Monday, October 18, 2010

Local Biologist Argues for an Ecologically Responsible Water Supply Plan

Dan Bieker is a local biologist who teaches field ornithology at Piedmont Virginia Community College and is the former president of the Ivy Creek Foundation. He recently penned some comments about the need to strike a better ecological balance in our planning for a long-term community water supply and I am reprinting his words here with permission.

Many factors are interwoven in water supply issues, and environmental concerns are certainly important ones. To many, it’s been alarming that so little attention has been given to ecological consequences of a full height dam at Ragged Mountain Natural Area (RMNA). Besides the loss of trees (150 - 180 acres removed), also noted are: loss of wetlands, negative effects of forest fragmentation, widening of roads, spread of invasive plants, and other factors.

While these factors are difficult to quantify, and well-meaning input has come from various sources, it’s not misleading to note that impacts to the area will be more than the loss of trees.

Habitat Loss:

The contiguous nature and maturity of the forest composing RMNA and surrounding lands affords protection for many uncommon (and declining) plant and animal species. No one has contended that the area is 100% canopy enclosed - indeed several roads, driveways and other openings exist, although extensive forest interior remains. The most blatant fragmentation is Interstate 64; while its existence for the public good might be justified, it obviously represents a degradation of the native habitat. Throughout the environment, negative effects of habitat disturbance and fragmentation are an ever increasing problem. In 2004, an Albemarle County Work Group composed of area biologists, UVA research professors, and VA Dept. of Forestry personnel issued a biological assessment of the County - in it the threats to Albemarle’s forests are well documented. Large tracts of mature forest are a noted habitat type of special concern - indeed, the Ragged Mountain forest is included in a list of special places recommended as most deserving of preservation. Questions concerning the degree of impact from proposed construction are justified - however, inferences that the impact will be minimal or that not enough forest interior exists to be affected, are not.

Expanded Reservoir Pool:

While the existing reservoir itself is a fragmentation, the forest directly abutting the water does not impose the same effect that a terrestrial opening does. Initial filling of the expanded bowl is proposed via the Sugar Hollow pipeline (which will impose additional demands on the Moormans River during this time) and could take several years - leaving a large swath of opening around the lake, much decreasing the interior nature of the surrounding woodland. It’s true that over time the disruption will heal, but it will take decades. The direct loss of habitat and diminishment of forest interior will be permanent. Most of the same species that are there now will continue to be there - more of the common species, but fewer of the more rare and decreasing ones.


It’s been noted that all new roads will be designed to be submerged by the final pool height (45 feet above current level). However, many questions remain concerning the degree of disturbance to existing roads that will be necessary to accommodate heavy machinery. Sections of an old service road near Ednam Forest will need to be accessed for interstate upgrades, and some modifications will need to be made to Reservoir Road (although that road will be affected no matter which water plan is adopted).

Stream Flows/Health:

Stream flows are a critical component of water supply, and rightly so. Since stream flows in the Moormans River are affected by how the pipeline from the Sugar Hollow Reservoir (SHR) is managed, increased storage capacity in downstream reservoirs through dredging and/or increased dam height at Ragged Mountain will allow for greater flexibility in managing flows, until or if a different pipeline is deemed necessary. Minimum flows vs. natural flows are an important distinction - imposed definitions for minimum are by necessity subjective; natural is what it is. Critical to determining natural flows are accurate stream flow monitors both above and directly below the SHR, which do not as of yet exist. Assessing stream flow data for infrastructure planning purposes would be better assisted by that data, rather than a complicated set of parameters from gauges on other rivers. Central to river health, as well, is how much water is consumed. Whether taken directly from the river or moved to storage, the natural cycle is disrupted. In that regard, pro-active, technology based conservation could be a huge factor, both in degree of infrastructure that's necessary, and river health. In 40 - 50 years, using the (arguably inflated) demand projections, a 25% conservation factor would mean approximately 4 million gallons a day less water drawn from the river system, and re-released as treated effluent. Pros and cons exist to all aspects of water supply options, though certainly phased, as-needed infrastructure development would better allow for conservation benefits and incentive, and potentially far less impact to RMNA.

As the 2004 Biodiversity study points out: as the landscape becomes more developed - more roads, housing, infrastructure - our remaining forests and other undisturbed areas become even more critical as repositories of biodiversity and the ecological services they provide. Of course we necessarily make demands on the environment for our survival, but we have long passed the point where we can do so without just and demonstrable cause, especially on a project of the scale being considered. Whether the environmental damage at RMNA is deemed justifiable or not, we’d do well as responsible stewards to accurately assess ecological impacts, and not undervalue the few wild places that remain.

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