Water conservation has long been an effective component of sustainable water management. However, inelastic price responses, demand hardening, and poor public awareness reduce the effectiveness of strategies. Here, we identify and quantify the effects of psychological and social factors such as attitudes, peer support, opportunities to conserve, and encouragement on household water use. We link household survey, municipal billing, aerial imagery, weather, and appliance flow and duration data. We use the data to develop, populate, and partially validate an agent‐based model for 270 households in Logan, Utah. Simulated indoor water use matched observed use better than outdoor use and improved over prior studies that only conceptually validated model results. Households with stronger conservation attitudes, peer support, and more opportunities saved the most water. Peer pressure saved more water than water manager encouragement because small, diverse social networks could better regulate the behavior of outlier households within the network. Combining peer pressure and encouragement saved the most water. Results suggest managers should provide platforms for households to share their water use stories and information with each other. Managers should target conservation actions to the small fraction of households who use the most water and have large potential to save water. Mangers can use the psychological and social factors to increase household adoption of water conservation actions.