s proposed method to fill its second aqueduct, the Agreement resolved years of litigation between the County and LADWP.

Irregular Focal Mechanisms Observed at Salton Sea Geothermal Field: Possible Influences of Anthropogenic Stress Perturbations

Stanford University | February 12th, 2018

At the Salton Sea Geothermal Field (SSGF), strain accumulation is released through seismic slip and aseismic deformation. Earthquake activity at the SSGF often oc

At the Salton Sea Geothermal Field (SSGF), strain accumulation is released through seismic slip and aseismic deformation. Earthquake activity at the SSGF often occurs in swarm-like clusters, some with clear migration patterns. We have identified an earthquake sequence composed entirely of focal mechanisms representing an ambiguous style of faulting, where strikes are similar but deformation occurs due to steeply-dipping normal faults with varied stress states. In order to more accurately determine the style of faulting for these events, we revisit the original waveforms and refine estimates of P and S wave arrival times and displacement amplitudes. We calculate the acceptable focal plane solutions using P-wave polarities and S/P amplitude ratios, and determine the preferred fault plane. Without constraints on local variations in stress, found by inverting the full earthquake catalog, it is difficult to explain the occurrence of such events using standard fault-mechanics and friction. Comparing these variations with the expected poroelastic effects from local production and injection of geothermal fluids suggests that anthropogenic activity could affect the style of faulting.

Irrigated agricultural adaptation to water and climate variability: The economic value of a water portfolio

Journal of Agricultural Economics (Wiley) | December 1st, 2014

Increasing aridity, more frequent and intense drought, and greater degrees of water scarcity create unique challenges for agriculture. In response to these challenges, wh

Increasing aridity, more frequent and intense drought, and greater degrees of water scarcity create unique challenges for agriculture. In response to these challenges, which often manifest themselves as lower and more variable surface water supplies, as well as depleted and degraded ground water supplies, growers tend to seek opportunities to adapt. One option for growers to reduce their exposure to water scarcity and heightened uncertainty is to diversify. Indeed, access to a portfolio of supplies is one way in which water and irrigation districts, as well as individual growers, are responding to the changing landscape of water resource availability. This article evaluates the benefits to irrigated agriculture from having access to multiple sources of water. With farm-level information on 1,900 agricultural parcels across California, we use the hedonic property value method to investigate the extent that growers benefit from having access to multiple sources of water (i.e., a water portfolio). Our results suggest that while lower quality waters, less reliable water, and less water all negatively impact agricultural land values, holding a water portfolio has a positive impact on land values through its role in mitigating the negative aspects of these factors and reducing the sensitivity of agriculture to climate-related factors. From a policy perspective, such results identify a valuable adaptation tool that irrigation districts may consider to help offset the negative impacts of climate change, drought, and population increases on water supply availability and reliability.

Irrigated Agriculture Technologies, Practices, and Implications for Water Scarcity

U.S. Government Accountability Office (GAO) | November 12th, 2019

Demand for freshwater surpasses the amount naturally available in some areas of the United States. The agriculture sector competes for this limited resource, and withdraw

Demand for freshwater surpasses the amount naturally available in some areas of the United States. The agriculture sector competes for this limited resource, and withdraws and consumes the most freshwater of any user in the nation. GAO was asked to conduct a technology assessment around agricultural water use. This report provides an overview of irrigation technologies and on-farm water conservation practices, factors influencing the adoption of these technologies, and implications of their use for water scarcity. In conducting this assessment, GAO reviewed scientific literature; convened an expert meeting with the assistance of the National Academies; visited farmers, academics, and industry representatives; interviewed officials from federal agencies; modeled water use in an illustrative watershed; and performed a regression analysis on U.S. Department of Agriculture irrigation, crop, and technology data. GAO describes two policy options that federal policymakers could consider relating to irrigation technology and discusses their benefits and challenges.

Irrigating Machinery on the Pacific Coast

Scientific American | December 17th, 1887

In offering the present paper to the Institution of Mechanical Engineers, the author does so with a tolerably complete knowledge of the very advanced practice in England

In offering the present paper to the Institution of Mechanical Engineers, the author does so with a tolerably complete knowledge of the very advanced practice in England in this class of machinery: and his purpose is mainly to explain the differences that have been called for by local circumstances in California. Character of the Country: The western or Pacific slope of the Sierra Nevada or coast range of mountains in California is very abrupt, the crests of the range being so near that the snow is visible from the coast during the whole year. Hundreds of streams cross this narrow country, falling either direct into the Pacific Ocean or into the great basin formed by the Sacramento and San Joaquin rivers. These two rivers. the largest in California, run in opposite directions nearly parallel with the coast and meet at the Bay of San Francisco forming ac ontinuous valley 400 miles long and from 50 to 100 miles wide. The small streams for the most part are fed by melting snow in the summer; and every gulch or canon has its rivulet or brook. They increase in volume until they pass into or through the hills at the foot of the mountain range; and there, unless of considerable size, they may wholly disappear in summer by percolation through the silt or by evaporation. Streams exposed to the torrid air which in summer sweeps across the sand deserts of Southern California are dried up with wonderful rapidity. The evaporation from Salt Lake, exposed to the same dry wind, is sometimes equal to half an inch per day. or 64 million tons of water. Not withstanding this great loss by evaporation, the quantity of water falling into the ocean on the coast of California has been estimated at 100 million cubic feet or 2 3/4 million tons per minute, enough, if distributed properly, to irrigate 25,000 square miles.

Irrigation

Scientific American | January 10th, 1903

Irrigation has been practised in America from time immemorial by the town-building Pueblo Indian tribes inhabiting portions of New Mexico and Arizona. Their ancie

Irrigation has been practised in America from time immemorial by the town-building Pueblo Indian tribes inhabiting portions of New Mexico and Arizona. Their ancient canals may still be traced across the broad valleys. through which are scattered the almost innu merable ruins of community dwellings. On the mesas of southwestern Colorado and adjacent portions of Utah, Arizona, and New Mexico are found the wonderful cliff dwellings, and in the little valleys near these may be seen ditches which were in use perhaps a thousand or more years ago.

Irrigation

Scientific American | January 17th, 1903

Irrigation in California

Scientific American | January 4th, 1890

Irrigation in California

Scientific American | January 5th, 1884

Irrigation in Southern California

Scientific American | December 17th, 1904

As an example of the beneficent results of irrigation of desert lands, a project which has been undertaken in Southern California is probably one of the most notable i

As an example of the beneficent results of irrigation of desert lands, a project which has been undertaken in Southern California is probably one of the most notable in America, for its promoters selected a region most of which was entirely devoid of vegetation in any form, the soil, if it can be called such, not even containing enough elements of fertility to nourish the sparse vegetation found in the so-called desert of the Southwest. Prior to the reclamation of this land, one could travel for miles without seeing any vegetation. Most of the area referred to forms a part of the Colorado Valley, and is situated in San Diego County. The head of the canal was located on the river at a point seven miles west of Yuma, Arizona, and but a short distance from the boundary between California and Mexico. Here the elevation is 120 feet above sea level, a sufficient altitude to give an average fall of from four to six feet to the mile. It was found impossible to construct the waterway in a straight line, owing to the topography of the country, and in its course it makes a wide detour, passing through a portion of the Mexican republic. It is unique from the fact that it is probably the only international irrigation canal in the world, the water being used to cultivate a considerable area in the southern republic.