Project Overview

Segments of pavement along 15 Mile Road in Sterling Heights, Michigan began to show signs of sinking. Shortly after the road was barricaded, the road sections continued to sink until the road completely fell into a cavernous sinkhole measuring approximately 65 by 200 feet, and with a depth of approximately 50 feet. The cause of the sinkhole appeared to be the failure of an 11-foot diameter sewer, which was constructed in a tunnel in the 1970’s at an approximate depth of 60 feet below ground surface. NTH was contacted by the City of Detroit, Detroit Water and Sewerage Department (DWSD) and requested to quickly mobilize to determine the cause of the failure and to develop plans and specifications to repair the sewer and return the site to pre-sinkhole conditions.

Project Scope

NTH, acting as the lead engineer, divided our services into two tasks. Task 1 included investigation of the failure and preparation of a temporary sewerage flow bypass plan to maintain flow of the 11-foot sewer, which provides discharge for the entire Clinton Township area.

Task 2 of NTH’s services included development of restoration plans for the entire alignment of the project that began approximately ¼ mile east of Hayes, and continued to Moravian located west of Hayes.

Working with the City of Detroit, DWSD, City of Sterling Heights, City of Fraser, Clinton Township, the Michigan Department of Environmental Quality, and the Road Commission of Macomb County, NTH successfully completed the restoration plans to restore the entire alignment.

Client Benefit

The fast-track schedule and the significant pressure, both politically and technically, made this one of the more challenging projects undertaken by NTH.