Agricultural Water Conservation and Efficiency Potential in California
Keywords:agriculture, agriculture water use and efficiency
California Water Plan 2013: Sacramento River Hydrologic Region Report$0.00 Bulk Download
California Water Plan 2013: Sacramento River Hydrologic Region ReportCalifornia Department of Water Resources (DWR) | October 30, 2014...Summary
The Sacramento River Hydrologic Region (see Figure SR-1 includes the entire California drainage area of the Sacramento River (the state’s largest river) and...
The Sacramento River Hydrologic Region (see Figure SR-1 includes the entire California drainage area of the Sacramento River (the state’s largest river) and its tributaries. The region extends from Chipps Island in Solano County north to Goose Lake in Modoc County. It is bounded by the Sierra Nevada on the east, the Coast Ranges on the west, the Cascade and Trinity mountains on the north, and the Sacramento-San Joaquin River Delta (Delta) on the south. The Sacramento River Basin actually begins in Oregon, north of Goose Lake, a near-sink that intercepts the Pit River drainage at the California-Oregon border.
Some key issues for this region are summarized here and discussed further later in this report.
Agriculture. Between 2005 and 2010, the region supported about 1.95 million acres of irrigated agriculture on average. Approximately 1.58 million acres is irrigated on the valley floor. The surrounding mountain valleys add about 370,000 irrigated acres to the region’s total — primarily as pasture and alfalfa. The gross value of agricultural production in the Sacramento Valley for 2011 was about $4.1 billion (California Department of Food and Agriculture 2013). Rice and walnuts are the highest grossing crops in the region followed by almonds and tomatoes. The direct, indirect, and induced effects of the agricultural industry to the regional economy are discussed in this report.
Groundwater. With a 2005-2010 average annual extraction volume of 2.7 million acre-feet (maf), groundwater pumping in the Sacramento River Hydrologic Region accounts for 17 percent of all the groundwater extraction in California — the third highest among the 10 hydrologic regions in California, behind Tulare Lake Hydrologic Region with 38 percent and San Joaquin River Hydrologic Region with 19 percent of the total. Overall, groundwater contributes to about 31 percent of the total water supply. Most groundwater extraction in the region occurs for agricultural water use (2.4 maf), meeting about one-third of agricultural water demands. Groundwater extraction for urban water use is significantly less (465 thousand acre-feet [taf]), which meets about half of the urban water needs. Groundwater levels for much of the region have declined from 2005 to 2010. Groundwater level declines ranging from 20 to 30 feet are seen in the northwestern portion of the Sacramento Valley Groundwater Basin. Declines ranging from to 10 to 20 feet are seen in the northern, the mid- to south-western, and the southeastern portions of the valley. For the rest of the Sacramento Valley Groundwater Basin and the Redding Area Groundwater Basin, groundwater level declines have
ranged from zero to 10 feet.
Flood. Exposure to a 500-year flood event in the region threatens approximately one in three residents, almost $65 billion in assets (crops, buildings, and public infrastructure), 1.2 million acres of agricultural land, and over 340 sensitive species. Almost 95 percent of Sutter County residents, more than 55 percent of Yuba County and Yolo County residents, and more than 50 percent of agricultural land region-wide are exposed to the 500-year flood event.
Climate Change. Several different climate regions overlie portions of the Sacramento River Hydrologic Region. Air temperature data collected for the past century has been summarized by the Western Regional Climate Center (WRCC) for the different regions which are outlined below.
- Within the WRCC North Central climate region, mean temperatures have increased by about 0.8 to 1.7 °F (0.4 to 0.9 °C) in the past century, with minimum and maximum temperatures increasing by about 1.2 to 2.1 °F (0.7 to 1.2 °C) and 0.1 to 1.5 °F (0.1 to 0.8 °C), respectively.
- Within the WRCC North East climate region, mean temperatures have increased by about 0.8 to 2.0 °F (0.5 to 1.1 °C) in the past century, with minimum and maximum temperatures increasing by about 0.9 to 2.2 °F (0.5 to 1.2 °C) and by 0.5 to 2.1 °F (0.3 to 1.2 °C), respectively.
- Within the WRCC Sierra climate region, mean temperatures have increased by about 0.8 to 2.0 °F (0.5 to 1.1 °C) in the past century, with minimum and maximum temperatures increasing and decreasing by about 1.7 to 2.8 °F (0.9 to 1.5 °C) and by -0.2 to 1.3 °F (-0.1 to 0.7 °C), respectively.
- Within the WRCC Sacramento-Delta climate region, mean temperatures have increased by about 1.5 to 2.4 °F (0.9 to 1.3 °C) in the past century, with minimum and maximum temperatures increasing by about 2.1 to 3.1 °F (1.2 to 1.7 °C) and by 0.8 to 2.0 °F (0.4 to 1.1 °C), respectively (Western
Regional Climate Center 2013).
The region also is currently experiencing impacts from climate change through changes in statewide precipitation and surface runoff volumes, which in turn affect availability of local and imported water supplies. During the last century, the average early snowpack in the Sierra Nevada decreased by about 10 percent, which equates to a loss of 1.5 maf of snowpack storage (California Department of Water Resources 2008). Projections and impacts based on modeling of climate change are included in this report.
Addressing Nitrate in California’s Drinking Water with a Focus on Tulare Lake Basin and Salinas Valley Groundwater$0.00 Bulk Download
Addressing Nitrate in California’s Drinking Water with a Focus on Tulare Lake Basin and Salinas Valley GroundwaterUniversity of California, Davis (UC Davis) | March 1, 2012...Summary
In 2008, Senate Bill SBX2 1 (Perata) was signed into law (Water Code Section 83002.5), requiring the State Water Resources Control Board (State...
In 2008, Senate Bill SBX2 1 (Perata) was signed into law (Water Code Section 83002.5), requiring the State Water Resources Control Board (State Water Board), in consultation with other agencies, to prepare a Report to the Legislature to “improve understanding of the causes of [nitrate] groundwater contamination, identify potential remediation solutions and funding sources to recover costs expended by the State to clean up or treat groundwater, and ensure the provision of safe drinking water to all communities.”
The University of California prepared this Report under contract with the State Water Board as it prepares its Report to the Legislature. This executive summary focuses on major findings and promising actions. Details can be found in the Main Report and eight accompanying Technical Reports.
Technical Report 1: Project and Technical Report Outline (Version July 2012)
Technical Report 2: Nitrogen Sources and Loading to Groundwater (Version July 2012)
Appendix, Technical Report 2: Appendix Figures to Technical Report 2 (Version July 2012) - 84 MB (large file)
Technical Report 3: Nitrogen Source Reduction to Protect Groundwater Quality (Version July 2012)
Technical Report 4: Groundwater Nitrate Occurrence (Version July 2012)
Technical Report 5: Groundwater Remediation and Management for Nitrate (Version July 2012)
Technical Report 6: Drinking Water Treatment for Nitrate (Version July 2012)
Technical Report 7: Alternative Water Supply Options for Nitrate Contamination (Version July 2012)
Technical Report 8: Regulatory and Funding Options for Nitrate Groundwater Contamination
Salt Tolerance of Crops in the Southern Sacramento-San Joaquin Delta$0.00 Bulk Download
Salt Tolerance of Crops in the Southern Sacramento-San Joaquin DeltaCalifornia State Water Resources Control Board | January 5, 2010...Summary
The purpose of this report is to research the scientific literature and provide the state of knowledge on subjects that impact crop productivity...
The purpose of this report is to research the scientific literature and provide the state of knowledge on subjects that impact crop productivity with saline irrigation water and analyze the existing information from the South Delta and quantify how the various factors influencing the use of saline water applies to conditions in the South Delta.
There are five objectives for this study:
One of the objectives of this study is the review of existing literature relating to the effect of salinity on a variety of irrigated crops under South Delta conditions, preparation of a comprehensive list of references, and a synopsis of findings from key references.
A second objective is the review of the relative strengths and limitations of steady-state and transient models that have been used to determine the suitability of saline water for crop production. As part of this second objective, the strengths, limitations, and assumptions of each model when applied to field conditions are to be presented.
The third objective involves the use of soil information to determine and describe the approximate area and nature of saline and drainage-impaired soils; an estimate of the effectiveness of local rainfall in reducing the irrigation requirement; and compiling and evaluating historical crop types, acreages, and evapotranspiration information.
The fourth objective is to provide conclusions and recommendations to the State Water Resources Control Board based upon the literature, modeling, and data evaluation. Among the conclusions and recommendations to be reported the following are considered paramount. (1) Identify significant gaps or uncertainties in the literature and recommend future studies to fill the gaps. (2) Using a steady-state model and appropriate data for the South Delta, estimate the leaching fraction required for salinity control for crops regularly grown on the drainage- and salinity-impaired soils of the South Delta. (3) Using the approach as in (2), recommend a salinity guideline that could provide full protection of the most salt sensitive crop currently grown or suitable to be grown on the drainage- and salinity- impaired soils.
The final objective is to present the findings and recommendations in Sacramento to interested stakeholders and representatives of California state agencies.
Irrigation in U.S. Agriculture: On-Farm Technologies and Best Management Practices$0.00 Bulk Download
Irrigation in U.S. Agriculture: On-Farm Technologies and Best Management PracticesCongressional Research Service | October 17, 2016...Summary
Recent threats to water availability as a result of moderate to exceptional drought in several states have raised questions about agricultural water use...
Recent threats to water availability as a result of moderate to exceptional drought in several states have raised questions about agricultural water use and efficiencies across the United States. An understanding of common irrigation technologies and the impacts of best management practices in irrigation may be useful to Congress concerning potential policy responses to this issue. As a major user of water, the agricultural industry’s use of water resources continues to be a focal point of agriculture policy. Additional demands on water supplies, extreme weather events (e.g., prolonged drought), and agricultural market conditions have raised producers’ interest in investing in irrigation systems. Increased pressure on the industry to reduce its water use has also drawn interest in the adoption of irrigation technologies and best management practices (BMPs) as a means of achieving efficiency and potential water savings.
The federal government performs several roles in assisting agricultural producers with irrigation practices, including financial assistance, technical assistance, research, and monitoring and reporting. The majority of financial and technical assistance is offered through voluntary conservation programs that target increased irrigation efficiency. In some cases, improvements in irrigation efficiency can increase water consumption because farmers increase the number of irrigated acres or grow more profitable, water-intensive crops. This raises questions about how and where federal funds are allocated, particularly in areas where water shortages are a concern.
The use and significance of irrigated agriculture varies widely across the United States. Although policy discussions related to irrigation typically focus on western states—home to roughly 71% of irrigated farms—irrigation is practiced in all 50 states and is growing in the east. Over time, there has been a shift in water resources used for irrigation, with an increasing reliance on groundwater and less on the use of surface water.
The type of irrigation system used has also shifted over time—from a gravity, or flood-type of irrigation, to potentially more efficient pressurized sprinkler and drip irrigation systems. Pressure systems account for between 58 to 65% of irrigation systems used in the United States and include applicators such as center pivot, surface drip, slide roll or wheel move, and micro sprinkler. Gravity flow, which includes furrow, and controlled and uncontrolled flooding, accounts for approximately 35 to 42% of irrigation systems in the United States. Irrigation BMPs center around how water is managed on a farm and includes on-farm conveyance, irrigation scheduling, and application methods. Increasingly, precision technologies (e.g., drones, sensor networks, data analytics, etc.) are becoming a common part of many irrigation systems because of their potential to increase efficiencies and reduce costs.
The use of irrigation technology and BMPs bring both benefits and costs. The control of water application achieved through irrigation systems can create higher yields and allow the production of higher value crops, while potentially reducing some production costs. The additional cost of installing and maintaining these systems, however, can present a barrier to implementing BMPs. Accounting for variations in the local climate, soil type, water quality, and water availability may also challenge adoption of irrigation technologies and BMPs.