Environmental Permitting for Industrial Property Development

  • Wetland on site proposed for industrial development in Pierce County, Washington.
  • Conducting soil characterization for wetland delineation.
  • Documenting white oak for preservation.
  • 2019 drone image taken just after grading for construction of the mitigation site.
  • 2022 drone imagery showing plant growth.

Sierra Pacific Industries (SPI) developed industrial land in Frederickson, Washington. Confluence Environmental Company served as the lead consultant for critical areas studies; wetland mitigation design and planning; environmental review; and local, state, and federal environmental permitting for the property.  Confluence led the multi-disciplinary team from design of site development through design of on-site and off-site critical areas mitigation.


SPI’s goal was to meet required permitting for a 250-acre property proposed for an industrial park. Confluence led the following efforts: preparing State Environmental Policy Act (SEPA) checklists and Joint Aquatic Resources Permit Applications to support the proposed developments; completing submittal of site development documents; preparing critical areas studies; negotiating jurisdictional determinations for on-site wetlands; preparing biological evaluations for compliance with the Endangered Species Act; managing cultural resource studies; developing plans and strategies for critical areas mitigation; managing traffic impact analyses; managing air and noise studies; coordinating with site survey and civil engineering to support project needs for site access and mitigation planning; and coordinating and managing permitting for local, state, and federal permits.

Confluence addressed the impacts of the proposed project on wetlands through development of detailed mitigation plans using the Washington State Department of Ecology’s Credit/Debit tool. As part of the mitigation design, Confluence conducted critical areas studies and permitting on 40 acres of off-site property. Confluence provided construction oversight of the wetland mitigation area and has performed the first 3 years (through 2022) of mitigation monitoring using traditional monitoring methods as well as unmanned aerial systems (drones) to collect color photos and infrared imagery. The infrared imagery is being used to identify distressed vegetation, facilitating adaptive management. In addition, Confluence assisted SPI in identifying and designing off-site mitigation for impacts to Oregon White Oaks, and we have conducted 4 years (through 2022) of Oregon White Oak monitoring.

In a follow-on project for another applicant, Confluence expanded the original mitigation area by 3 acres to provide compensation for unavoidable wetland impacts for an unrelated but adjacent industrial development.


Confluence employed a unified approach to project-development planning and critical areas mitigation resulting in a combination of on-site and off-site mitigation that supports the development of the property and provides a cost-effective and ecologically beneficial solution to a variety of critical areas impacts.

Project Location
Pierce County, Washington

Sierra Pacific Industries and Logistics Property, LLC

Project Timeline
Ongoing since 2013