Inflow/Infiltration Reduction Program – Austin, MN

Inflow/Infiltration Reduction Program


Like many cities in Minnesota, Austin faces a challenge with Inflow and Infiltration (I/I) in its sanitary sewer collection system. During significant rainfall events, the system is overloaded by excess ground water and rain water (clear water). When it rains, flows can jump up to eight times the normal rate. Overloaded sewers lead to basement backups, and in extreme cases, requires bypassing flow directly to the river. This causes damage to homes, personal property, health concerns, and environmental issues.

In 2017, the City of Austin initiated an I/I Reduction Program. To maximize the City’s “bang for their buck”, the first phase of the program includes a comprehensive sump pump inspection program. The City Council adopted the Sump Pump Ordinances in April 2018.

The project is anticipated to be a 5-6 year City-wide, multi-phase program. Work is underway.

Phase 1: Prepared a comprehensive sump pump inspection program. The City Council adopted the Sump Pump Ordinance in April 2018.

Phase 2: WHKS performed televised inspections of sanitary sewer, manhole inspections, smoke testing, and sump pump inspections within the Southwest Central/Fairgrounds sector of the City that consisted of 117,000 L.F. of sanitary sewer mains, 454 manholes, and 2,100 private sewer accounts.

Phase 3: Consisted of sanitary sewer collection system inspections, sump pump/beaver drain inspections, analysis and CIP recommendations within the Southwest Turtle Creek sector of the City.

Phase 4: Currently underway and includes additional investigation methods including additional manhole inspections, dye testing, lateral inspections, and CCTV coordination.


  • Sump pump inspection
  • Manhole inspections
  • CCTV coordination
  • Dye testing
  • Lateral inspections
  • Capital Improvement Planning
  • Sanitary system analysis
  • Public involvement