Otter Lake Water Source Protection

Northwater Consulting was retained by the Otter Lake Water Commission to design and implement a long-term program to address water quality regulatory impairments for the lake. The goal of the program is concurrently focused on improving the health of the lake to reduce water treatment costs and enhance the lake’s recreational value. The program has been successful in achieving full support for a public and food processing water supply designated use. As of 2014, aquatic algae and manganese have been delisted as regulatory impairments. The project was recently awarded the prestigious Water Source Protection award by the American Water Works Association (AWWA).

A lake and watershed assessment, modeling and monitoring program identified and quantified sources and causes of the impairments. With this information and coordination with landowners, Northwater developed a detailed multi-phase implementation plan and secured Illinois EPA Section 319 program funding. 2010 and 2013 programs included over seventy BMP projects, which resulted in significant lake delivery reductions of sediment (3,000 tons), phosphorus (3,500 lbs) and nitrogen (8,000 lbs). The BMP projects included numerous water and sediment control basins, sediment basins, ponds, riffle grade-control structures and sediment basin maintenance.

Additional activities led by Northwater have included 175-acres of invasive species removal and 400-acres of prairie restoration. A lake shoreline initiative included mapping of the lake to estimate erosion and develop prioritized stabilization implementation plans. The stabilization of targeted areas in 2010 and 2014 has resulted in significant load reductions in sediment (>10,000 lbs/yr), nitrogen (>15,000 lbs/yr) and phosphorus (>10,000 lbs/yr).

Northwater Consulting has served as the program manager and has provided a complete package of services to support the program.  The project has been entirely implemented and planning for a new phase is currently in progress.

Project Details
  • Location: Macoupin County, Illinois
  • Client: Otter Lake Water Commission
  • Sector: Water Supply