Three community engagement projects on the South Island of New Zealand are enacting education and communication initiatives to improve the uptake of best management practices on farms regarding nutrient management for improving water quality. Understanding the enablers and barriers to effective community-based catchment management is fundamental to planning, implementing and evaluating these initiatives. This article investigates some key predictors of success or determinants of effective community engagement. Six factors were identified: access to science, training, and information; confidence in regulatory policies; leadership; farm planning and monitoring; trust in the public; and concern for water quality.