Zulham Sirajuddin is a doctoral candidate in agricultural education at Iowa State University and a lecturer at Universitas Ichsan Gorontalo, Indonesia. T he drive to protect and improve surface water quality requires an array of policies, institutions, professionals, and procedures, even in the face of uncertain budgets and an increasing scope of work. Since the 1990s, the concept of "citizen science" has provided a framework under which volunteers supplement the water monitoring duties of scientists by producing more data and, in some cases, expanding their reach (Conrad and Hinchey 2011; McKinley et al. 2017). Volunteers, on the whole, benefit by contributing to society (Lawrence 2006), and by learning about science and environmental issues (Hecker et al. 2018; McKinley et al. 2017; Phillips et al. 2018). Many citizen science programs welcome youth, but this paper focuses on programs for adults. Citizen science programs address many types of science, not just water monitoring. Species monitoring contributes to biodiversity conservation (e.g., bird counts, whale watching, and butterfly migration), and space science and astronomy programs have expanded (Dickinson et al. 2012). Water quality monitoring is considered to be one of the largest activities (Conrad and Hinchey 2011), with program numbers in the United States estimated from 1,675 (Stepenuck 2013) to 1,720 (National Water Quality Monitoring Council 2019). Volunteer water monitoring has provided scientists with more data, and from more locations, than originally hoped (Conrad and Hinchey 2011). Data produced by citizen science projects have contributed to science knowledge and to policy development on local, state, regional, and national levels (Dickinson et al. 2012; Lubell et al. 2002; McKinley et al. 2017). BACKGROUND: IOWATER This article reports on an investigation of social engagement impacts of Iowater Volunteer Water Quality Monitoring Program, a citizen science water monitoring program. Iowater was a statewide program administered by the Iowa Department of Natural Resources (IDNR) for more than 20 years, which aimed to (a) involve the