National Harbor Off-Site Forest Mitigation Plans

Prince George's County, Maryland

National Harbor LG-Photography / iStockphoto

KCI performed a natural resource inventory (NRI)/forest stand delineation (FSD) for two properties as mitigation for impacts incurred for the National Harbor multi-use waterfront development. The Maryland-National Capital Park and Planning Commission (M-NCPPC) was looking to create a woodland conservation bank for off-site tree conservation credits for 149+ acres of property at Gardner Road Community Park and reforestation credit within the Chesapeake Bay Critical Area (CBCA) for 110+ acres along the Patuxent River at the Dyson Farm, Aquasco Farm, Isabell, and Hazelwood properties. KCI’s studies were used to estimate the location of forest resources, including specimen trees, wetlands, streams, and other natural resources within the site boundaries.

The Gardner Road Community Park site is a mid-successional forest containing numerous specimen trees and buffering a network of tributaries to Piscataway Creek. A simplified FSD methodology was used to characterize six stands throughout the site, differentiated by species, topography and understory characteristics. Our team walked the property, identified stand breaks; located specimen trees; and determined dominant species, understory and herbaceous species, percent canopy cover, and percent invasive cover. Photographs and other written notes were also collected throughout the site to characterize natural features.

The Dyson Farm, Aquasco Farm and Isabell properties are former agricultural sites, and the Hazelwood property is a former mining location. All are being allowed to reforest through natural regeneration. KCI scientists and landscape architects again used simplified FSD methods to characterize the new growth on each site. In most cases the new growth consisted of saplings and scrub-shrub cover as each new forest entered into secondary succession.

Landscape architects worked hand-in-hand with environmental scientists to compile existing natural resource information during the field investigation and to develop conservation plans.

Andrea E. Lake, RLA, LEED APLandscape Architect

Andrea E. Lake, RLA, LEED AP

Upon completion of the data collection, our team developed a written narrative and NRI mapping displaying all existing forest as well as other environmental features on each site using GIS data. Map features included topographic contours, forest boundaries, regulated streams and buffers, wetlands as identified through a published information review, 100-year floodplain, soils, specimen trees and all appropriate notes and tables.

Based upon the approved NRI/FSD mapping, woodland conservation worksheets were prepared to determine how much conservation would be available for credit. A Tree Conservation Plan II (TCPII) was prepared to illustrate all existing conditions identified through the NRI/FSD, and define protection measures for trees to remain on site, preliminary forest conservation easements and/or reservations, reforestation areas, as well as protection measures for environmental features.

KCI prepared Chesapeake Bay Conservation Plans (CBCPs) for the four properties within the CBCA. These plans defined requirements for long-term protection and natural regeneration. Each site was carefully reviewed to determine the total area available for reforestation credit through natural regeneration. KCI determined the total tract area for each site, the acreage within the CBCA, afforestation and reforestation areas, existing woodland within the 100-year floodplain, and areas within stream and wetland buffers.

Notes were developed that described each site, including its watershed, land use and zoning, rare/threatened/endangered (RTE) species habitats, forest interior bird dwelling (FIDS) habitat, and historic resources. Additionally, notes were generated to describe protection measures to be used at the site, including easements, signage, landowner agreements, and invasive species management.

Throughout the project, our team coordinated closely with M-NCPPC to ensure that these sites would provide the proper amount of credit needed to offset impacts incurred during construction of the National Harbor project. Over time, these properties will grow into mature forests that will provide habitat and water quality benefits both within and outside the CBCA.