Brown Bridge Dam Update

As a follow up to our October 7, 2012 post Reclaiming the Boardman River – Easy? “No” – Worth it? “Yes”, an update on the Brown Bridge Dam project has been released by Conservation Resource Alliance and The Boardman River Dams Implementation Team. 

A summary of the release follows, and the entire document can be retrieved here: Brown Bridge Update

“The Brown Bridge dam removal project is proceeding and is on track to be completed on the original schedule, while team members simultaneously complete assessments of the water release incident that occurred on October 6.  We are particularly grateful to members of the professional and construction team for their rapid and thorough follow up to the incident, and to the investigation and response teams from Michigan DEQ.  All involved are committed to learning from the Brown Bridge project to inform future dam removals throughout the region.”

OCTOBER 6 INCIDENT

At approximately 10:00 a.m. on October 6, an abrupt release of water occurred in the area of the TDS. This abrupt release of water caused varying damage to approximately 50 riverfront properties. The project team immediately worked with property owners to assist with damage mitigation.

AMEC has provided financial assistance to the downstream impacted property owners by paying contractors to perform preliminary cleanup and restoration. AMEC, through its insurance company, has sent adjusters to prepare damage assessments. AMEC also

provided hotel accommodations to property owners who were unable to stay in their homes. AMEC’s project team and insurance adjusters visited over 130 residences door-to-door and assisted over 80 residents who notified the hotline established by the Emergency Management Coordinator. AMEC’s insurance company is maintaining a database system to track and record the list of impacted properties and monitor restoration activities.

INCIDENT INVESTIGATION

An engineering investigation to understand the cause of the October 6 release of water is being conducted by MDEQ’s Dam Safety unit. It is anticipated that the investigation will be completed when the powerhouse is removed and the river channel is constructed in the location of the former powerhouse. The powerhouse is expected to be removed by November 10 and the investigation could be completed within six weeks following powerhouse removal.

Currently, the project team is inspecting the portions of the TDS that can be observed at grade level. The investigation will continue as the project progresses. The cause of the release cannot be determined until the investigation is complete.

STATUS OF BROWN BRIDGE DAM REMOVAL

A few days following the October 6 incident, work resumed in the upper end of the former pond area – cleaning out sand traps, excavating the floodplain, and shaping spoil areas according to the original work plan. At the dam, the project team received work plan approval from the DEQ to divert the river flow into the TDS and continue demolition of the remaining lower concrete structure of the dam. This work began the week of October 29 and is expected to take approximately two weeks to complete. The project team expects to complete the dam removal by its original target date of mid-late December of 2012. As originally planned, certain follow up grading and vegetation work will follow in the spring of 2013.