Sewerage District crews document overflows

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MADISON, WIS. – Madison Metropolitan Sewerage District crews have documented six sanitary overflow locations in Madison and neighboring communities following the record-breaking storm overnight Monday.

Stormwater flooding throughout the area contributed to the sanitary overflows. Although the District’s regional wastewater collection system operates separately from municipal stormwater sewers, heavy rains infiltrate the wastewater system through multiple paths including basement floor drains when stormwater enters basements.

Working in coordination with crews from the City of Madison, City of Middleton and the District’s other customer communities, the following sanitary overflows have been documented:

  • Three manholes near Waite Circle and Chippewa Drive in the Nakoma area.
  • Two manholes near Indian Hills Park on the near West side.
  • A manhole near Spoke and Sprocket drives along the Cannonball Path in the City of Fitchburg.
  • A manhole on John Q. Hammons Drive near the Madison Marriott West in the City of Middleton.
  • A manhole near Locust Drive and Rose Place in the Village of Shorewood Hills
  • A manhole near Glenway and Monroe streets, in the UW–Madison Arboretum near Arbor Drive.

District crews have placed berms to contain any residual water and are in the process of cleaning up debris and spreading lime as a health precaution. The District encourages residents to report missing manhole covers, water flowing across roads and water entering homes through sanitary connections. Residents are encouraged to direct their initial contact to their local municipality or sanitary District, which allows crews to coordinate for a timely response. A list of community contacts can be found at

In general, residents experiencing flooding including basements backups should:

  • Treat all floodwaters as contaminated.
  • Be aware of the risk of electrocution. Do not touch electrical equipment if it is wet or if you are standing in water. If it is safe to do so, turn off the electricity to prevent electric shock.
  • Avoid wading in floodwater, which can contain dangerous debris and be contaminated.

By late Tuesday, flows at the District’s Nine Springs Wastewater Treatment Plant had been reduced to a rate of 100 million gallons per day, down from a recorded peak flow rate of 155 million gallons per day. The District typically handles an average daily flow of 42 million gallons. More than two dozen District crew members worked throughout the day to inspect and monitor the more than 141 miles of District- owned pipe.

Overnight Monday, the District’s 18 major pumping stations performed as intended to handle the extreme weather. However, as water continued to enter the system through the morning Tuesday, the volume in some areas of the system exceeded capacity and overflows occurred.

“We appreciate the notifications from community members as it has allowed us to reach and inspect priority areas,” said Michael Mucha, the District’s chief engineer and director. “We continue to work in partnership with our customer communities in addressing the challenges associated with the flooding.”

District staff members have notified the Wisconsin Department of Natural Resources and Public Health Madison and Dane County. For more information about Madison Metropolitan Sewerage District’s regional collection system and the Nine Springs Wastewater Treatment Plant, visit