Environmental Impacts of the Southbridge Development

Assessment of Environmental Impacts Associated with Southbridge

Development of Southbridge Town Center and housing development on the Cherry Hill Peninsula would have serious, long-range, deleterious environmental consequences. At risk is more than the peninsula itself. Because of its size, naturalness, topography, and proximity to significant waterways Cherry Hill is important not only to the county, but to the state and region as well. Walk the land. Read carefully the reports detailing Cherry Hill's resources, topography, and soils. Read carefully the details of its proposed development. Dire conclusions are inescapable. Visions of a gleaming community on the hill, shining in sunlight, are replaced by a more realistic view: a quagmire of eroded slopes, polluted streams, twisted promises, and broken dreams.

This report briefly looks at the site's relevant natural resources and the probable impacts development would have on them. The conclusions drawn are those of the author. But it should be noted that several state agencies, concerned with the overall quality of Virginia's environment, have reviewed Legend's proposal and reached similar conclusions. Indeed, our opinions are unanimous: on the basis of environmental concerns alone, Southbridge should not proceed. Here are some of the reasons why: January 5, 2000

Natural Resource: Vegetation

Instead, the Board of Supervisors Today, the Cherry Hill peninsula is extensively forested. Most of the site is classified as riparian forest, with smaller tracts of upland forest and open wetlands. Most trees are hardwoods, interspersed with small stands of pine. Over the last 200 years the area has been repeatedly clear-cut. As a result, most trees are roughly 25 years old; some, however, are over 100 years old. Under story plants are mixed and varied, with a variety of shrubs, small trees, and shade-loving herbs. Potentially, the site is home to the small whorled begonia, classified as threatened by both the federal government and the State of Virginia.

In order to make way for Southbridge, Legend proposes to clear-cut approximately 75% of existing forests. Laudably, they propose to retain approximately 40% of the area as "green ways." But over one-third of these would be managed grasslands-a golf course, soccer fields, school yards, power line rights-of-way, and the like. While vegetated and green in color, such areas provide habitat for neither native plants nor animals. Southbridge would reduce the forests of Cherry Hill to a few isolated tracts of trees.

Legend proposes to connect some of these areas with vegetated corridors-mainly power line rights-of-way. While these may provide corridors for some wildlife (see discussion below), plants in these communities would be isolated from similar plants in neighboring tracts.

Much of the remaining forests of Cherry Hill after Southbridge would be included in a system of buffers separating development from critical habitat areas, such as important waterways and bald eagle nest sites. However, Legend reserves the right to cross (clear cut and otherwise disturb) such areas if necessary during construction. After construction, Legend has agreed to restore the vegetative community by replanting existing plants. Such a proposal is ecologically unsound. Biological communities develop as a result of ecological succession. That is, bare ground is pioneered by a grassland community, which is replaced in time by a small tree community, and later by a succession of large tree communities. The process can take in excess of 25 years. Now, Legend proposes to step into the middle of this process-go from bare ground following disturbance directly into an early stage, large tree community. Successfully doing so is probably not possible. One cannot simply stick trees in the ground and have a 25 year old forest community.

The Southbridge proposal would clear-cut nearly 1300 acres of forests. The consequences of this act might well reach beyond the peninsula itself. American Forests has determined that healthy communities in eastern North America have at least 40% of their area covered with trees. In 1992, Prince William County was 49.9% tree covered. By 1999, percent of tree cover had fallen to 40.5%. Clear cutting Cherry Hill peninsula might well reduce Prince William County's tree cover below the critical 40% level. The County Board of Supervisors has a responsibility to maintain the environmental health of our county. To do so, it must, as a matter of policy, stop allowing the large-scale cutting down of trees. A start in this all-important process would be to disallow Southbridge.

Resource: Soils and Water

For the Cherry Hill Peninsula, soil and water are intimately inter-related. Inescapably, whatever erodes its soils degrades its water quality. A detailed discussion of the soils of Cherry Hill will be dealt with in another report. In summary, these soils are noteworthy because of two factors, extreme slope and erodibility. Cherry Hill is hilly. Three quarters of the peninsula has slopes of greater than 15% and over half of that has slopes of greater than 25%. The soils of Cherry Hill are mixed and varied with significant deposits of marine clay, sand, and other clays--all characterized as "highly erodible."

Cherry Hill is bounded on three sides by significant waterways. To the north is Powell's Creek; to the south Quantico Creek; to the east the tidal Potomac River. The Virginia Institute of Marine Science has determined that Powell's Creek is one of the three relatively unpolluted streams in northern Virginia-the only one in Prince William County. Quantico Creek, is somewhat more polluted, but is still regionally significant. Both streams flow directly into the tidal Potomac, an integral part of the Chesapeake Bay.

During construction of Southbridge, soil erosion would be nearly impossible to avoid. Legend proposes to build Cherry Hill "in the style of European villages," suggesting that some slopes will remain after construction. Still, slopes of 15% and 25% are simply not conducive to town centers, schools, soccer fields and the like. After trees are removed (see above), some hills will need to be topped off and gullies at least partially filled. Marine clays will have to be removed wholesale. During construction, what is to keep eroding soils from sloughing into Powell's and Quantico Creeks, hence into the tidal Potomac and thus the Chesapeake Bay? What guarantees do we have that the best possible erosion control measures will be adequate on Cherry Hill? Finally, what guarantees do we have that Legend will employ the best possible erosion control measures? Those are, after all, the most expensive and the least profitable.

Even under optimal conditions, the best possible erosion control measures depend on a measure of luck, i.e., no extreme storms or unusual wet seasons. These measures, laudable in their intent, are simply not designed to handle extreme conditions. Construction of Cherry Hill is expected to take several years. If massive soil erosion is to be avoided and if water quality is to be maintained, the weather during construction will have to be unusually cooperative.

After construction, the threat of damaging run-off would continue. As planned, 40% of the area will be retained as "green ways"-remnant forests and managed grasslands. Much of the other 60% will be converted into impervious surfaces-roadways, driveways, schoolyards, rooftops, parking lots, and the like. Land now covered with plants and spongy humus, that catch, hold, and slowly release run off, will be replaced with surfaces that promote run off. After every storm, water will gush into neighboring waterways, carrying not only loose soils, but more importantly, chemical pollutants unavoidably associated with urban regions. Recent studies show increased rates of diseased and injured fish living in streams in Prince William County that run through urban areas. These studies presage conditions in Powell's and Quanitco Creeks after construction of Southbridge.

Resource: Wildlife Habitat

The importance of Cherry Hill as habitat for wildlife is largely unknown. Legend, as part of their application for development, prepared an environmental assessment, which hardly mentioned wildlife.

Cherry Hill is undoubtedly important for birds. Wild turkey, several raptors, including bald eagle and osprey, and numerous songbirds are resident there in significant numbers. Two bald eagle nest sites have been located within the Cherry Hill forests. A third one was mysteriously destroyed, apparently last summer (2000). A single pair of bald eagles alternately uses these sites annually. Such a large tract of relatively unspoiled forestland is also important during migrations to an undetermined number of neo-tropical songbirds. Especially during winter, Powell's Creek and the near-by tidal Potomac provide habitat for waterfowl. Numbers and species composition of wintering flocks are unknown.

Resident mammals include white-tailed deer, red and gray fox, skunk, river otter, and a variety of rodents, including flying squirrel. While none of these species are threatened or endangered, the status of river otter, skunk, and flying squirrel are of special concern.

Wetlands surrounding and within Cherry Hill provide habitat for an undetermined number of fish species and populations. These wetlands and their surrounding forests provide habitat for a similarly unknown number of amphibians and reptiles.

Many of these animals (turkey, otter, migrating songbirds, and bald eagles) require relatively large tracts of uninterrupted habitat. For these species, Southbridge would fragment their habitat into tracts too small to support viable populations. These species would probably disappear from Cherry Hill. Of particular concern are the nesting bald eagles. Legend is required by law to provide an undisturbed buffer around the nest sites. But it is questionable whether the eagles would continue to use this island of habitat in a sea of urbanity. Probably, they would not. For other species, especially for smaller animals, remnant populations would probably remain, but at reduced population levels.

Grassland corridors are supposed to link tracts of remnant forests and buffers, allowing individual animals to travel freely between them. This might work for some species. But many species will not move into grasslands from forests. For these animals, Southbridge would result in small, isolated, unstable populations occupying limited habitat.

Resource: Comprehensive Plan

Southbridge would significantly compromise Prince William County's Comprehensive Plan, adopted in 1998. Supposedly, this document describes policies to guide and control development in the county. In one of its strongest points, the Plan calls for designating slopes of 15% or greater as "Resource Areas"-a special land use category on which development is to be restricted. This policy recognizes the inherent difficulty of building on extreme slopes (see above).

Roughly three-quarters of Cherry Hill has slopes of greater than 15%. Indeed, roughly 40% of Cherry Hill has slopes of greater than 25%. Clearly, the Comprehensive Plan intends that such areas not be built on. It recognizes the almost unavoidable erodibility of such terrain. Legend is asking for a waiver to the Comprehensive Plan in order to build Soutjbridge II. Such a waiver would set a bad policy. It would encourage other developers to seek similar actions that would further compromise the Plan's intent. The Board of Supervisors has a responsibility to in fact use the Comprehensive Plan to discourage and control unwise development. It should do so in this case.

Recommendations

Clearly, on the grounds of environmental considerations alone, Southbridge should not be built. Its inescapable costs in terms of water quality, soil erosion, loss of wildlife habitat, and loss of forested lands, are unacceptably high. We urge the Board of Supervisors to disallow this project and should recognize Cherry Hill as a Resource Area, paving the way for its designation as a park. As such, it would become an integral part of the coastal corridor of regional parks and natural areas linking Huntley Meadows to the north in Fairfax County with the Prince William Forest National Park to the south. Southbridge presents the Board of Supervisors a significant opportunity. An opportunity to say no to unneeded and unwise development. An opportunity to establish the primacy of the County's Comprehensive Plan in guiding development and preserving important environmental resources.