Big Ditch & Big and Long Creek Watershed Implementation Plan

Northwater was retained as the lead consultant to assist the Agricultural Watershed Institute (AWI) in completing an Illinois Environmental Protection Agency (IEPA) funded Watershed Implementation Plan for Big Ditch and Big and Long Creek. The project was unique and challenging due to its short time frame and its high nitrogen loading.  Both watersheds drain to Lake Decatur, a public water supply lake experiencing issues with sedimentation and excessive nutrient loading.  The AWI received a grant to develop two detailed watershed implementation plans.  Northwater was contracted by AWI to complete specific components of the overall plans.

Roles included identifying Best Management Practices in addition to performing advanced GIS analysis and mapping. Northwater built a custom GIS-based pollution load model, identified over 300 site-specific implementation projects and numerous basin-wide practices. Expected pollution load reductions associated with recommended actions were calculated and cost estimates were developed for each project. Northwater also coordinated with the Illinois State Water Survey to utilize a previously completed SWAT model, developed a water quality monitoring plan, identified and mapped critical areas and completed all plan formatting.

The project was completed under a very aggressive schedule.

Project Details
  • Location: Decatur, Illinois
  • Client: Agricultural Watershed Institute
  • Sector: NGO