Patoka Lake is a significant area of natural beauty within the Patoka Lake Watershed located in southwest Indiana. Patoka Lake also serves as the drinking water source for more than 100,000 residents in 12 counties throughout southwest Indiana. Its confluence with the Patoka River lies in the northeastern corner of Dubois County and is where the City of Jasper draws its drinking water from. A mix of farms and agricultural land, small towns, and magnificent geological features mark this watershed that contributes water to Patoka Lake.

     For several years in the EPA Assessment Database, IDEM has listed Patoka Lake as threatened for drinking water use.  This assessment was initially based on the predominance of blue-green algae in summer lake samples, despite the low trophic state of the waterbody overall. This assessment remains today because of the presence of the exotic blue-green algae, Cylindrospermopsis raciborskii. The Army Corps Of Engineers confirmed the presence of Cylindrospermopsis raciborskii in 2001.

     Efforts to address the pollution problems of Patoka Lake began in December 2004 when representatives from the Patoka Lake Regional Water & Sewer District contacted Toby Days with the Alliance of Indiana Rural Water. The two organizations agreed to voluntarily work within the community to develop a Source Water Protection Plan (SWP) for the Patoka Lake Watershed and support implementation of voluntary best management practices (BMPs) in the watershed. As this progressed through the spring and summer of 2005, a draft SWP plan was developed for the Patoka Lake Watershed and several public meetings were held together input from other Patoka Lake Watershed stakeholders regarding perceived problems, goals, and activities that need to be addressed. 

     Community and State based support for the Source Water Protection Plan for the Patoka Lake Watershed led the Alliance of Indiana Rural Water and the Patoka Lake Regional Water & Sewer District to seek out a mechanism to support such a voluntary, community-based, and community-led watershed management plan. In October of 2005, a CWA Section 319 grant application, sponsored by the Patoka Lake Regional Water & Sewer District, was submitted to IDEM to support the implementation of the Source Water Protection Plan for the Patoka Lake Watershed.

     The Source Water Protection Plan for the Patoka Lake Watershed is intended to be a living document designed to assist the watershed stakeholders in their efforts toward the restoration and protection of the Patoka Lake Watershed.