An NPDES permit is valid for a maximum of five years. If the applicant continues to require NPDES permit coverage, it is necessary to reapply by April 1 of the year the permit will expire. This generally involves completing a new application form. This gives the Water Bureau an opportunity to reevaluate operational and monitoring requirements and effluent limits.

Michigan has developed a strategy for scheduling permit reissuance known as the "5-Year Basin Plan." This is a timetable for reissuance of permits based on receiving water-bodies. A receiving water is the river, stream or lake that "receives" a particular discharge. It is ideal to simultaneously evaluate all permits allowing discharge to a particular receiving water or watershed. A complete cycle of reissuances occurs every 5 years, with approximately 20% of the permits being reissued each year. The "5-Year Basin Plan" was established with the objective of establishing the most efficient plan for water quality monitoring and permit reissuance.

Maps of the various watershed basins may viewed by clicking on the links below.

• Watershed Evaluation Schedule

• Cycle Year 1 Watersheds

• Cycle Year 2 Watersheds

• Cycle Year 3 Watersheds

• Cycle Year 4 Watersheds

• Cycle Year 5 Watersheds