Prince William County Prefers Concentrated Development

Based on recent approvals and rezonings it is clear that the Prince William Board of Supervisors and Planning Department prefer concentrated development for Prince William County. They rationalize that they can use building techniques to protect the Occoquan Watershed as a substitute for maintaining open wooded areas. This rationalization is based on the belief that concentrated development paired with advanced technological mitigation can manage environmental impacts better than the "status quo" of rural development. I do not believe that they are right.  

The Board and Planning staff have argued that large-scale development allows for "unprecedented levels of environmental protection" that would not occur if the land remained privately owned and developed at lower densities. This is true, but it has served to protect the Occoquan Watershed for all of Northern Virginia.

Supporters, including Supervisor Kenny Boddye, argue that developers can implement specialized stormwater management systems that filter sediment and pollutants more effectively than the natural runoff from a privately owned 5-acre lot. There is no research for this argument either for or against.

Proponents also suggest that low-density rural development is less protected because the county has limited authority to regulate what chemicals (like fertilizers) private homeowners use or to prevent them from clear-cutting their own property. However, there are no restrictions on what chemicals hundreds of individual homeowners can use either. Small lot communities are notorious for their intense fertilization and management of the appearance of the community.

Though high-density approvals often come with proffered conservation easements that legally preserve a portion of the forest in perpetuity, there may be limited benefit to the watershed. The "edge effect" changes the soil moisture and temperature. This kills off sensitive native plants and allows hardy invasives to take over the ground layer. Within a decade, the small area forest has no "recruitment"—meaning no young native trees are growing to replace the old ones and it dies. The proffers contain no allowance for maintaining the forest.  In the Occoquan Watershed, a 50-acre contiguous forest is exponentially more valuable than five 10-acre "preserved" patches surrounded by pavement. The latter will almost certainly succumb to the "choke" within 15 years.

County staff have noted that while wooded areas help with traditional pollutants, "modern" concerns like increasing salinity (from road salt) are regional issues that require infrastructure-based management strategies rather than just land preservation. However, Extensive research, primarily led by the Occoquan Watershed Monitoring Laboratory (OWML) and published in journals like Nature, confirms a direct link between population growth and rising sodium levels in the Occoquan Reservoir. Average sodium concentrations at the dam have nearly tripled since the 1980s, now frequently exceeding health advisory limits. 

Research shows that for every 100 additional people per km², impervious cover in the watershed increases by 3%. This expansion leads to higher road salt application, with salt spikes occurring even as regional snowfall has decreased by 40% over the last century. In addition, approximately 64% of salt ions in the reservoir originate from the population via reclaimed water. You have more people and you have more salt. Also, research by Bhide et al. (2021) found that roughly 32% of the sodium mass in finished drinking water comes from the treatment plant itself due to chemicals (like sodium hydroxide) added to buffer pH and prevent pipe corrosion. 

The Planning Department's approach often involves "condensing development down" to specific areas, which they believe allows for larger contiguous blocks of undisturbed forest to be saved through cluster development provisions. However, the Planning Department has presented the arguments for the same density of housing on a clustered development for increasing the density of housing by 28 times. The Maple Grove plan for 279 houses naturally creates more total asphalt and roof area than 9 houses that could have been developed on that site by right. The "less impact" argument isn't about the total amount of impact, but about the intensity of impact per person. 

Despite these arguments, several major environmental and regulatory bodies have disputed the idea that these techniques can substitute for natural wooded areas. Fairfax Water & the NVRC have warned that runoff from new high-density sites could negatively affect drinking water for the nearly million residents that rely on the Occoquan Reservoir for their water supply.

Environmental groups note that large-scale development like the could lead to of tons of additional sediment flowing into the reservoir watershed annually and the Chesapeake Bay. Civic associations and community groups argue that approving high-density projects like Hoadly Square within the Occoquan Reservoir Protection Area (ORPA) "chips away" at the protection district right after its adoption.