RWSA Considering an Earthen Dam

The Rivanna Water and Sewer Authority is looking at building an earthen dam for Ragged Mountain Reservoir, Brian Wheeler writes for Charlottesville Tomorrow. It would be built downstream from the existing dam, but taller, allowing an extra 45 feet of water in the reservoir. This is instead of the prior plan, which called for a concrete dam. That would have cost between $70M and $100M; this new one would run between $29M and $37M. The RWSA has not yet determined if they’re going to build a dam, extend the existing one, dredge the reservoir, or do nothing at all.

11 thoughts on “RWSA Considering an Earthen Dam”

  1. Whatever it is they plan on doing the Army Corps of Engineers or some Federal governmental body requires that additional work be done to the Ragged Mountain Dam to bring it up to code with regards to “Safety standards.” And that has to be done regardless of whatever else is done. It seemed to me if it could’ve been lumped together with another project their might’ve been some cost savings. Has anyone looked into that?

    So no Dam upgrades. No cost savings. RWSA just continues to waste money on navel gazing studies. Typical Charlottesville.

  2. @Just Bob, the Army Corps of Engineers has required the City (not RWSA since it doesn’t own the dam, just renting it) to repair the spillway. The City is not gazing at its navel, it is now funding the studies that should have been done years ago BEFORE people thought they could brainstorm their way to an engineering solution rather than collect the necessary data as intelligent people would do.

  3. If I’m in Error I blame RWSA Fredrick for the misinformation. Since that’s what he said almost verbatim at one of those “Trying to sell” the James River Pipeline meetings.

  4. I remember the statement and interpreted it much the same (as if the dam could collapse soon), so thanks Cville Eye for the clarification.

    If one looks at the conceptual map provided in the writeup, the earthen dam requires a large amount of soil to be gathered/removed. The removal area is marked on the map around the outer eastern ridges of the lake. The removal area is large; it appears be about 2/3 of the total acreage of the new lake. This assumes the lighter blue on the map marks the additional storage capacity created by the new dam.

    Though the earthen dam is a considerable savings, it appears to leave a much wider footprint into areas that are currently trails/forested.

  5. So much has come out of the RWSA office no one really knows what to believe. Im wondering exactly what would be the environmental impact of the earthen dam proposal. Will be be losing 54,000 trees for example/
    I think one of the questions now that needs to be answered is, Will we really need to be able to store 2.2 billion gallons of water just in case we experience aother drought? Thank goodness the State is requiring us to conduct another future usage evaluation in 2011.

  6. Why can’t they take the soil from Dredging the South Fork Rivanna and use that for the Earthen Dam?

  7. A year ago, when this whole water supply project had ballooned to plus or minus $200 million and dredging appeared all but dead, the RWSA position was ‘full speed ahead!’. Now, and only now that dredging seems to be getting more traction and appears at first glance to be by far the more cost-effective solution, The RWSA comes up with an alternative that [maybe] saves money. Where was the cheaper earthen dam when Gannett Fleming was spending millions on studies and charrettes? They’d probably have you believe that the ‘big pile of dirt’ approach is an evolving technology! It seems like if dredging came in at $20 million, the RWSA would claim they could build a new dam out of popsicle sticks for $15m.
    My serious question is this: When, 30 years from now, we need yet more water supply capacity because the RWSA has 1. let the South Fork Rivanna Reservoir silt in, 2. Grossly underestimated how much silt gets pumped from the now riverine SFRR to Ragged Mt., 3. lost capacity at Sugar Hollow through neglect and pandering to the Nature Conservancy, will it be possible to increase capacity at Ragged Mt. through the use of a bladder or by otherwise raising the pool elevation significantly if the dam is constructed of dirt? Or will we build another taller and more expensive one just downstream again?
    I would think engineering and building a concrete dam for future additional supply would be pretty straightforward, not so sure about a dirt one.

  8. @****, Good questions. We also need to consider that in thirty years, as potable water becomes more and more scarce in this country, localities may lose the right to control local water supply. They may also lose the right to use as much water as they wish. In ther words, we may not be allowed to stockpile 2.2 billion gallons at Ragged Mtn. waiting for a drought. All of those $$$$M may be spent in vain.

  9. Water is something you have or don’t. If you don’t have it and need it, you will be paying BIG $$$$. It is always best to have more than you need and hope you don’t never need to use it all.

    What the plan should be is to maximize the 3 water sources that we do have, Rag Mountain, Sugar Hollow and South Fork. All 3 need to be dredged. If the nature loving people don’t watch it, that 4th reservoir will be needed sooner than later. Buck Mountain may have James Spinymussel, but when your children turn on the taps and nothing comes out, they will be thanking you for saving the James Spinymussel. It’s time to relocate them and/or also they are found in other places

    We are already 10 years into the 50 year plan, without a solution. Again, you can never replace the need for water. You best have it.

  10. It has never been documented that the James spineymussel was seen in the waterways of Buck Mountain. In 2004, it was recommended that a Dr. Neves of VA Tech be employed for this documentation, but I have been unable to find anything else beyond that.
    I remember that when the drought of 2002 ended we still had 60 days f water stored that we could use before we had to use stringent water-saving methods. I also remember that Judith Mueller said publicly that Chriss Green Lake and Mint Springs water could be used to supplement the water supply. We never got into those sources.
    It’s funny that they now bring up the earthen dam when the city started to conduct research into the actual needs of the water supply. I think the city ought to dissolve RWSA and sell the water to the ACSA as it does to UVA now.

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