prairie habitat assessment methodology coverPrairie Habitat Assessment Methodology Protocol

Protocol Document, Version 1.0

The Prairie Habitat Assessment Methodology is a tool to help standardize a method for mitigating impacts to prairie ecosystems through Thurston County’s (County) Critical Areas Ordinance (CAO).

The intention is that this Methodology will be used as part of an Interim Permitting Strategy and, potentially with adjustments, the Habitat Conservation Plan (HCP) for the County. The Methodology may also be adapted by other jurisdictions for mitigating impacts to prairie ecosystems and prairie-associated species. Version 1.0 of the Methodology addresses the following
target prairie-associated species:

  • Streaked horned lark (SHL);
    Eremophila alpestris strigata
  • Taylor’s checkerspot butterfly (TCB); and
    Euphydryas editha taylori
  • Mazama pocket gopher (MPG).
    Thomomys mazama yelmensis, T.m. glacialis, T.m. tumuli, and T.m. pugetensis

The Methodology can accommodate the inclusion of additional target prairie-associated species over time but will maintain its focus on overall prairie ecosystem function. The best available science on plant and animal species biology and ecosystem function is incorporated into the Methodology, producing an estimate of the number of weighted acres of Potentially Suitable

The best available science on plant and animal species biology and ecosystem function are incorporated into the Methodology, producing an estimate of the number of weighted acres of Potentially Suitable Habitat or Potentially Affected Habitat. These numbers represent both the area and quality of prairie being impacted or conserved on project sites in Thurston County. To use these numbers in a mitigation program, there needs to be a way to turn Potentially Affected Habitat into “debits” and Potentially Suitable Habitat into “credits.” This Protocol document describes the rules, processes, and decisions for quantifying debits and credits in a way that should provide certainty and transparency that approved actions on the ground are moving toward the recovery of prairie ecosystems and prairie-associated
species.

The Protocol sections are organized to provide information for specific audiences:

  • Permittees: Permit applicants to the County generating debits;
  • Credit Developers: Individuals or groups generating credits as mitigation for prairie impacts; and
  • Program Administrators: The County and others operating the debit and credit program.

See the full Prairie Habitat Assessment Methodology Protocol.