Specializing in Wetland Delineation & Mitigation for Single Family Developments

Pacific Willow Consulting Wetland delineation and mitigation - Washington State

What is a Wetland Delineation?

  • If you need to have a Wetland Review conducted on your property, a consultant first will need to make a site visit to gather field information about the topography, soils and vegetation. From this, a determination can be made as to whether or not any wetlands are present.
  • If all three wetland characteristics are present in an area, the boundary of the wetland will need to be established and then marked or delineated with flagging or flagged stakes.
  • Next the flagging points will need to be located in the field relative to the property boundaries so that a Wetland Delineation Map or Site Plan can be created. The wetland points can be mapped by either using a compass and measuring tape (single family properties only), GPS mapping equipment or a surveyor.
  • Following this, the wetland will be rated using the Department of Ecology Rating System (2004 version http://www.ecy.wa.gov/pubs/0406025.pdf, 1993 version http://www.ecy.wa.gov/pubs/93074.pdf) to determine the quality of the wetland. Depending on which category it is, either a I (high class), II, III or IV (low class), and/or what the water quality and habitat values are, this will determine the width of the required protective buffer. All development must stay outside of this buffer unless mitigation measures are offered.
  • The last thing a consultant will do is put together a Wetland Delineation Report, to be presented to city or county officials, that summarizes the site, the scientific field data, the wetland and its rating, and which includes a detailed site map of the existing and proposed development, and any wetlands and their associated buffers.

Wetland delineation plan


  Pacific Willow Consulting Inc, P.O. Box 596, Rainier, Washington 98576
Phone: (360) 458-7463