Southside Interceptor Sanitary Diversion Project

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UPDATE Sept., 2020:

Work on the project continues. Fuller Street between Glen Court and the Fuller Road/Fuller Street/Glen Avenue Intersection remains closed. 

The Contractor has completed constructing the cast-in-place concrete junction chamber.  The roadway repairs are now well underway.  The new curb and gutter will be placed on Thursday, September 17, 2020.  Roadway paving is expected to occur during the week of September 21st.  Also, the Contractor is coordinating the abandonment of portions of the existing sanitary sewers in the area that are no longer needed due to the construction of the junction chamber.

Public Works staff will also be cleaning a section of the major trunkline sanitary sewer immediately downstream of the project in order to remove existing debris that was discovered during the construction of the junction chamber.  It is best to perform this cleaning now in order to avoid future roadway lanes closures.

Based on the remaining work, we expect the project will be substantially completed and Fuller Street re-opened to traffic on, or about, October 5, 2020 (weather permitting.)

It may be necessary to utilize day time lane closures along Fuller Street while the final clean-up and restoration activities are completed.  We will provide additional information regarding this issue as the work is closer to being completed.​​

​Project limits

Fuller Street between Glen Court and the Fuller Road/Glen Avenue/Fuller Street intersection.


Start of Construction:     May 6, 2020

Expected Completion of Construction (Roadway Re-opened to Traffic):  October 5, 2020

Final Project Completion:  October 9, 2020 (final clean-up and punch list activities)​

​Why is this project being done

This project is being undertaken to divert excess sanitary sewer flow from the Southside Interceptor Sanitary Sewer (the major trunkline sewer that services a large portion of downtown and the westerly side of Ann Arbor) into the Northside Interceptor Sanitary Sewer. The diversion of the excess flow will eliminate sanitary sewer overflows during heavy rain events and reduce environmental damage from the overflows.

Work to be done​

The project will construct a 14' long x 12' wide x 12' tall, cast-in-place concrete, underground chamber that will divert excess flows by the use of a weir within the chamber.  The weir will be adjustable in order to accommodate future changes in sanitary flow patterns in the upstream sanitary sewer. The top of the underground chamber will be about 12' deep and its bottom will about 25' deep.  In order to construct this chamber, it will be necessary to excavate an extremely large hole within Fuller Street and the slope leading down to the railroad right-of-way.  As part of the work, it will also be necessary to relocate a portion of an existing 12" water main and a 24" diameter sanitary sub-main in the vicinity of the diversion chamber. 

Possible Impacts to residents​

Due to the nature of the construction and the needed location of the diversion chamber, it is not possible to maintain through traffic along Fuller Street during the work, therefore a deto​ur (PDF) will be in place. However, access to the U of M Parking Structure, as well as the residential housing units along Glen Court will be maintained to Fuller Street.  Glen Court traffic will be able to enter and exit from west of the project area.

Pedestrian traffic along the southerly side of Fuller Street will be maintained at all times. Access along Depot Street will be maintained to all local area businesses, Wheeler Park, and the Amtrak Station.

A detour route for Fuller Street traffic will be utilized as shown on the attached drawing. The project will also utilize portable, changeable, message signs to provide additional information and way-finding assistance to users of the area.

Information regarding the project has been communicated with Michigan Medicine representatives, emergency responders, and AAATA.  We are working with them to help minimize impacts and delays due to the Fuller Street closure.

This project will generate dust, noise, and inconvenience.  We apologize in advance for this unavoidable impact, but we will take all practicable steps in order to minimize these issues.

Costs and Funding Sources

The total cost of the project is expected to be about $1,734,000 and is being funded from Developer Offset Mitigation funds. 



​Michael Nearing
734.794.6410 ext. 43635 
Larcom City Hall
301 E. Huron St., Fourth Floor
Ann Arbor​, MI 48104​