Maryland State Highway Administration – Environmental Programs Division
- Stream Assessment and Restoration Design
- Environmental Permitting
- Water Quality Improvements
- Natural Resources Inventory/Wetland Delineation
- GIS Analysis
- Aquatic and Riparian Habitat Analysis
- Invasive Species Management
Coastal Resources, Inc. (CRI) provided design services for the Maryland State Highway Administration’s (SHA) Intercounty Connector (ICC) Environmental Stewardship (ES) stream restoration site PB-37. CRI provided natural resource inventories, wetland delineations, forest stand delineations, stream monitoring, geomorphic assessments, hydrologic and hydraulic analyses, stream restoration design services, and environmental permitting, and designated specialist services/construction oversight. PB-37 is a first order urban stream located within the Upper Gum Springs subwatershed of the Upper Paint Branch watershed. The study area included approximately 5,100 feet of the Gum Springs mainstem and its tributaries. Gum Springs has been historically impacted by urban development, resulting in a shift in its hydrologic regime and significant in-stream sedimentation that is impacting water quality downstream, and the urban coldwater fishery of wild brown trout. The primary goals for the site included reconnecting the stream to its floodplain, reducing channel incision, reducing bank erosion and in-stream sedimentation, maintaining the habitat and benthic communities, removing fish blockages, and enhancing the fish community.
A Preliminary Data Report was prepared in 2006, and a Final Data Report was prepared in 2008 documenting the existing morphology, and associated natural resources within the study area. Subsequently CRI conducted additional geomorphic assessments, and hydrologic and hydraulic analyses. The site was divided into several study reaches and evaluated to assess the current geomorphic condition of the stream and to provide preliminary estimates of the extent, magnitude, and rate of instabilities throughout the site. Geomorphic measurements such as cross sections, profiles, and pebble counts were repeated later in the design process to confirm unstable reaches. Historic maps and photographs were reviewed to evaluate land use changes within the watershed, and stream channel plan form changes over time. Wetlands on the PB-37 floodplain were delineated and riparian vegetation density and composition was observed. Areas in need of restoration/stabilization were identified, and remedial designs developed. The design addressed eroding stream banks and habitat degradation throughout the project area, while ensuring that existing infrastructure would be protected. Stream treatments included riffle grade control, stone toe, step pools, natural fiber matting, and bioengineering. Invasive species in the riparian buffer were also mapped, and invasive species treatments along with appropriate native species plantings were included in the design plans.
CRI prepared the Joint Permit Application, Semi Final (60% design), Final (90% design), and PS&E (100% design) submittals, and erosion and sediment control plans. CRI also presented the design strategy to review agencies at Interagency Workgroup (IAWG) and Brown Trout Advisory Workgroup (BTAWG) meetings and acquired all environmental permits, and erosion and sediment control permits. Final Design Plans, Specifications, and Estimate for the restoration of the PB-37 site were completed in 2011. CRI also provided Designated Specialist services during construction, which was completed in 2012.