Montgomery County Department of Environmental Protection (DEP)

Key Services

  • Stream Corridor Assessments
  • Stream Infrastructure, Environmental Inventory, and Habitat Assessment
  • Stream Restoration Concept Design
  • GIS Data Processing

Project Details

The objective of this project was to update the previously completed watershed assessments in the Cabin John watershed and identify priority sites for restoration or improvement. CRI assisted the prime engineering consultant in identifying, prioritizing, ranking, and developing conceptual stream restoration designs.

This study was guided by a modified version of the Stream Corridor Assessment (SCA) protocol developed by Maryland Department of Natural Resources (DNR). The environmental condition information was updated, and desktop and field investigations were conducted to identify potential restoration opportunities.  Stream miles chosen for investigation prioritized areas with high restoration potential (e.g. streams near large untreated parking lots) and were closely coordinated with past and ongoing restoration efforts.

CRI performed field assessments for 20 miles of streams in 3 sub-watersheds using Fulcrum software application field forms to record features such as erosion, pipe outfalls, inadequate riparian buffers, bank erosion, fish blockages, channelized stream sections, exposed utility pipes, unusual conditions, trash dumping, and active construction near the stream. Recorded features were rated for severity, restoration potential, and accessibility so that potential restoration projects could be prioritized. Additionally, in-stream and near-stream habitat conditions were assessed at representative sites spaced at ¼-½ mile intervals along each stream reach. Sites were rated for ten parameters including, but not limited to, shelter for fish, velocity/depth of flow, and bank vegetation. Channel dimensions and bottom sediment type were also recorded. Field investigation results were used to prioritize potential projects using a scoring and ranking system that reflected county priorities, was conducive to implementation planning, and met the goals and objectives of the resource model tool. Additional factors for project scoring included access, pollutant load reductions (TN, TP, and TSS), cost, and impervious cover treated.