2024 Annual Multibenefit Land Repurposing Program Report

California Department of Conservation (CDoC) | May 29th, 2025

The Multibenefit Land Repurposing Program (MLRP) increases regional capacity for repurposing irrigated agricultural land to uses that reduce reliance on groundwater while

The Multibenefit Land Repurposing Program (MLRP) increases regional capacity for repurposing irrigated agricultural land to uses that reduce reliance on groundwater while providing community health, economic well-being, water supply, habitat, renewable energy, and climate benefits. The program provides funding for regional block grants, tribal grants, and a Statewide Support Entity to provide technical assistance to block grantees and support progress toward program goals.

2025 Agricultural Water Management Plan Guidebook

California Department of Water Resources (DWR) | September 30th, 2025

Agricultural water suppliers in California have a long history of preparing agricultural water management plans (AWMPs) and implementing efficient water management practi

Agricultural water suppliers in California have a long history of preparing agricultural water management plans (AWMPs) and implementing efficient water management practices (EWMPs).  However, water management planning is not static; changing conditions and understanding of the system necessitate revisiting, adapting, and improving planning and implementation efforts. The five-year cycle AWMP is an opportunity for individual agricultural water suppliers to closely examine their practices and systems to find areas where operations can be improved and where water can be used more efficiently. An AWMP can also provide information and a record to the public on the agricultural water supplier’s stewardship of our limited water resources.

2025 Agricultural Water Management Plan Guidebook (Draft)

California Department of Water Resources (DWR) | July 23rd, 2025

The 2025 Agricultural Water Management Plan Guidebook (Guidebook) was prepared by DWR to assist agricultural water suppliers in understanding and complying with the requi

The 2025 Agricultural Water Management Plan Guidebook (Guidebook) was prepared by DWR to assist agricultural water suppliers in understanding and complying with the requirements of the Agricultural Water Management Planning Act (Division 6, Part 2.8 of the California Water Code), the Agricultural Water Measurement Regulation (Title 23, Division 2, Chapter 5.1, Article 2 of the California Code of Regulations), and AB 1668 Water Management Planning (Friedman, Statute of 2018). This Guidebook is intended to clearly identify information and elements required by the California Water Code (Water Code), provide guidance on how Agricultural Water Suppliers can address these requirements, and identify potential additional information Agricultural Water Suppliers can include in order to develop plans that are useful for their own operations and management and to improve long-term system reliability. This Guidebook also describes how Water Conservation Plans (WCPs) submitted to the United States Bureau of Reclamation (USBR), and Urban Water Management Plans (UWMPs) submitted to DWR, can be supplemented to satisfy the Water Code and Agricultural Water Measurement Regulation requirements.

A Bayesian approach to infer nitrogen loading rates from crop and land-use types surrounding private wells in the Central Valley, California

European Geosciences Union (EGU) | May 7th, 2018

This study is focused on nitrogen loading from a wide variety of crop and land-use types in the Central Valley, California, USA, an intensively farmed region with high�

This study is focused on nitrogen loading from a wide variety of crop and land-use types in the Central Valley, California, USA, an intensively farmed region with high agricultural crop diversity. Nitrogen loading rates for several crop types have been measured based on field-scale experiments, and recent research has calculated nitrogen loading rates for crops throughout the Central Valley based on a mass balance approach. However, research is lacking to infer nitrogen loading rates for the broad diversity of crop and land use types directly from groundwater nitrate measurements. Relating groundwater nitrate measurements to specific crops must account for the uncertainty about and multiplicity in contributing crops (and other land uses) to individual well measurements, and for the variability of nitrogen loading within farms and from farm to farm for the same crop type. In this study, we developed a Bayesian regression model that allowed us to estimate land-use-specific groundwater nitrogen loading rate probability distributions for 15 crop and land-use groups based on a database of recent nitrate measurements from 2149 private wells in the Central Valley. The water and natural, rice, and alfalfa and pasture groups had the lowest median estimated nitrogen loading rates, each with a median estimate below 5 kg N ha -1 yr -1. Confined animal feeding operations (dairies) and citrus and subtropical crops had the greatest median estimated nitrogen loading rates at approximately 269 and 65 kg N ha -1 yr-1, respectively. In general, our probability-based estimates compare favorably with previous direct measurements and with mass-balance-based estimates of nitrogen loading. Nitrogen mass-balance-based estimates are larger than our groundwater nitrate derived estimates for manured and non-manured forage, nuts, cotton, tree fruit, and rice crops. These discrepancies are thought to be due to groundwater age mixing, dilution from infiltrating river water, or denitrification between the time when nitrogen leaves the root zone (point of reference for mass-balance derived loading) and the time and location of groundwater measurement.

A Benchmark Dataset of Agricultural Weather Stations over the Contiguous United States for Evapotranspiration Applications

Nature Portfolio (Springer Nature) | August 12th, 2026

Agricultural weather data are fundamental for the accurate estimate of evapotranspiration (ET), irrigation scheduling, and water-use accounting. In particular, reference

Agricultural weather data are fundamental for the accurate estimate of evapotranspiration (ET), irrigation scheduling, and water-use accounting. In particular, reference ET provides a standardized atmospheric demand for water loss from a hypothetical well-watered grass (ETo) or alfalfa (ETr); however, weather stations may not adequately represent such climatic conditions. Weather data commonly contain errors from poor siting, sensor drift, and network management deficiencies. No standardized dataset exists over the contiguous United States (CONUS). Systematic errors affect ETo/ETr calculations and derived products. Notably, satellite-based platforms like OpenET require agricultural weather data to bias correct gridded reference ET to interpolate between satellite overpasses. CONUS-AgWeather is a benchmark dataset of daily agricultural weather data (precipitation, solar radiation, air temperature, humidity, wind speed, ETo, ETr) from 793 stations. This dataset contains 4,191,808 days (11,484 station-years, 1981–2020) and was produced through standardized and systematic quality control procedures and open-source software packages for time series inspection, outlier detection, corrections, and ETo/ETr calculations. CONUS-AgWeather is intended primarily to support OpenET in the Western U.S. but has broader applications.

A case study of canal seepage quantification using gain/loss method and electrical resistivity tomography in an intensively managed water resource system in the Treasure Valley, Idaho, United States

Elsevier | November 12th, 2024

Monitoring groundwater-surface water (GW-SW) interactions is essential for effectively managing the available water resources in semi-arid and arid environments. The focu

Monitoring groundwater-surface water (GW-SW) interactions is essential for effectively managing the available water resources in semi-arid and arid environments. The focus of this study was to quantify how much SW is being exchanged with the shallow GW aquifer in the Treasure Valley (TV), Idaho, USA. Previous water budgets estimated regional canal seepage without incorporating canal variability and flow measurement uncertainty. To address this, we applied both direct (gain/loss) and indirect (electrical resistivity tomography (ERT)) techniques. Direct seepage measurements were taken on canals capturing a range of different characteristics in the TV. The discrete measurements were then used to estimate the total seepage anticipated to be lost from these canals during the irrigation season. Our findings showed high seepage variability across the canals. The ERT inversion approach was utilized before and after the irrigation season by applying an advanced inversion scheme to better constrain the canal seepage spatial variability and uncertainty by quantifying changes in the saturated zone with 2D-ERT results. Temporal changes in the subsurface resistivity were observed due to the lateral flow from the nearby surface canal during the irrigation season. The combination of these approaches improves our understanding of SW-GW interactions in intensively managed irrigation systems.

A Comparative Study for Estimating Crop Evapotranspiration in the Sacramento-San Joaquin Delta

University of California, Davis (UC Davis) | April 23rd, 2018

Consumptive water use by crops, often referred to as evapotranspiration (ET), is frequently the largest component of an agricultural region’s water balance. This study

Consumptive water use by crops, often referred to as evapotranspiration (ET), is frequently the largest component of an agricultural region’s water balance. This study investigates crop consumptive use in the Sacramento-San Joaquin Delta (“Delta”) of California using a comparative approach with several prominent methods for estimating crop ET, including estimates based on crop coefficients, water balances, energy balance using remote sensing, and field measurements. Click here to download full report and links to appendices

A Conservation Footprint for California Rice

California Rice Commission (CRC) | January 31st, 2025

Rice agriculture, especially winter-flooded rice fields, provides surrogate wetlands that host a diversity of species in the Central Valley. Rice fields are critical for

Rice agriculture, especially winter-flooded rice fields, provides surrogate wetlands that host a diversity of species in the Central Valley. Rice fields are critical for Giant Gartersnakes, wintering waterfowl, wintering and breeding shorebirds, Sandhill Cranes, native fishes, and many other species. However, uncertainties in climate, water availability, agricultural crop markets, and urban expansion are precipitating changes in management practices increased variability and magnitude of fallowing, and, in some cases, crop conversion. 

A global spatial analysis reveals where marine aquaculture can benefit nature and people

PLOS | October 9th, 2019

Aquaculture of bivalve shellfish and seaweed represents a global opportunity to simultaneously advance coastal ecosystem recovery and provide substantive benefits to hum

Aquaculture of bivalve shellfish and seaweed represents a global opportunity to simultaneously advance coastal ecosystem recovery and provide substantive benefits to humanity. To identify marine ecoregions with the greatest potential for development of shellfish and seaweed aquaculture to meet this opportunity, we conducted a global spatial analysis using key environmental (e.g., nutrient pollution status), socioeconomic (e.g., governance quality), and human health factors (e.g., wastewater treatment prevalence). We identify a substantial opportunity for strategic sector development, with the highest opportunity marine ecoregions for shellfish aquaculture centered on Oceania, North America, and portions of Asia, and the highest opportunity for seaweed aquaculture distributed throughout Europe, Asia, Oceania, and North and South America. This study provides insights into specific areas where governments, international development organizations, and investors should prioritize new efforts to drive changes in public policy, capacity-building, and business planning to realize the ecosystem and societal benefits of shellfish and seaweed aquaculture.

A greener grass: Can the environmental impact of cannabis cultivation be reduced?

Nature Portfolio (Springer Nature) | August 28th, 2019