This research explores Ontario's Clean Water Act (S. O. 2006, c. 22) and its contribution to capacity building for rural municipalities impacted by source protection plans created under the Act. Source water protection (SWP) under the Clean Water Act (S. O. 2006, c. 22) is explored drawing from a capacity framework. A nested case study approach has been employed to allow for in depth exploration of the experience within the Cataraqui Source Protection Area and the North Bay-Mattawa Source Protection Area, where key informant interviews were conducted. Findings are outlined looking at four elements of capacity for SWP: institutional, financial, social, and technical/human. It was found that the process was successful for building capacity in the serviced rural municipalities involved, but did not provide any meaningful protection for areas reliant on private drinking water systems such as wells. Several improvements to the legislated process were suggested including greater flexibility for local circumstance and better methods for engagement of First Nations and the general public. It is unknown if this capacity will be sustained as the program continues and provincial funding is reduced. Reduced funding will particularly impact rural communities that lack the internal human and financial capacity to implement SWP policies without the assistance of provincial funding and conservation authority staff (who also rely on provincial/municipal funding sources). Ultimately, it was found that SWP in rural areas requires enforceable mandatory legislation; sustainable provincial funding and municipal fiscal frameworks to support ongoing SWP planning and implementation; technical aid at the regional level; and support and commitment to SWP at the local level (e.g., municipalities, local health units, landowners, residents and watershed users).