Agriculture and Water Policy in Imperial Valley, California
A mixed-methods assessment of the Quantification Settlement Agreement
ABOUT ME
My name is Gabriela Morales and I am a NOAA EPP Earth System Sciences and Remote Sensing Scholar in the Department of Geography at San Diego State University (SDSU). My faculty advisor is Dr. Trent Biggs at SDSU and my NOAA mentor is Michelle Stokes at the Colorado Basin River Forecast Center (CBRFC) in Salt Lake City, Utah.
BACKGROUND
Study Area: Imperial Valley, California
The Imperial Valley (IV) is an agricultural region located in Southern California, south of the Salton Sea along the U.S.-Mexico border. The region’s agriculture industry plays an important role in Imperial County, contributing to 25.9% of economic output and providing direct and additional employment for nearly 25,000 workers. Crops in the IV are grown with irrigated water sourced from the Colorado River.
Though the Valley only receives about 3 inches of rain per year, its irrigated agriculture system yields enough to provide the majority of winter crops for the United States. Winter crops include winter melons, lettuce, and table vegetables. The Colorado River is the “lifeblood” of for these winter crops, and the Imperial Valley’s senior water rights to approximately 3.5 million acre-feet of water per year makes it all possible.
The Quantification Settlement Agreement of 2003
The Quantification Settlement Agreement of 2003 (QSA), however, decreased the volume of water being transported to the Imperial Valley (IV) from the Colorado River. With a goal of reducing California’s dependence on imported water, parties at federal, state, and regional levels devised a series of water transfers from the Imperial Irrigation District (IID) to surrounding water districts, most notably San Diego County Water Authority (SDCWA).
To conserve the massive volumes of water for transfer to SDCWA, the QSA offered incentives for farmers to take part in the water-conserving fallowing and on-farm efficiency programs in the IID. The fallowing program offered farmers compensation per acre to fallow portions of their land for 2-3 years at a time. Similarly, the on-farm efficiency program offered payment to farmers for installing more efficient, “water-saving” technologies, such as drip irrigation. Though the fallowing program came to an end in 2017 and the on-farm efficiency program continues in 2020, neither program has been investigated in terms of its regional impact on the Imperial Valley. With the QSA as a backdrop, this study explores the Imperial Valley’s agricultural response to changes in water supply. I will examine physical and human responses to the QSA to illustrate the Valley-wide reaction to QSA policy and programs.
RESEARCH QUESTIONS
RQ1:
How did Valley-wide agricultural production, fallowing, water balance, and water productivity change after the Quantification Settlement Agreement (QSA) was enacted?
RQ2:
How did fallowing and crop patterns differ based on farmer participation in QSA programs? Were fallowing or changes in crops persistent over time, or temporary?
RQ3:
Do changes at the Valley-wide scale match key informant perceptions of water availability and water scarcity in the Imperial Valley?
METHODS
This study uses a "mixed-methods" approach that combines quantitative and qualitative data, methodology, and analysis.
Hydrologic Data Analysis
- I calculated a Valley-wide simple water balance for the years 1995-2018 to represent time before and during QSA implementation. The simple water balance quantifies how much water flows in ("inflow") and out ("outflow") of the Valley.
- Total consumptive water use (TCU), a numerical estimate of how much water has been used within the Imperial Valley, was found by subtracting total annual outflow from total annual inflow from 1995-2018.
Basic Agricultural Economics
- To understand changes in agricultural productivity, I used the TCU as well as crop values from the Imperial County’s annual crop reports to calculate the value of agricultural production for each year (1995-2018).
- Values were adjusted for inflation based on the annual consumer price index for California (CCPI) and normalized to a 2003 base year, which allowed us to compare agricultural production values relative to the year the QSA was implemented.
Remote Sensing and Geographic Information Science
- Images from the United States Department of Agriculture (USDA) were used to estimate total fallowed area by re-assigning pixel values in the “fallow” class a value of 1 while assigning all other classes representing other crop types a value of 0. This process, known as reclassification, allowed me to calculate total fallowed area and see potential clusters of fallowing on an annual time step.
- To show how fallowing and cropping choices changed since QSA enactment, I will create tables called “transition matrices”, which will a) show year-to-year change in the amount of fallowed area in the IV and b) test if there were significant transitions to higher value, lower water-use crop types.
- I will also create maps using ArcGIS Pro to spatially visualize transitions in fallowing and crop type. Maps will use field-level data from the Imperial Irrigation District.
Key Informant Interviews
- Key informants are defined in this study as professional experts who work on issues facing the Imperial Valley, are familiar with the QSA and its fallowing and water conservation programs, and can speak professionally on behalf of a public organization.
- I interviewed three key informants to supplement my quantitative data: (1) a professional expert from the Imperial Irrigation District (IID) working directly with the QSA, (2) a researcher with academic and scientific interest in the Imperial Valley, and (3) a spokesperson for a non-profit group interested in community-level responses to the QSA’s impact.
SOCIAL RELEVANCE
- This research will contribute to evaluating the effectiveness of the Quantification Settlement Agreement while adding to conversations on water management in the Imperial Valley.
- Regional and local stakeholders may also benefit from considering the effects of complex regional policies like the QSA at multiple levels. An exploration of the Quantification Settlement Agreement from multiple disciplinary angles will present stakeholders with vital insight into hydrologic, socioeconomic, and agricultural change from a Valley-wide perspective.
- Furthermore, an investigation of the Imperial Valley’s regional response to changes in water supplies will help prepare us to adapt to changes in water availability that may arise in the future, especially in regions with arid (desert) climates.
RESULTS
- So far, results (see graph above) have indicated that inflow to the Imperial Valley did, in fact, decrease following QSA implementation (red). Despite decreased inflow, annual water productivity in the Imperial Valley increased since the Quantification Settlement Agreement (QSA) took effect (yellow). Additionally, total consumptive water use (TCU) showed a decreasing trend (blue).
- Key informants, however, expressed that decreased inflow to the Imperial Valley was not a major factor in farmer decisions relating to crop choice and fallowing. Rather, according to the key informants, farmer decisions were more economically driven.
NERTO EXPERIENCE
My NOAA Experiential Research & Training Opportunities (NERTO) was completed at the NWS Colorado Basin River Forecast Center (CBRFC) in Salt Lake City, Utah with Michelle Stokes and John Lhotak as my mentors. My project worked with the recently-developed National Water Model (NWM); I investigated the ability of the NWM to represent Evapotranspiration (ET) over a study catchment within the Colorado River Basin. New skills acquired during this internship included working with models and modelling programs, as well as applying hydrologic concepts and principles of watershed analysis to research with real-world implications.
ACKNOWLEDGEMENT
This study is supported and monitored by The National Oceanic and Atmospheric Administration– Cooperative Science Center for Earth System Sciences and Remote Sensing Technologies under the Cooperative Agreement Grant #: NA16SEC4810008. The author would like to thank The City College of New York, NOAA Center for Earth System Sciences and Remote Sensing Technologies, and NOAA Office of Education, Educational Partnership Program for full fellowship support for Gabriela Morales. The statements contained within the Story Map are not the opinions of the funding agency or the U.S. government, but reflect the author’s opinions