Water withdrawals for human use can reduce water in lakes and streams, with significant consequences for aquatic biota. Urbanization, particularly large lawn areas associated with low-density residential development, increases demand on freshwater resources. Outdoor water use accounts for the largest proportion of residential water use during the summer months, which corresponds to the lowest water levels in freshwater ecosystems. Prior studies have sought to understand property features associated with the highest water use; however, these studies do not consider other types of water use nor do they capture the decisions by residents that result in outdoor water use. Understanding these decisions is critical for developing policies and education tools that reduce outdoor water use by changing people’s water use behavior. Focusing on the Ipswich River Watershed, which has been impacted by extreme low flows due to water withdrawals, a mixed-methods approach was used to understand residents’ outdoor water use and the factors influencing the amount and timing of water use. To quantify water use meters were placed on outdoor spigots at residences, participants were provided with a written survey before and after water metering, and in-person interviews were conducted. Irrigation systems used the most water; however, garden watering occurred as frequently as lawn irrigation and many participants indicated that their garden was a primary factor in water use decisions. Participants’ water use decisions fell into categories from habitual (i.e., watering at the same time of day) to purely cognitive (i.e., watering based on weather and plant needs). While many participants felt that water conservation was necessary, their willingness to implement landscape-level conservation practices, such as rain barrels, did not differ from participants who believed water conservation was unnecessary. Interestingly, many residents reduced their outdoor water use behavior and increased their concern for other environmental issues in response to study participation. To have the greatest impact on overall water use, efforts should focus on residents running irrigation systems on a schedule. Outreach should emphasize individualized approaches to water conservation, regardless of water source (public or private), and include information and conservation options specific to the water needs of the individual property.