Santa Clara River Watershed Agricultural Irrigation Thresholds/TMDL

NewFields was contracted by the Los Angeles County Sanitation Districts to serve as the lead technical consultant for the Santa Clara River Watershed TMDL Collaborative Process. NewFields specifically focused on the agricultural irrigation thresholds for chloride and salinity for the production of avocados, strawberries and nursery crops. This work involved collaboration in stakeholder meetings with representatives from:

• California Avocado Commission
• California Strawberry Commission
• Nursery Crop Organizations
• Individual Growers
• Ventura County Farm Bureau
• California Regional Water Quality Control Board
• Newhall Land and Ranch Company
• United Water Conservation District
• Elected Public Officials
• Various Environmental Groups

Over a 2.5-year period, a detailed literature review and evaluation was conducted to determine the potential threshold of irrigation water quality constituents of concern, specifically chloride and salinity, on sensitive crops as a basis of the TMDL process. Local grower input was gathered through interviews and field surveys. To establish acceptable irrigation water quality, NewFields conducted a detailed assessment of water quality, irrigation practices, cultural practices and drainage management. The work also included comprehensive public notification efforts with stakeholder groups, public officials, researchers, and farm managers. A 6-person academic technical panel comprised of experts in this field reviewed all work produced by NewFields. This work has been highly influential in establishing a chloride TMDL for irrigation of sensitive species in the Santa Clara River Basin. Despite the controversial subject matter, the literature review and findings were commended by industry professionals, agencies, environmentalists, and academics on both sides for scientific merit and objectivity.