[brcs-announce] Brownbridge Dam Update From Steve Largent

[Norman R. Fred]

Thursday (9-6-12) – The Labor Day 
holiday weekend brought a large number of people to the Brown Bridge 
Quiet Area to view first-hand the removal of Brown Bridge Dam and the 
restoration of the original river channel through the east end delta 
area.  For the most part everyone viewed the progress from the 
designated viewing areas but a few people wandered into the construction area for a closer look.   When encountered these folks were politely 
asked to please stay on designated trails and viewing areas.  No major 
issues were reported.  AMEC and Molon commenced again early Tuesday 
morning.  They continued to install the temporary dewatering structure 
using a larger driver.  This worked to a degree but Molon is planning to bring in an even larger driver later this week.   Most of the sheet 
piling is with a few feet of their target depth.  Late last week 
Beirlien completed phase-I demolition of the power house with the 
removal of the south bay turbine.  The head-gate is used to control the 
pond level which is holding steady at 789.0.  As you can see from the 
attached picture of the south bay turbine wicket gates zebra mussel had 
pretty much encrusted the gates.  The north bay turbine wicket gates are in the same condition.  Molon welded a rod to an arm that operates the 
gates yesterday and used an excavator to move the lever and open the 
wickets gates to pass water through the north bay.  It worked and they 
used the same process to close the gates again.
 
As last reported, Molon brought in a much larger excavator and as of 
yesterday they had dredged close to 45,000 cubic yards.  Everything is 
going well and have actually opened part of the new river channel to 
flow.  There’s some question about how to handle some really fine 
sediment under the East Overlook.  Project engineers and managers from 
AMEC, Inter-Fluve, and Molon are currently determining the best course 
of action to dredge the new river channel in this location.  Overall 
everything is proceeding very well.  Please let me know if you have any 
questions.  S.
 
 Steve Largent
Boardman River Program Coordinator
Grand Traverse Conservation District
231.941.0960 Ext - 16
231.883.9960
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