Growing evidence of agricultural water pollution in California's Central Coast even after the implementation of tough water quality regulations has increased the pressure on regional stakeholders. Previous research has shown that collaborative relationships between growers and regulators can motivate growers to make management decisions that benefit the environment. However, informal evidence suggested trust might have been eroding between growers and the Central Coast Regional Water Quality Control Board (CCRWQCB, the regulator) since 2004, the year the first legislation went into effect. Using a survey conducted in 2015, interviews and in-depth document review, this study assesses growers' trust of and communication with other agricultural groups and water quality regulatory agencies, specifically CCRWQCB. Survey results were compared to results of the same survey sent out in 2006. Results corroborate other research — growers' trust of most regional agricultural groups was closely correlated with frequency of communication. However, growers' trust of CCRWQCB did not correspond to the relatively high contact frequency and had declined since 2006. The literature on rebuilding trust suggests ways forward for CCRWQCB.

Much of modern-day agriculture relies heavily on fertilizers and pesticides to increase yields, yet when applied in excess or without proper control mechanisms these inputs can wreak havoc on local waterways. This dissertation analyzes policy approaches implemented in Europe, the U.S. and California to abate discharges from farms. The research utilizes a mixed methods approach, integrating qualitative, quantitative and spatial analyses, to investigate regulatory tools, governance structures, policy outcomes, and stakeholder opinions relating to water pollution from agriculture. The dissertation is comprised of four interrelated parts. The first part assesses the range of regulatory approaches employed to control agricultural nonpoint source pollution in the United States and the European Union. Findings suggest that transitioning from the voluntary control mechanisms to more effective instruments based on measurable water quality performance relies predominantly on three factors: (1) more robust quality monitoring data and models; (2) local participation; and (3) political will. Identifying obstacles to and successes of national and international agricultural water pollution policies set the context for delving deeper into this regulatory problem on a regional level. The second, third, and fourth parts of this doctoral research focus on the primary regulatory mechanism for agricultural discharges in California’s Central Coast Region: The Conditional Agricultural Waiver. One of these parts uses the policy tool framework to assess the overall effectiveness of the Conditional Agricultural Waiver and its associated monitoring programs. Research results show that while the regional policy represented a small step forward in implementing appropriate control mechanisms for agricultural pollution, the significance of monitoring programs greatly limited the policy’s success. Another part of this dissertation surveyed 1,000 growers and their opinions on water quality practices and regulations. Results corroborate with prior research—growers’ trust in the majority of regional agricultural groups was closely correlated with communication. However, trust in the Regional Board did not correspond to the relatively high contact frequency with the regulatory agency, most likely due to a divergence of interests and institutional distance. This study also confirms anecdotes of declining trust between farmers and the Regional Board over the course of the two Ag Waivers. A final part of the dissertation focuses on specific provisions aimed at controlling two pesticides in the region. Results from this chapter indicate that the 2012 Central Coast Conditional Agricultural Waiver was a contributing factor in successfully reducing the use of diazinon and chlorpyrifos, but several unintended consequences, such as continued presence of the pollutants in waterways, remain unsettled.