Projects

Windmill Branch (Bridge Street) Stream Restoration Project

 Coastal Resources, Inc. (CRI) is providing environmental and restoration design services for the stream restoration of Windmill Branch located in Easton, MD.  The proposed project area extends from South Washington Street to Mecklenburg Avenue and includes approximately 1,325 linear feet of Windmill Branch and 303 linear feet of an intermittent tributary.

CRI completed a wetland and watercourse delineation at the project site.  The study area consists of approximately 14 acres which includes the mainstem, one intermittent tributary, and adjacent undeveloped riparian areas directly north and south of the streams up to the backyards of the residences that line the stream valley. Wetlands were identified using the USACE Atlantic and Gulf Coastal Plain Regional Supplement.  CRI collected and recorded detailed field data on vegetation, soils, and hydrology for representative wetlands on Wetland Determination Data Forms.  Each wetland was categorized by type (e.g., forested, scrub-shrub, emergent, etc.).  Stream characteristics were recorded for each identified watercourse.  The boundaries of each wetland and watercourse were flagged and each flag was then surveyed using a handheld Trimble GPS unit.  The mainstem of Windmill Branch and one intermittent tributary were traditionally surveyed.  A detailed wetland delineation report was prepared summarizing all identified resources and include datasheets, mapping, and photographs of each resource.

All specimen trees (30-inch or greater diameter at breast height (DBH)) within the study area were identified in addition to trees with a DBH 10-inches and greater located within the critical area.  All trees were tagged and numerically labeled.  The location of each tree was GPS surveyed. 

CRI coordinated with the Maryland Department of Natural Resources (DNR), and the U.S. Fish and Wildlife Service (USFWS) for information on federal and state-listed RTE species and fisheries resources and completed the USFWS Information for Planning and Consultation (IPaC) review process.  Additionally, CRI completed coordination with the Maryland Historic Trust (MHT) and Critical Area Commission for review of the project site.

Location:

Town of Easton, MD 

Client:

Town of Easton, Engineering Department

Key Services:

  • Wetland Delineation 
  • Tree Survey
  • Agency Coordination
  • Stream Restoration Design
  • Geomorphic Assessment
  • BANCS Assessment (BEHI/NBS)
  • Permitting Support and Submittal

CRI also prepared and submitted a Joint Permit Application (JPA) package including impact plates, alternative and impact avoidance/minimization analysis and conducted pre-application agency meetings. In addition to coordinating with MDE and USACE, CRI submitted for an erosion and sediment control permit through the Talbot County SCD. CRI produced Erosion and Sediment Control plans and will revise them based on SCD comments to obtain approval. 

 CRI performed a detailed geomorphic assessment including a longitudinal profile and cross sections, BANCS streambank analysis, site features and mapping for the project. The study documented existing conditions and provided the basis for the concept stream restoration design.  CRI conducted a detailed hydrologic study of the stream and tributary to determine the design discharge based on GISHydro and agreement with the Maryland regression equations and the geomorphic data. CRI developed a HEC RAS 2D model. The results of this model are used to show the stability of the in-stream structures and the water surface elevations for the 2, 10, and 100-year storms. 

CRI produced Concept (15%), Preliminary (30%), and Final Plans (90%) for the City of Easton.  In the future, CRI will finalize the design and provide the City with Signature Plans and a cost estimate for construction. 

The proposed design mimics the stable upstream conditions and applies similar dimension, pattern, and profile to the unstable areas of Windmill Branch. The existing channel width will be widened to increase the channel width to depth ratio. Existing near vertical banks will be graded back to a 3:1 slope or less to decrease bank erosion potential and promote floodplain connection. Channel sinuosity and proposed woody structures will reduce in-channel velocities and shear stress by slowing down the flow and increasing roughness within the channel. Floodplain grading will lower the left floodplain along Windmill Branch to promote left overbank flow and provide flood storage. The intermittent tributary will be regraded to eliminate existing steep drops and provide a more gradual descent to the Windmill Branch confluence. Natural grade controls will stabilize the reach. Floodplain benches are proposed to provide some flood relief within the confined valley.