Maryland State Highway Administration (SHA)
- Wetland Delineation
- Water Quality Data Analysis
- NEPA, Natural Resource Technical Report (NRTR)
- Impact Analysis
Coastal Resources, Inc. (CRI) assisted the prime engineering and NEPA planning consultant with natural resource field assessments, research, data analysis, and document preparation for the NRTR for the I 495 & I-270 Managed Lanes Study, which will be summarized for inclusion in the Draft Environmental Impact Statement (DEIS). The purpose of the I-495 & I-270 Managed Lanes Study is to develop a travel demand management solution that addresses congestion, improves trip reliability on I 495 and I 270, and enhances existing and planned multimodal mobility and connectivity within the project study area, which extends on I 495 (the Washington Beltway) from south of the American Legion Bridge in Fairfax County, Virginia, to east of the Woodrow Wilson Bridge, and on I-270 from I-495 to I 370 including the east and west I 270 spurs.
A detailed wetland delineation was conducted as part of the I 495 & I 270 Managed Lanes Study in Montgomery and Prince George’s Counties. CRI was responsible for identifying all Waters of the U.S., including wetlands in the eastern portion of the project study area, along an approximately 16 mile long by 600 foot wide corridor. All waters of the U.S., including wetlands, were identified using the U.S. Army Corps of Engineers (USACE) Coastal Plain supplement and functional assessments were completed for each wetland using the New England Method. A formal functions and values analysis was conducted for all wetlands greater than ½ acre in size and function and value suitability was noted for smaller wetland systems using best professional judgement. Over 40 acres of wetlands and over 15 miles of stream were delineated by CRI. Wetland boundaries were surveyed using GPS or verified from data previously collected in 2015-2016 for other projects along the corridor. GIS mapping layers were created of wetlands as well as other natural resources for use by the project team. CRI coordinated with natural resource agencies and regulators and led agency field reviews of representative, questionable, and high quality wetlands/waterways. All mapping, data sheets, and wetland/waters descriptions for identified waters of the U.S., including wetlands, were prepared in accordance with the technical field and data management protocols provided by the prime consultant and submitted for their use in preparing a delineation report to be included as an appendix to and summarized in the NRTR.
CRI assisted with the production of the NRTR document and drafted the water resources, terrestrial and aquatic habitats and wildlife, and rare, threatened and endangered species sections. CRI researched, gathered, and summarized existing data for these natural resources within the project corridor to establish existing conditions, as well as to evaluate potential impacts and environmental consequences of the proposed improvements. CRI coordinated with the prime consultant regarding supporting graphics and figures and provided GIS data as necessary. CRI will be responsible for addressing team and regulatory agency comments on these sections as needed and will assist in summarizing the NRTR for the DEIS.
CRI is also assisting the study team in developing a mitigation strategy with the MDOT SHA P3 Project Team and the resource agencies to offset potential impacts to aquatic resources associated with the I-495 & I-270 Managed Lanes Study. Both a traditional mitigation approach and a “full-delivery mitigation RFP” approach are being pursued as options for this study. CRI is assisting with the traditional mitigation site search and technical evaluation to identify viable mitigation opportunities that are conceptually suitable for mitigating unavoidable impacts to waters of the U.S., including wetlands from the Preferred Alternative, once it is selected.
During phase 1 of the site search process, CRI conducted a thorough desktop review to identify potential wetland and stream mitigation opportunities within the impacted MDE 8-digit hydrologic unit code (HUC) watersheds. CRI reviewed watershed reports from the last 5 years for the impacted HUC 8-digit watersheds, including the Middle Potomac-Catoctin, Middle Potomac-Anacostia-Occoquan, and Patuxent, to identify potential stream mitigation sites. Additionally, CRI identified stream and wetland sites within the MDOT SHA Site Selection geodatabase and geodatabase of sites dropped from consideration on other projects that might warrant further consideration for this study. Hydric soils, topography, aerial imagery and other relevant GIS layers were referenced to further refine the identified sites and develop a final site list. CRI also reviewed the Chesapeake Fish Passage Prioritization (CFPP) database and North Atlantic Aquatic Connectivity Collaborative (NAACC) database to compile a shapefile of potential fish blockage sites within the target watersheds. CRI assisted the prime contractor in conducting a non-invasive windshield survey of potential mitigation sites visible from public right-of way (ROWs). CRI was responsible for updating the SHA Site Selection geodatabase with the results of the desktop and windshield reviews for check-in and submittal to MDOT SHA at site search milestones. Once property access was granted, CRI conducted on-site field investigations and ranking of potential stream mitigation sites on publicly owned land, and conducted field assessments and ranking of potential fish passage sites within MDOT SHA ROW. CRI will be responsible for assisting with agency review of sites that are determined to be potentially suitable following on-site reviews and with developing conceptual plans for inclusion in the permit package for agency approval.