RWSA Evaluates Two Dam Cost Estimates

The Rivanna Water and Sewer Authority (RWSA) yesterday released two conflicting sets of cost estimates for the engineering and construction of the expanded Ragged Mountain Dam.   While the Free Enterprise Forum has not endorsed any specific community water supply option, we applaud the very public process the RWSA is pursuing.

Both cost estimates were increases from the concept costs provided during the 2004 community water supply meetings.  In response to these competing estimates Tom Frederick, Executive Director of RWSA ask for Board approval to seat a professional panel of national experts to evaluate the differences between the two estimates.  In addition, Frederick indicated that RWSA would cease work on the dam project until this panel had been seated and made its recommendation to the RWSA board.  Brandon Shulleeta has the story in this morning’s Daily Progress.

In his memo to the RWSA Board, Frederick identified the drivers that resulted in the most recent cost adjustments:

The largest engineering challenge in designing a dam is to capture geophysical data regarding the location and integrity of hidden, underground rock formation, and to interpret this data to define the extent of excavations and size of the underground foundation.  Given this challenge, adjustments to conceptual design assumptions are very common at this stage of the dam design process.  To date, much of the Ragged Mountain preliminary design has been focused on obtaining and interpreting this geophysical data.  This information is expensive to collect, yet extremely important, as the decisions regarding the design of the dam foundation can have a major effect on the overall quality and cost of the project.

Faced with an new estimated cost from Gannett Flemming of over $70 Million,the RWSA staff believed a second opinion was needed.  On August 12th RWSA staff directed Gannett Fleming to stop work, and RWSA reached out to Schnabel Engineering to conduct a very limited review of Gannet Fleming’s work interpreting the geophysical data and the cost estimates related to this data.

The Schnabel report highlights one of the challenges with the 2004 estimate:

Starting in 2004 and continuing into 2007, there has been an appreciable rise in the cost of construction materials, especially diesel fuel.  The project costs of many high profile dam projects had bid prices well above the estimates made by engineers during this period because of these rapidly increasing costs.

Schnabel’s report goes on to identify 15 different downward adjustments to Gannett Flemming’s design and cost estimate.  In addition, the firm interviewed two different dam contractors to gauge the current market receptivity to bidding out such a project:

The contractors interviewed indicated that present conditions (i.e. 4th quarter 2008) facilitate a good bid environment for owners with this favorable condition likely extending into 2009, if not 2010.  With the economy depressed, material prices are not likely to see large increases in the near future.  Cement sales are predicted to decline by more than 10% this year and 5% in 2009.

While opponents of the Ragged Mountain Dam have taken this opportunity to call for resignations of the RWSA Board, The Free Enterprise Forum believes the opposite is true. 

The RWSA Board (and the staff led by Executive Director Tom Frederick) should be commended for their commitment to public engagement.  The detailed reports prepared by the consultants were made readily available.  Since the inception of the community water supply planning meetings, given the choice, RWSA has routinely opted for transparency and sunlight on the water supply decision making process. 

While individual citizens may disagree about the direction of the community water supply initative, the fact that these conflicting engineering reports are open to the public is helpful to building the community understanding of the process.


One response

  1. Lenthalls Dam Washout | Reply

    Lenthalls Dam Washout // Oct 12, 2008 at 3:28 pm

    Dams are amazing structures and we rely on the engineers who build and manage them to keep them working and safe. Engineerings work very hard to keep us safe. I am concerned though that in Australia those high standards may not be what they were. It is in the public interest to ask if complacency has set in.
    In Australia our family almost lost 3 members due to dam gate failure when the Emergency Action Plan for Lenthalls was in draft, incomplete and unfinished. We were shocked and disapointed.

    I have concerns that Australias water infrastructure managers may not be up to the responsibilities involved.
    By this I mean the states, water corporations like Wide Bay Water and local governments.

    Our own experience of dam gate failure at Lenthalls Dam on the Burrum River is a telling – it is indicative of an inability to understand risk and manage public saftey issues

    You would imagine that Dam infrastructure in Australia is safe – however our experience on the Burrum River in QLD shows just how easy it is to become a fatality when Dam Infrastructure fails.

    Gates constructed in December 2007 at Lenthalls Dam on the heavily impounded Burrum River failed to lower to release flood water as designed in Febuary 2008.
    Wide Bay Water was the constructing authority and responsible for the design and operation of the dam gate infrastructure.
    Our upstream farm house, where the tributaries join the dam proper was cut of when flood water continued to back up much higher than the constructing authority Wide Bay Water had predicted the water levels would ever go.
    Three family members were stuck at our farm house. The emergency evacuation plan found in the Lenthalls Dam Emergency Action Plan called for evacuation after water levels reached RL26.91 – water levels reached 27.4 at the dam wall flowing over the blocked gates and backed up to RL28.5 at our house. No one evacuated the famuily members stranded in rising water.
    No one from the constructing authority Wide Bay Water contacted us to undertake evacuation or explain the risk we faced due to Crest Gate Failure.
    We believe the CEO Tim Waldron was overseas at conference when the event happed. The Operations manuals for the dam place responsibilty with the CEO as does the action plan. He has not been called to account for his failure to take responsible action to ensure an evacuation would occur in his abscence if required.

    If the rain event had not stopped the three people cut off at our flood impacted farm house would have been inundated by metres of water.

    We heard about the dam failure from other locals close to the dam wall who had heard the gates have failed – we now have full evidence to verify the dam gate failure.

    What our situation highlights is that while most fatalities from failed dams and failed dam infrastructure have occurred in the countries of the south ie third world the west is not imune from dam infrastructure failure.

    The capacity of first world dam operators to manage infrastructure/ risk and operational and human failure is not consistent.
    We were very lucky the rain event that caused the flooding to back up over the failed dam gate, stopped.
    It is however only a matter of time before a dam infrastructure failure in the first world causes fatalities.
    We feel that maybe operational and human failures that have occured without fatality have been coverd up and are not generally reported or researched.
    It is likely constructing authorities keep these instances quiet. I think the public and engineers who work with Dam Saftey can learn a lot from our experience.

    Please see the small news article that did report the event ( not comprehensively).

    See the article:
    Resident fears dam gates risk flooding
    Posted Wed May 21, 2008 8:26am AEST
    Updated Wed May 21, 2008 8:25am AEST
    • Map: Hervey Bay 4655
    A land-holder upstream of a major dam south-west of Hervey Bay says multi-million dollar barriers on the storage are broken, putting her family at risk of flooding.
    Queensland Deputy Premier Paul Lucas will officially open the $16 million project at Lenthalls Dam, which is designed to more than double the storage’s capacity.
    In what is claimed to be an Australian first, the two metre high crest gates sink when the dam reaches capacity to prevent flooding upstream and provide for environmental flows.
    But Esther Allan says in February the gates jammed, causing water to back up onto her property.
    “This is an extremely expensive piece of infrastructure. Ratepayers paid for this and their expectation would be that it would be operable,” she said.
    “If it wasn’t, we need to know why – not only because our family’s safety was put at risk, but because ratepayers expect to get a result from the infrastructure they pay for.”
    The local government corporation that runs Lenthalls Dam says the gates do not work, but it was monitoring the rising water.
    Wide Bay Water general manager David Wiskar says adjustments were needed during the dam’s commissioning and are continuing.
    “The gates were all needing some fine-tuning. At the moment we were able to complete that tuning on three of the gates,” he said.
    “There’s two that remain to be done, but we’re waiting until the level in the dam falls to an adequate level to [do] those final two.”
    The Lenthalls Dam Gates are still not fully operational today September 2008 and heading into the QLD summer flood season.

    We can evidence what we are saying.
    We dont have too much faith that any government authority will maintain our saftey, and our economy is currently healthy and well economically resourced.

    Infrastructure once built needs to be operable ongoing through good economic times and bad. Infrastructure needs to be able to operate as designed in all conditions.

    Climate Change will continue to place increased pressure on infrastructure in Australia the frequency of extreme storm and weather events will be a counterpoint to extreme drought.

    The risks remain for all of those who live on dammed river systems

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