The Effect of Declining Groundwater Levels on Supply Well Operations

University of California, Davis (UC Davis) | August 15th, 2016

This report explores the impact of droughts on domestic and irrigation well operations. Well completion reports and groundwater depth data obtained from the Department of

This report explores the impact of droughts on domestic and irrigation well operations. Well completion reports and groundwater depth data obtained from the Department of Water Resources were used in the analysis. The percentages of wells in which the top, middle or bottom of the screened interval became exposed above the pumping water level were calculated and implied maintenance or replacement costs were estimated. Increases in pumping costs from greater depths to groundwater were estimated as well. For our case study, we selected a 27 square mile area in Tulare County, where the California Department of Water Resources has determined that groundwater is in a state of critical overdraft and designated the basin as High Priority under the Sustainable Groundwater Management Act. Results indicate that for the 2015 drought, there was significant potential for incurring well maintenance and replacement costs as a result of drought conditions and water levels approaching critical points in the screened intervals. While the assumptions associated with the current method appear to result in overestimation of impacts, the current drought may have resulted in several million dollars in well maintenance and replacement costs. For irrigation wells that remained in operation, increased depths to groundwater would increase overall pumping costs. About $5.31 per acre ($1.7 per acre-foot) were estimated as increased pumping costs in the recent 2012-2015 drought. While these costs are not large on a per acre basis, they may be significant when incurred across large agricultural areas. This proof of concept analysis highlights the value of information on groundwater levels and well constructions for estimating impacts of droughts on long term groundwater pumping capacity and operation. This analysis can be extended for the entire Central Valley in an effort to quantify the impacts of drought and the importance of groundwater management.

The irrigation efficiency trap: rational farm-scale decisions can lead to poor hydrologic outcomes at the basin scale

Frontiers in Environmental Science | August 28th, 2023

Agricultural irrigation practices have changed through time as technology has enabled more efficient conveyance and application. In some agricultural regions, irrigation

Agricultural irrigation practices have changed through time as technology has enabled more efficient conveyance and application. In some agricultural regions, irrigation can contribute to incidental aquifer recharge important for groundwater return flows to streams. The Henrys Fork Snake River, Idaho (United States) overlies a portion of the Eastern Snake Plain Aquifer, where irrigated agriculture has occurred for over a century. Using irrigator interviews, aerial and satellite imagery, and statistical streamflow analysis, we document the impact of farm-scale decisions on basin-scale hydrology. Motivated to improve economic efficiency, irrigators began converting from surface to center-pivot sprinkler irrigation in the 1950s, with rapid adoption of center-pivot sprinklers through 2000. Between 1978–2000 and 2001–2022, annual surface-water diversion decreased by 311 Mm3 (23%) and annual return flow to the river decreased by 299 Mm3 over the same period. Some reaches that gained water during 1978–2000 lost water to the aquifer during the later period. We use an interdisciplinary approach to demonstrate how individual farm-scale improvements in irrigation efficiency can cumulatively affect hydrology at the landscape scale and alter groundwater-surface water relationships. Return flows are an important part of basin hydrology in irrigated landscapes and we discuss how managed and incidental aquifer recharge can be implemented to recover return flows to rivers.

The New Inland Sea

Scientific American | April 13th, 1907

The deep channel in the Alamo River, which passed Holtville in August, was gradually approaching Sharp's Heading, and it was recognized that when this cataract reached

The deep channel in the Alamo River, which passed Holtville in August, was gradually approaching Sharp's Heading, and it was recognized that when this cataract reached the heading it would be very difficult and expensive, and perhaps impossible, to maintain that heading. This, however, was not the only peril to the water supply of the valley. The channel of New River had eroded to such an extent that where the two streams separated it was estimated that four-fifths of the water was running down New River and only one fifth down the Alamo. While this proportion was favorable to the regimen of the Alamo and the safety of Sharp's Heading, it was very threatening in an other respect. It accelerated the cutting of the New River channel, in which was a great cataract four or five miles below the separation of the two streams, and this was, of course, advancing upstream. It was well recognized that when this cataract reached the Alamo the channel would be so deep that all of the water would run down New River and leave Sharp's Heading on dry land, without any water for the irrigation of the Imperial Valley. Threatened first with inundation, and next with the destruction of their entire water supply, the inhabitants of the Imperial Valley have naturally been almost in a state of panic for several months.

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.

Transition from irrigation with untreated wastewater to treated wastewater and associated benefits and risks

Nature Portfolio (Springer Nature) | January 26th, 2025

Investments in “Clean water and sanitation” drive a transition from irrigation with untreated to irrigation with treated wastewater. While this transition reduces man

Investments in “Clean water and sanitation” drive a transition from irrigation with untreated to irrigation with treated wastewater. While this transition reduces many health risks, it may decrease crop yields, and soil carbon storage, cause a release of accumulated pollutants from soils, and increase the spread of antibiotic resistance in the environment. A holistic view on multiple SDGs is necessary to maximize benefits and minimize risks of wastewater treatment for irrigation.

Wastewater Reuse for Agriculture: Development of a Regional Water Reuse Decision-Support Model (RWRM) for Cost-Effective Irrigation Sources

American Chemical Society (ACS) | August 8th, 2016

Water scarcity has become a critical problem in many semiarid and arid regions. The single largest water use in such regions is for crop irrigation, which typically relie

Water scarcity has become a critical problem in many semiarid and arid regions. The single largest water use in such regions is for crop irrigation, which typically relies on groundwater and surface water sources. With increasing stress on these traditional water sources, it is important to consider alternative irrigation sources for areas with limited freshwater resources. One potential irrigation water resource is treated wastewater for agricultural fields located near urban centers. In addition, treated wastewater can contribute an appreciable amount of necessary nutrients for plants. The suitability of reclaimed water for specific applications depends on water quality and usage requirements. The main factors that determine the suitability of recycled water for agricultural irrigation are salinity, heavy metals, and pathogens, which cause adverse effects on human, plants, and soils. In this paper, we develop a regional water reuse decision-support model (RWRM) using the general algebraic modeling system to analyze the cost-effectiveness of alternative treatment trains to generate irrigation water from reclaimed wastewater, with the irrigation water designed to meet crop requirements as well as California’s wastewater reuse regulations (Title 22). Using a cost-minimization framework, least-cost solutions consisting of treatment processes and their intensities (blending ratios) are identified to produce alternative irrigation sources for citrus and turfgrass. Our analysis illustrates the benefits of employing an optimization framework and flexible treatment design to identify cost-effective blending opportunities that may produce high-quality irrigation water for a wide range of end uses.

Water Use by Urban Lawns and Trees in Los Angeles

University of California, Los Angeles (UCLA) | July 24th, 2017

Wells of Southern California

Scientific American | March 22nd, 1902

In the Series of Water Supply Irrigation Papers, the United States Geological Survey has in press, but not yet published, the “Wells of Southern California" (Nos. 59

In the Series of Water Supply Irrigation Papers, the United States Geological Survey has in press, but not yet published, the “Wells of Southern California" (Nos. 59 and 60), by Mr. Joseph Barlow Lippincott. In his letter of transmittal Mr. F.H. Newell, Hydrographer in Charge, remarks: "The results are instructive, as showing what may be done in other parts of the United States under favorable conditions of climate and soil, and have peculiar interest in any consideration of the extent to which the arid land can ultimately be redeemed by irrigation." The region discussed is the San Bernardino Valley in Southern California, which has an area of 563 square miles, and lies south and west of the Sierra Madre and San Bernardino Mountains. Riverside and Rcdlands are the centers of fruit production. Up to elevations of 2,000 feet the relatively high lands are free from frost, and the relatively low lands are subject to it. The distinctive crop of San Barnardino Valley is citrus fruits. Oranges predominate, followed next by lemons, and of late years the grape fruit has become a popular product. Olives, almonds, prunes, apricots, peaches, pears, and wine, raisin, and table grapes, are all grown to perfection in this district. In the eleven years prior to 1898 Riverside shipped nearly seven million boxes of oranges, an average annual income of $1,000,000. Water is the lifeblood of the land.