Transcript The Future of Wixom Lake

“We’re all in this together”
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The dams at Sanford, Edenville, Smallwood
and Secord were built by Frank Wixom in
1925
◦ Wixom owned all the upstream lands that were
flooded
◦ The flooding created four reservoirs and lots of
waterfront real estate
◦ Hydroelectric power was a relatively new industry
and in its heyday in the 1920s
◦ Dams provide recreational opportunities and flood
control that would not exist without them
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The Federal Power Act of 1920:
◦ Established government oversight over power
producing dams on “navigable waterways” of the
United States
◦ Established the Federal Power Commission to
regulate them
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Today that agency is the Federal Energy
Regulatory Commission (FERC)
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FERC licenses power producing dams
FERC’s regulations require the dams’ owner
to perform frequent engineering studies,
monitoring, environmental and emergency
management and to comply with its dam
safety standards
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The Probable Maximum Flood (PMF) is an
event calculated by FERC to occur once every
10,000 years
◦ By comparison, the flood of September, 1986 was a
between a 50- and 100-year flood event
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The FERC requires all “high hazard” dams to
be able to safely pass the 10,000-year flood
without failing (overtopping)
◦ The Edenville Dam is considered a “high hazard”
dam because its failure would likely result in loss of
life and property downstream at Sanford Lake
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Six spillways will be reconstructed to double
their capacity to pass flood water
◦ There are 3 spillways at the Tobacco River side of
the dam and 3 spillways adjacent to the Edenville
powerhouse on the Tittabawassee River side
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The total capacity of the six spillways is
currently 32,000 cubic feet per second (cfs)
(or 14,400,000 gallons per minute)
To comply with FERC’s mandate, the capacity
of the six spillways will have to be increased
to 64,000 cfs (or 28,800,000 gpm)
Current configuration of spillways
Tittabawassee side adjacent to powerhouse shown; Tobacco spillway is similar
FERC-Mandated alteration of spillways
Tittabawassee side adjacent to powerhouse shown; Tobacco spillway is similar
Example of cofferdam construction
Example of cofferdam construction
Example of cofferdam construction
Example of Cofferdam construction
Existing spillway construction
First concrete pour inside spillway (summer 2013)
New concrete pier extensions (summer 2014)
This work takes place
“in the dry” behind a
sheet pile cofferdam
Stoplogs are placed between piers & rest on new concrete sills
Once stoplogs are
in place water levels
can be returned to
normal
Construction work taking place between 2015 and 2016
Existing gate
and bridge are
removed
More concrete
is poured in
the base of
the spillway
Construction work taking place between 2015 and 2016
Concrete rollaway
slabs and most of
upstream barrel
arches are removed
Construction work taking place between 2015 and 2016
New concrete
crest is poured
Construction work taking place between 2015 and 2016
Concrete overlay is
placed over entire
pier structure
Construction work taking place between 2015 and 2016
New bridge is
constructed
Tobacco Spillway to be completed in 2016
New gate is installed
and stoplogs are
removed
Existing spillway
Modified spillway
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Half of the dam’s spillway capacity will be out of
service while the sheet pile cofferdam is in place
The drawdown provides a “buffer” as a
precaution so that the spillway structure that is
still open can be used to pass enough flood
water to avoid dam failure
30 years of data show that rainfall is least in July,
August and September
◦ While rare, floods have been known to happen in
summer
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FERC requires it for dam safety
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Starting in June, 2014 Wixom Lake will be
drawn down 8 feet for five months (until
October) then returned to normal levels
The reservoir will be maintained at normal
levels during 2015 and 2016 while
construction continues behind the stoplogs
The second draw down will start in June,
2017 when construction begins on the pier
extensions for the Tittabawasse spillway for
five months, then Wixom Lake will be
returned to normal levels in the fall and
maintained thereafter
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No. The PMF spillway modification will only
increase the dam’s ability to pass flood
waters
◦ During the drawdown for the Tobacco spillway
construction in the summer of 2014, production
and income at the Edenville powerhouse will
actually be significantly reduced
◦ The turbines are not able to run at full capacity with
so little head water
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No. When the Edenville (Tittabawassee)
spillway is under construction in 2017,
electrical production will be shut down
completely; there will be no income during
this time from the Edenville dam
◦ The entire spillway and powerhouse structure will
be blocked off with a cofferdam for five months
◦ A powerhouse is designed at the Tobacco spillway,
but its cost is not included in the spillway alteration
construction estimates
 this could be privately financed due to its incomeproduction capacity
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Yes. Boyce complies with all FERC-mandated
dam safety requirements
The Edenville dam is well maintained and is
structurally sound
Dam stability improvements and reinforcing
are ongoing for the safety and longevity of
the dam
◦ Boyce has spent over $1.3 million over the past six
years on these improvements at Edenville Dam
alone
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Boyce Hydro Power has negotiated with FERC
for more than seven years to reduce the PMF
requirement
◦ Engineers succeeded in reducing the requirement,
but FERC will not eliminate it
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There is no Federal funding or grant money
available to Boyce to pay for the PMF
alterations
◦ The PMF Spillway alteration does not qualify for
federal or state grants
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Net income after expenses from the
operation of the Edenville dam is less than
$200,000 per year
The cost of operations continues to rise, i.e.
materials, gasoline and diesel fuel, and
employee benefits such as health insurance
Private financing is unavailable
◦ The dam is already encumbered with debt
◦ The PMF spillway alteration does not increase
income
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Boyce is paid 30% less by Consumers than the
average of all the other 14 independent
hydroelectric power producers in the state
The rates being paid to Boyce by Consumers
Energy for energy production have not
increased in the last seven years
◦ There is continued downward pressure from
Consumers on rates, despite increases in energy
prices to end users
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The cost of this federally-mandated spillway
modification project is currently estimated to
exceed $8 million
Boyce does not have the capital to support
such a massive expense
Grants are also unavailable at this time
◦ The State provides some grant money to remove or
repair smaller dams, but not to comply with Federal
mandates
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We all want the same thing: the guaranteed
future of Edenville dam and Wixom Lake
Boyce, waterfront residents, and other
businesses depend on the reservoir
Public financing is one alternative to pursue
Let’s work together to find a solution to this
looming problem
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Strive to obtain and distribute accurate
information
Get involved with local task forces that have
been established to work with our elected
representatives
We will overcome these issues and ensure the
future of Wixom Lake for generations to come
by working together