Technology transfer is a common mechanism for development agencies and nongovernmental organizations to meet their goals of increasing economic productivity, enhancing social capital, and minimizing the impact on the environment in rural areas of Third World countries. The objective of this article was to discuss the hydrological and social impacts of technology transfer in the community of Chilascó, Guatemala. Several technologies were adopted since the 1980s in the region surrounding Chilascó, including technologies related to hydroelectricity, rural electrification, irrigation, and broccoli production. These technology transfers had a direct and indirect impact on the hydrology of the region as streams were diverted, forests were removed, and agricultural fields expanded. Hydroelectricity and irrigation projects have increased demand for water resources at the expense of a community-based ecotourism project in Chilascó. Stream discharge has changed as cloud forests are replaced with broccoli fields. Additionally, these technology transfers had social impacts in the community of Chilascó. Broccoli production is more labor and capital intensive than traditional subsistence agriculture. Social networks have changed as time and labor constraints limit participation in community-level projects. Holistic approaches are necessary to understand the connections between technology transfer, water resources, and social capital before and after the initiation of rural development projects.