Implementation of Best Management Practices to Reduce Agricultural Total Maximum Daily Loads in the Calleguas Creek and Santa Clara River Watersheds: A Case Study of Water Contaminant Mitigation in California

Abstract

<jats:p>Agriculture is a major industry in California, with cool-season crops grown along the state’s coasts, warm-season crops grown in the hot deserts, and many temperate crops grown in the state’s valleys. In coastal communities such as Ventura County, the Calleguas Creek and the Santa Clara River watersheds have 50,000 and 60,000 irrigated acres of farm crops, respectively. These watersheds are considered impaired by nutrients, salts, pesticides, and other agricultural contaminants. Mitigation of chemical and sediment runoff through grower-implemented best management practices (BMPs) is therefore one of the highest priorities in the Los Angeles Regional Water Quality Control Board Basin Plan. A 3-year project was designed to assist Ventura County growers in meeting regional water quality objectives. The University of California Cooperative Extension Ventura County and the University of California, Riverside, collaborated with the Ventura County Resource Conservation District and the Ventura County Agricultural Irrigated Lands Group (VCAILG) to address three project goals: increase grower and landowner understanding of local agricultural water quality issues; identify gaps or deficiencies in current management practices in agricultural operations; and reduce the contribution of nutrients, pesticides, and other pollutants to impaired water bodies. To achieve these goals, 469 surveys of agricultural water quality management practices were collected to assess the extent of current adoption of BMPs. Over 160 growers who farm more than 14,000 acres that drain into Calleguas Creek and 7,000 acres that drain into the Santa Clara River watersheds were assisted. Using the survey, growers developed site-specific farm water quality plans and received on-farm recommendations for BMPs. Additionally, 12 water quality educational programs, “including demonstrations of successful BMPs,” were developed and more than 2500 copies of educational materials published by the University of California, the Resource Conservation District, and the Natural Resources Conservation Service of the U.S. Department of Agriculture were distributed at on-farm visits, workshops, and other grower events. The project resulted in improved understanding, by growers and landowners, of water quality issues and significantly increased the implementation of appropriate on-farm BMPs to protect water quality. Nearly 100 new BMPs primarily aimed at managing erosion, sediment movement, and irrigation runoff were identified and documented through annual reassessments for more than 8000 acres draining into Calleguas Creek. A total of 518 people attended the educational programs, and over 90% of participants who completed evaluations rated the programs highly. In the final year of the project, 75% of attendees indicated they plan to implement new BMPs within the next 5 years, especially in the areas of irrigation, erosion, and pest management.</jats:p>

Selecting methods of agricultural extension to support diverse adoption pathways: a review and case studies

“…The importance of farmer involvement in establishing BMPs has also been highlighted in contexts including BMPs to deal with climate risks (George et al 2019) and water quality (Merhaut et al 2013). Farmer involvement in developing the guidelines and how they were communicated increased trust by farmers and ensured that BMP guides contained practical inputs concerning business and operational issues along with science.…”

“…Farmer involvement in developing the guidelines and how they were communicated increased trust by farmers and ensured that BMP guides contained practical inputs concerning business and operational issues along with science. Additional methods such as on-site visits and direct on-farm recommendations increased understanding of issues and significantly increased the implementation of appropriate BMPs (Merhaut et al 2013) as did meetings with advisers, attendance at seminars (Rahelizatovo and Gillespie 2004) and involvement in demonstrations and field-scale projects with 'model growers' where multiple practices integrated into whole-farm management are displayed (Hopkins et al 2007). The role of farm data in farmer learning and monitoring and tracking progress toward BMPs has also been identified as an emerging consideration in the design of BMP programs (Turner and Irvine 2017;Sumner et al 2018).…”

Regulating Water Quality: Current Legislation, Future Impacts: Introduction to the Colloquium

“…Agricultural producers can maintain a presumption of compliance with these approved numeric criteria by enrolling in the Florida Department of Agriculture and Consumer Services Best Management Practices (BMPs) Program and by implementing approved BMPs (Florida Department of Agriculture and Consumer Services Office of Agricultural Water Policy, 2011). Merhaut et al (2013) discuss the current regulations and the educational programs that were used to help the agricultural sector mitigate nutrient and pesticide runoff in specific watersheds in southern California and the monitoring protocols that were used to measure changes in runoff water quality in these particular watersheds. They focused on specific educational programs that have been developed to educate growers about BMPs that mitigate pesticide and nutrient runoff from specific production sites and the monitoring protocols used to verify the efficacy of grower adoption of BMP practices.…”

Choosing Nitrogen Application Rate Recommendation Given Florida’s Regulatory Water Policy

“…§1329(a)(1)(C)]. While program design varies among the states (Majsztrilk and Lea-Cox, 2013;Merhaut et al, 2013), most states rely on voluntary policies supported by cost-share programs. A few states (e.g., Maine, North Carolina, Maryland, and Pennsylvania), however, employ a regulatory approach that specifies agricultural practices to be used, such as bans on manure and fertilizer applications, setback standards on river banks, or required BMP program participation (Baerenklau et al, 2016;Kling, 2013).…”