Resource Protection Area (RPA): Chesapeake Bay Preservation Ordinance

RPAs in Arlington County include streams, wetlands, and the area of land adjacent to these waters called the riparian buffer. These buffers extend at least 100 feet from streams and wetlands but can be wider where there are “critical slopes” (slopes steeper than 25%, or 45 degrees). Protecting trees and native vegetation in these areas helps keep our streams healthier and slow erosion on stream banks. Use these maps to find out if your property is in the RPA.

Most development in Arlington is redevelopment – the desired project will expand or replace an existing home or building. For these projects, the RPA permit approval process typically results in a negotiated solution that benefits water quality and allows the property owner to move forward with their desired property use. Some proposals for expansion or rebuild could require an Exception Request, and are subject to more stringent approval criteria. County staff can advise property owners regarding when the Exception Request is required and the likely outcome of their request 

RPA project review is not required for:

• Lawn care and gardening
• Minor home repairs  and maintenance work

Lawn Care and Gardening – Typical gardening activities are allowed, unless you are digging and exposing the soil of an area greater than 50 feet by 50 feet (2500 square feet) or removing native vegetation. Managing invasive plants and removing poison ivy from areas of native vegetation may require County review depending on how close the removal is to a stream or other protected water body, if the plants are located on steep slopes and how much removal will occur. Please email rpareview@arlingtonva.us for additional guidance before undertaking these activities in the RPA.

Minor home repair and maintenance – Home repairs and maintenance work are allowed within the RPA without County review and approval if they will not disturb soil or native vegetation

RPA Review Is required if your home project includes any of the following components (you must submit a Water Quality Impact Assessment for County review and approval).  Projects cannot be categorized as repair and maintenance if they will: 

• Change the length or dimensions of a structure or retaining wall,
• Create new paved surfaces, including gravel surfaces, within the RPA, 
• Add a new building 
• Remove native vegetation; or 
• Disturb soil or create bare ground within the RPA. Projects that disturb more than 2,500 square feet of soil also require a Land Disturbing Activity Permit (LDA)

For example, County approval would be required for a project to repair a retaining wall if it would increase the height or length of the wall. 

Any development or redevelopment project on properties where RPA is present requires RPA review. Any project requiring a building or land disturbing activities permit on an RPA property or that will remove trees or vegetation also requires an RPA review.  Depending on the location and extent, removal of invasive vegetation can also impact water quality by increasing the potential for erosion. Contacting the County’s RPA staff is recommended before starting invasive vegetation management in the RPA.

Types of projects that require RPA review and approval include: 

• Fences or retaining walls in the RPA 
• Adding new paved surfaces in the RPA such as driveways, walkways or patios 
• Tree removal in the RPA 
• Clearing of native vegetation in the RPA, including vegetation removal to createpaths, views or for general forest management in the RPA 
• Outbuildings such as sheds or pergolas in the RPA. 
• Expanding or adding a deck to an existing home on a property where RPA is present. 
• Tear down and rebuilds on a property where RPA is present.

An exception is required to:

• Increase impervious cover (rooftop, pavement, etc.) in the RPA
• Build closer to a stream or wetland

The Chesapeake Bay Preservation Ordinance Review Committee (CBORC) hears exceptions for development in the Resource Protection Area including:

• New detached buildings including garages, art studios, gazebos and  sheds;
• New retaining walls,
• New swimming pools,
• New patios or permanent firepits,
• New additions when the existing home is not in the RPA,
• Teardown and rebuild proposals that require an exception,
• New homes/buildings on vacant lots platted prior to 1989 proposed within 50 feet of the protected stream or wetland,
• Conversions in the primary RPA use such as the replacement of a single-family home with a sport court in the RPA.

Exceptions that don’t fall into these categories are typically approvable by staff. Typical projects approvable by staff include small additions, attached garages, and decks for a home already in the RPA.

Typical types of mitigation requested through the RPA process are:

• Tree replacement or protection
• Invasive plant removal
• Planting of native trees, shrubs, ferns and groundcovers
• Additional stormwater management measures
• Additional erosion control measures during construction
• Removal of impervious surfaces

Re-configuration of the development plan to reduce impervious cover, limit disturbance or protect trees within the RPA or for climate change adaptation may also be required. Each project's mitigation or adaptation requirement is proportional to the RPA or climate change impact. Specific examples are provided in the Stormwater Management Ordinance Guidance Manual (see How to Apply section of this page).

In general, development plans on properties with RPAs should result in enhancement of the Resource Protection Area buffer.

A Water Quality Impact Assessment (WQIA) form and a to-scale plan is required for County review. The WQIA describes the proposed project and quantifies its impact on the RPA. The plan, narrative, proposed mitigation measures, and supporting materials should be detailed enough to demonstrate how the project will comply with applicable RPA and water quality requirements.

County staff consider the existing condition of the RPA when they review project proposals.

• Improvement projects should strive to limit new hard surfaces, restrict disturbance in the RPA and protect existing RPA trees and other native vegetation.
• If RPA impacts can’t be avoided, mitigation should be proposed.
• In all cases, measures should be included to enhance the existing RPA buffer.
• Potential impacts to the development resulting from key climate factors including flooding, storm surge or sea level rise must also be considered.

To have a project reviewed, please complete and submit a Water Quality Impact Assessment form, and include Appendix H: Resiliency assessment if applicable. Providing a fully completed form and detailed information about your project will make it faster and easier for staff to review your proposal.

This project would require review and approval by the Chesapeake Bay Ordinance Review Committee. 

• Projects should strive to limit new hard surfaces, restrict disturbance in the RPA and protect existing RPA trees and other native vegetation.
• If RPA impacts can’t be avoided, mitigation should be proposed.
• In all cases, measures should be included to enhance the existing RPA buffer.
• Potential impacts to the development resulting from key climate factors including flooding, storm surge or sea level rise must also be considered.

To have a project reviewed, please complete and submit a Water Quality Impact Assessment form, and Exception Request Form, and and Appendix H: Resiliency Assessment if applicable (Appendix C, D, and H).

Small detached structures such as sheds or gazebos require an exception from the Chesapeake Bay Ordinance Review Committee.

To have a project reviewed, please complete and submit a Water Quality Impact Assessment form, an Exception Request Form, and Appendix H: Resiliency Assessment if applicable (Appendix C, D and H). 

Projects such as building a new home require review and approval and an exception may be required.

The property owner or their representative would fill out the  Water Quality Impact Assessment form and any appendices if necessary with information on their project and include it with the civil engineering plans typically necessary for permitting larger projects.

If a civil engineering plan or land-disturbing activities (LDA) permit is required, the RPA boundary must be delineated as part of the site survey..

Mitigation, such as additional plantings or stormwater management, typically is required for tear down projects, particularly for projects that add new impervious cover in the RPA or that extend further into the RPA.

Yes, even if the project is outside the RPA area on your property, the project is reviewed to ensure that it will not negatively impact the RPA or water quality.

An assessment of flooding, sea level rise, and storm surge must be completed for any planned development within Resource Protection Areas to determine the potential impacts from climate change. This assessment is part of the Water Quality Impact Assessment form. In some cases, Appendix H: Resiliency Assessment may also be required. Not all properties will experience impacts from these climate factors. The County has created an interactive map, the Climate Resiliency Lookup Tool, or a PDF map  to help you determine if flooding, sea level rise, or storm surge could affect your property.

Yes, County staff can consult with you about projects or development activities you are considering and how having RPA on your property could affect those plans. 

Reach out to County staff to schedule a phone call or meeting. A copy of your plat marked with the location of the RPA boundary and the planned improvement may be requested by staff. A draft Water Quality Impact Assessment form and a tree impact and mitigation plan can also be useful to inform staff about your approach. Meetings are typically scheduled during business hours. 

For larger projects that require a land disturbing activities (LDA) permit, there is a fee for the RPA review as part of the permitting process. Check the Permit Fee Schedule for the current fee for single family home projects.

Please check Arlington County tree removal requirements web page. Trees that are in Resource Protection Areas (RPA) or historic districts, or that are designated as specimen, heritage or memorial trees are protected from removal or injury.

The County’s Chesapeake Bay Preservation Ordinance and RPA policies support conservation of RPA trees. Removal of healthy trees in the RPA must be permitted by the County and replacement is required in accordance with the County’s tree replacement guidelines. These guidelines use a condition rating based on a tree’s size, health, and species to identify the appropriate number of replacement trees. A condition assessment by a Mid-Atlantic Chapter – International Society of Arboriculture (MAC-ISA) certified arborist or person accredited by the American Society for Consulting Arboriculture must be provided with each tree removal request. Tree replacement calculations should be a component of the arborist report.

A request to remove an RPA tree should include the certified or accredited consulting arborist’s report and an exhibit identifying the RPA on the property (per Arlington County mapping), the location of the tree(s) that will be removed, and the location of the new tree(s) that will be planted. The quantity, size, species, and timeline for planting any new trees should also be provided. Replacement trees must be planted within six months of removal. The minimum size is¾ - 1 inch caliper.   A Water Quality Impact Assessment data sheet identifying the rationale for the tree removal must be included with any request to remove healthy RPA trees. Requests for tree removal must be submitted by email to rpareview@arlingtonva.us.

Trees should be topped at 15-20’ in height to retain some wildlife benefit. The root ball of the tree should remain in place to continue to stabilize the soil.

Native trees suitable for the location should be planted. The riparian buffer plant list put together by the Virginia Department of Conservation and Recreation is a great resource. The minimum size for replacement is ¾-1 inch caliper. Trees planted between October 1and May 1 are most successful in our region.

Vegetation removal requests that are not associated with a building or land disturbing activities (LDA) permit can be reviewed within 5 days after an email submission, and no fee is charged. Vegetation removal requests associated with a building or land disturbing activities (LDA) permit will occur in accordance with the permit and fee schedules for those permits. Fees for review of a water quality impact assessment are included on the Department of Environmental Services fee schedule under the Land Disturbing Activities heading.

RPA trees must be pruned by a MAC-ISA certified or accredited consulting arborist. Discretionary pruning, such as pruning to remove otherwise healthy growth for sight lines, or to open the canopy to increase sun on your property, requires review by Arlington County. Pruning to remove dead branches or other potential hazards can be undertaken without review, but maintaining written documentation from the arborist documenting the purpose of pruning is recommended.