Cumulative effects & climate change

Use this information to prepare cumulative impacts analyses for projects requiring an Environmental Assessment (EA) or an Environmental Impact Statement (EIS).

Public scoping comments

For NEPA EAs and EISs, the project team should examine comments submitted during public scoping. Any effects that do not tie directly to project impacts but may impact resources that are also affected by the project, should be addressed in the cumulative effects section. Keep in mind, effects that tie directly to the proposed project are evaluated as direct impacts.

Identify prior studies that can inform your project-level analysis

Determine if a planning level study was completed for the project area. This may be a locally developed plan or a WSDOT corridor study. Environmental Manual Chapter 200: Environmental considerations in transportation planning (PDF 274KB) explains how planning projects (any pre-NEPA plan) can consider environmental issues. If WSDOT conducted a planning effort, look to see if that study examined land use trends, or if it contains a summary of climate change vulnerability identified for the corridor. Guidance for considering effects of climate change in WSDOT plans (PDF 606KB) – this document provides direction on considering climate change impacts during the transportation planning process.

Identify any local or regional transportation plans, Growth Management Act comprehensive plans, climate change resilience plans, and natural hazard mitigation plans that relate to the project area.

166,800 electric vehicle

registrations in Washington in 2023, up from 114,600 in 2022.

87 wetland compensation sites

actively monitored on 918 acres in 2023.

25,000 safe animal crossings

in the Snoqualmie Pass East Project area since 2014.