Thursday, May 30, 2019

Restoring the Health of a Forested RPA

Prince William County is located within the Chesapeake Bay Watershed. All of the creeks and streams in the County eventually flow into the Chesapeake Bay. Thus, Prince William County adopted the Chesapeake Bay Preservation Act into its local ordinance in 1990. The Bay Act has guidance and requirements for property owners to protect and improve the water that flows into the Chesapeake Bay. This creates obligations and duties for property owners that they might not be aware of. Owners are responsible for determining if an RPA exists on their property.  If you violate RPA requirements, you will also violate county ordinances that can result in penalties. Welcome to the world of secret environmental regulations. 

The Regulations of the Chesapeake Bay Protection Act require that a vegetated buffer area of at least 100-feet wide be located adjacent to of all tidal shores, tidal wetlands, certain non-tidal wetlands, and along both sides of all water bodies with perennial flow within the County. These water bodies, along with the 100-foot buffer area on its edges are the Resource Protected areas or RPAs and serve to protect water quality by reducing excess sediment, nutrients, and potentially harmful or toxic substances from groundwater and surface water entering the Chesapeake Bay and its tributaries.

In the RPA the roots of the woody vegetation helps to maintain the stability of the stream bed, minimizing bank erosion to limit sediment. A wooded buffer has porous soils from leaf litter, fungi, twigs, fallen branches and associated bacteria all help to enhance the infiltration of the rain water and snow runoff. The root mass and forest floor also retains nutrients, aids in denitrification and pollution degradation. Property owners are responsible for determining if an RPA exists on their property. Violation of the RPA rules, also violates county ordinances and may result in penalties. The Environmental Services Division of Prince William County Public Works is responsible for approving any activities in the RPA including removal of trees and vegetation.

The almost seven acres of woodland behind my house is mostly part of the RPA. The woodland does not appear to be in good health. Until recently when emerald ash borer invaded the woods I felt we did not have to worry about dead trees, as it was all part of the natural process of renewal. However, the number of dead and dying trees has increased dramatically and it is obvious that the vines are preventing the dead trees from falling to the forest floor. The trees are just sort of hanging in the air, dangerously.

Though, honestly, as an engineer, I do not truly understand the nuances of the forest ecosystem. It is a complex mix of trees, under story shrubs and ground cover. In a healthy woodland the process of natural succession occurs over time. Small saplings develop and will become the next generation of trees as the older ones die out. Thought benign neglect is the rule for RPAs, my woodland needs some help beginning with removal of the invasive vines and the hanging dead trees. We contacted the Virginia Department of Forestry for assistance and guidance in this effort, highlighting that the woodland is part of an RPA.

Kinner Ingram, an Urban and Community Forestry Specialist from the Virginia Department of Forestry came out and inspected the woodland and made some recommendations that he is preparing in writing for me to submit to Clay Morris, Natural Resources Section Chief, Environmental Services Division of Prince William County Public Works for permission to remove the invasive vines and some of the dead trees. 

In order to do this I will need to apply for a Permitted Buffer Modifications under (9VAC25-830-140.5). The wooded area encompasses 6.9 acres about two-thirds in the RPA. Kinner will provide me with a roadmap for restoring the woodland health, but because this is an RPA it must begin with applying for permit for General woodlot management for the removal of the invasive vines and some of the dead trees to facilitate regrowth and regeneration of the woodland. This may be all that needs to be done, but it will take a few years to know if I will need to plant native tree saplings or additional work on preventing the reintroduction of the invasive vines. In addition, under the general buffer modification I would like a permit for the installation of a meandering access path. Both of these are allowed activities under Permitted Buffer Modifications.

I could not find instructions for the permitted buffer modifications process in the online materials for Prince William County. I have contacted Clay Morris at the Environmental Services Division of Prince William County Public Works Environmental Services Division for guidance in this process and make sure I provide all the information needed to grant the permit for this work before I begin.

According to the Department of Forestry In a woodland the roots, twigs and leaf litter and detrius are important for slowing storm water runoff and trapping debris and sediment. The twigs and roots also trap blown litter. Our spring clean- up of the RPA is to walk the woods collecting plastic bottles, and other litter. The access path will make this easier and allow us to enjoy the woodlands.


  1. Is there an application for modifying the RPA. I actually want to add some native plants to my RPA area.

    1. If you are in Prince William here is the RPA flyer with allowed activities on Page 3. You may need to contact Clay Morris at the Environmental Services Division of Prince William County Department of Public Works for guidance in this process.