Irrigation Improvement Continuum

Limited water supplies — with or without the California drought — are a reality. Almond Board of California has invested heavily in the area of water irrigation strategies and technologies that conserve water while optimizing almond production and tree health, as well as in ways to protect ground-and surface-water from potential runoff or leaching of grower inputs.

One of these investments is the Almond Irrigation Improvement Continuum; a comprehensive manual of irrigation management and scheduling practices. Recognizing that growers may be operating at different stages of irrigation efficiency, the Continuum provides information at three proficiency levels (1.0, 2.0 and 3.0), each covering the following concepts and how to execute and effectively integrate them: 

  • Measuring irrigation system performance and efficiency
  • Estimating orchard water requirements based on evapotranspiration
  • Determining the water applied
  • Evaluating soil moisture
  • Evaluating plant water status

The Irrigation Continuum was developed in partnership with the many trusted and respected technical experts and resources available, such as University of California Division of Agriculture and Natural Resources Cooperative Extension. Please email Spencer Cooper, for an in-the-orchard visit or phone consultation. Spencer's support allows for system-specific recommendations to increase the "crop per drop" on an orchard-by-orchard basis.

Almond Irrigation Improvement Continuum 1.0

The Continuum Level 1.0 outlines irrigation management practices that are within reach for all California Almond growers. It is available as a downloadable PDF and downloadable EPUB to read on a digital reader app through your tablet or smart phone.

In addition to the manual, there are one page summary documents from sections within the manual.



Almond Irrigation Improvement Continuum 2.0 and 3.0

While the above tools are available now, development of the Continuum continues with respected irrigation experts to build out levels 2.0 and 3.0.

The Continuum Level 2.0 consists of more intermediate level practices and Level 3.0 address practices at more sophisticated levels to attain even more “crop per drop.” As Level 2.0 and 3.0 manuals are developed, they will be published on this web page. If you would like a notification when the new manuals are published, please submit your email address and specify 2.0 and/or 3.0.

Why is Irrigation Improvement a Priority?

In 2015, Almond Board of California’s (ABC) Board of Directors adopted Water Management and Efficiency as one of four key components of the Accelerated Innovation Management (AIM) program. ABC has long been a research-based organization and will continue to support traditional research and sustainability initiatives, but is now placing greater emphasis on the innovative almond farming practices that will be required to meet the future needs of the California almond industry, as well as the consumer, the community and the planet.

The Water Management and Efficiency initiative focuses on accelerating almond grower transition and adoption of research based, commercially available, and increasingly water efficient irrigation management and scheduling tools. 

Irrigation Calculator

The Irrigation Calculator supports the practices in the Irrigation Continuum and generates irrigation run time schedules that advise the amount and timing of irrigations based on local evapotranspiration and information about your individual orchard and irrigation system. Linked to your nearest CIMIS station, this tool automatically integrates current weather information, allowing you to better calculate your orchard’s irrigation water requirement.  The tool can be accessed on the California Almond Sustainability Program website and is referenced throughout Almond Irrigation Continuum 1.0. 

The scheduling tool stores data by orchard block, making updates easy as information changes. It’s also completely private — information is not shared with anyone. Data entered into the Irrigation Calculator can be saved and updated as necessary. All almond growers can use the Calculator to create irrigation schedules, but must be participants in the California Almond Sustainability Program for the data storage aspect, which saves the need to reenter all the data when making revisions during the growing season. Data can be printed or displayed as a PDF file, or exported into a database.

Hullsplit Strategic Deficit Irrigation

Almond trees can tolerate moderate drought stress from the completion of kernel fill to 90% hullsplit without risk of crop loss or long-term yield effects. Moderate water stress at this time provides three additional benefits: 1) lower potential for hull rot2) a more uniform hullsplitleading to an earlier harvest, when crop damage from rainfall is less likely; and 3) an earlier harvest, all of which can help minimize crop exposure to late-season navel orangeworm flights and potential aflatoxin contamination.

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Water Supply

Water Sources and Infrastructure

California’s Mediterranean climate is conducive to producing high-yielding, high-quality almond crops year-in and year-out. While these ideal growing conditions form the backdrop for the state’s almond-growing productivity, it is our ability to store and distribute water for irrigation during the dry growing season that is the key to this success.

With rain and snow falling almost exclusively in the winter and early spring and mostly in the northern part of the state, Californians rely on an intricate system of dams that create reservoirs for storage, and canals to distribute stored water as needed to irrigate crops, as well as support health and human services, industry, recreation and environmental concerns. The snowpack in the Sierra Nevada mountains acts as an additional water storage device, recharging rivers, reservoirs and groundwater supplies as it slowly melts during the dry months. Underground aquifers, sustained by that same Sierra snowpack, provide an additional source of water that is tapped by wells for irrigation and other uses.

Several issues affect the state’s water supplies:

  • Sustained population growth throughout California
  • Lower-than-average rainfall and a thin snowpack in recent years that have reduced the amount of water in storage, both aboveground and underground
  • An aging and inadequate storage and delivery system that cannot meet the state’s multiuse water needs
  • The failing of the infrastructure of the Sacramento–San Joaquin River Delta, the “crossroads” of the state’s water delivery system
  • Legal and environmental issues, such as the protection of endangered species, that require Delta pumps to be shut down during critical periods of water delivery.

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Water Quality

Almond growers rely on good water quality to ensure both a healthy tree and a healthful crop. Growers also need to protect surface- and groundwater from runoff, spray drift and/or leaching by following good management practices.


Almonds have a relatively low tolerance for saline conditions; however, the nature of irrigated agriculture is that salts carried in the irrigation water are added to the soils and accumulate there. Different water sources carry different levels of salts. For example, groundwater on the West Side of the San Joaquin Valley is generally naturally high in salts, while surface water from snowmelt is very low in salts. Depending on the sources of water available to the grower, a part of irrigation management is to ensure enough good-quality water is applied to leach salts below the root zone. Minimizing the addition of salt to the soil and removing salts by leaching are critical for continued almond production.

There is an inherent conflict between the goals of maintaining groundwater quality while maintaining a productive irrigated agriculture. These issues are being addressed by the Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS). CV-SALTS members include entities involved with water management, irrigation districts and some growers, as well as the Central Valley Regional Water Quality Control Board.

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Groundwater Protection

Growers in California have recently been tasked with protecting groundwater quality under the Irrigated Lands Regulatory Program.

Groundwater quality issues include nitrates that primarily come from agriculture, salinity that is often naturally occurring, a few pesticide issues (primarily legacy issues) and issues such as arsenic, which is primarily from natural sources.

Monitoring of groundwater in the Central Valley has detected a number of sites with elevated nitrate levels. Nitrates affect the ability to use the water for drinking. Nitrate is a form of nitrogen that plants can take up as one of their nutrients; however, it also moves easily in water and therefore leaches easily into groundwater. The Central Valley Regional Water Quality Control Board, under the Irrigated Lands Regulatory Program, has developed a Groundwater Quality Protection Strategy that addresses the issue of nitrates and other contaminants in groundwater. With some care, growers can minimize — but not necessarily eliminate — nitrate leaching from their fertilization practices.

The nitrogen budget calculator at the California Almond Sustainability Program website is a tool that growers can use to more precisely apply nitrogen to orchards in the amounts that the crop demands, resulting in less potential nitrogen leaching into groundwater.

In some instances, pesticides have shown up in groundwater. Currently, California’s Department of Pesticide Regulation (CDPR) limits the use of pesticides that have the potential to leach in areas where the groundwater is more vulnerable; these are called Ground Water Protection Areas (GWPA). In addition, CDPR monitors for pesticides that could possibly leach, based on their chemical characteristics.

Preventing Irrigation and Storm Water Runoff

A comprehensive surface water–quality regulation for agriculture in the Central Valley of California was passed in 2003 by the Central Valley Regional Water Quality Control Board. Through participation in the Irrigated Lands Regulatory Program watershed coalitions throughout the San Joaquin Valley, almond growers are meeting their legal requirements under the Clean Water Act to protect water quality. The coalitions also help almond growers take steps to reduce potential levels of farm waste in irrigation drainage or rainwater runoff.

Monitoring and ultimately reducing discharges of pesticides, nutrients and sediments into waterways and groundwater is the goal of almond growers in California’s Central Valley. To help them meet that goal, the Almond Board of California funds research on ways to control runoff from orchards and prevent it from contaminating surface and groundwater.

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