The Chapter 105 Program regulates any water obstructions and encroachments located in, along, across, or projecting into a watercourse, floodway, or body of water, whether temporary or permanent. The obstructions and encroachments may include bridges, culverts, stream enclosures, watercourse, wetland fills, outfalls, utility lines, stream relocation, streambank stabilization, stream restorations, wetland restorations, temporary road crossings, permanent road crossings, docks, and piers.

Why Regulate Streams?

  • Streams are a public resource, including the provision of drinking water and recreation
  • Streams provide ecosystem services, including the management of sediment and nutrients, and moderating the impacts of flooding. A healthy stream reduces water treatment costs and damage to homes, buildings, bridges and roads
  • Streams contain a world of life; countless critters live in or depend on streams to survive
  • Our streams, and the ways that we impact them, do not stop at the borders of Allegheny County. What we do upstream impacts conditions downstream, including nearby neighbors all the way down to the Gulf of Mexico.
  • There are over 2,000 miles of streams in Allegheny County. Streams are a part of our region's beauty and history.