RCS Weighs In on Water Supply Plan

 

April 10, 2008

 

This letter was sent to all members of the Charlottesville City Council and the Albemarle County Board of Supervisors

 

Localities throughout the Rivanna watershed are currently grappling with major water and sewer infrastructure projects which will significantly impact our communities’ environmental footprints for the next twenty to fifty years and beyond.  Since our group’s inception, Rivanna Conservation Society (RCS) has been actively involved in these debates, and we will continue to do our best to ensure that local decision makers build strong environmental protection measures into systems designed to meet reasonable human needs and desires from limited surface and groundwater resources.

 

We recognize that a local group has recently been critical of the local water plan developed by the Rivanna Sewer and Water Authority (RWSA).  I wanted to reiterate RCS’s support for that plan and the process by which it was adopted.   The ongoing debate about the engineering details and cost effectiveness of various locally-based water supply options clearly validates RWSA’s and the Charlottesville / Albemarle community’s recognition that present and reasonable future municipal water demand can be met locally without resort either to additional dams across currently free-flowing streams or to water imports from outside the Rivanna River watershed.

 

A comprehensive discussion of the various proposals is beyond the scope of this communication, and for this reason I have outlined the view of our Board of Directors on a few key issues:

 

1)   Restoring a semblance of natural flows in the Moorman’s River between Sugar Hollow and South Fork Rivanna River (SFRR) reservoirs is a longstanding goal which RCS has shared with Friends of the Moorman’s and other local environmental advocates.  The Rivanna Water and Sewer Authority (RWSA)’s “local water” plan would achieve this by replacing the decrepit pipeline from Sugar Hollow to Ragged Mountain Reservoir with a new pipe from SFRR to Ragged Mountain.  Stored water from Sugar Hollow would be released to SFRR via the Moorman’s River, itself, thus restoring Moorman’s flows to levels which could match or exceed the “natural” run of the river flows.  We are concerned that a long delay in construction of the new SFRR-Ragged Mountain pipe could extend the period during which RWSA is heavily dependent on water from Sugar Hollow, with continuing depletion of natural flows in the Moorman’s during dry weather.  As a starting point, RCS urges RWSA to quickly develop and implement a long-term monitoring program to obtain and publicize accurate flow data for the Moorman’s above Sugar Hollow Reservoir, from which reasonable estimates of “natural” flows below Sugar Hollow Dam can be derived.

 

RCS and a broad coalition of local environmental advocates lobbied vigorously for RWSA to adopt its current “local water” scheme in preference to an alternative plan based on a long pipeline to the James River.  The current plan includes an environmental tradeoff – if RWSA is to increase its capacity to a level sufficient to meet future demand based on recent population and per capita use trends in the utility’s service area – in the form of a higher dam and expanded reservoir capacity at Ragged Mountain.  Filled to capacity, the expanded reservoir would flood a large portion of the Ragged Mountain Natural Area, an important and much beloved local environmental and recreational asset. 

 

Such a step is not one to be taken lightly; however, the impact would amount to a rearrangement of a small watershed which has been already drastically altered from its natural state since the construction of the original Ragged Mountain upper dam in 1885 and the lower dam in 1908.  In exchange, the proposed new pipeline opens the prospect of substantially improved environmental conditions along a large free-flowing section of the Moorman’s River. 

 

2) It is a basic fact of gravity and geology that the space behind any natural or man-made dam across an active stream bed will eventually fill with sediment.  RCS takes it as a given that water supply reservoirs, stormwater control basins, and similar basic pieces of local water supply and environmental protection infrastructures all require periodic dredging in order to remain functional.  RCS – beginning years before the current round of “local water” supply debates – has repeatedly urged RWSA to develop a long-range plan for maintenance dredging of South Fork Rivanna Reservoir.

 

It is important to note the difference between the local sub-watersheds surrounding both the South Fork Rivanna Reservoir (SFRR) and the Ragged Mountain Reservoir (RMR).  Much of the SFRR watershed is heavily developed and has long been subject to a variety of natural and human-induced erosive forces which result in a high rate of sedimentation.  There is no reason to expect that this fact will change to any degree in the foreseeable future.  The Ragged Mountain Reservoir watershed is much smaller, densely forested, and publicly owned and controlled for the specific purpose of water supply protection.  So long as those conditions persist, RMR will not be subject to the sediment load that the SFRR experiences and consequently should require much less maintenance to preserve its water supply capacity.   Along the active bed of the South Fork, by contrast, recent estimates suggest that maintaining capacity requires annual removal of at least 75,000 cubic yards of sediment.   

 

So long as recent growth trends continue, Rivanna watershed localities will face important and controversial decisions as to how the costs of new infrastructure should be divided among various user groups—i.e. what proportion of expenses should be billed to the new utility users who generate the need for infrastructure expansion; what proportion to the current utility customers for whom the existing infrastructure is generally adequate (with important exceptions such as the need to meet higher standards of pollution control and treatment); and what proportion to landowners outside the areas served by publicly subsidized water and sewer systems. RCS acknowledges that financial decisions of this sort may be critically important to local rate and tax payers, but we will generally regard these discussions to be outside the realm of the RCS environmental mission.

 

Thank you for your consideration of the views of the Rivanna Conservation Society.

 

Sincerely,

 

 

Angus Murdoch, President

Rivanna Conservation Society

 

Cc: RCS Board of Directors

 

 

This letter has been sent to the following individuals:

 

County of Albemarle

Kenneth C. Boyd, Chairman

Lindsay G. Dorrier, Jr. 

Ann H. Mallek

Dennis S. Rooker

David Slutzky 

Sally H. Thomas

 

City of Charlottesville

Dave Norris, Mayor, City of Charlottesville

Julian Taliaferro, Vice Mayor

David Brown

Holly Edwards

Satyendra Huja