Public scoping comments
For NEPA EA’s and EIS’s, 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.
Cumulative effects analysis process
The scope of the cumulative effects analysis should be limited to those resources that are directly or indirectly affected by the proposed action. If your project does not have a direct or indirect effect on a resource, then it cannot contribute to a cumulative effect on that resource. The one exception to this is climate change (see below).
To avoid confusion when designing your analysis, we advise the consistent use of the phrase: “the project’s contribution to cumulative effects on [resource].”
WSDOT projects are strongly advised to follow the guidance in AASHTO Practitioner's Handbook 12: Assessing Indirect Effects and Cumulative Impacts Under NEPA (PDF 1.5MB).
Analysts compile information on trends for each resource before establishing a list of reasonably foreseeable future projects. Assess whether any direct or indirect effects from the project, combined with what we know about the future, will change the trend. This change may be either positive or negative, short-term or long-term. Document the project’s contribution to cumulative effects. Also document potential climate change effects (see below).
The NEPA project lead determines the appropriate method for documenting cumulative impacts. Options include:
- Prepare a separate chapter or section on cumulative effects.
- Integrate the disclosure of cumulative effects within each of the affected resource chapters or sections.
Climate Change and Project Resilience
It is our policy that we discuss climate change in our major environmental documents for state transportation projects. Follow the Guidance for project-level climate change evaluation (PDF 1.6MB) to address the effects of climate change on your project and document those considerations in the project’s environmental document. For EAs and EISs, WSDOT’s policy is to document climate change resiliency considerations in the cumulative effects section. Depending on the project, you may want to address future climate conditions in additional sections, for example: Stormwater or floodplains if future flooding is a concern or 'Geology and soils' if the project’s landslide risk may be exacerbated by drought, fire, or intense rainfall. Document your results in the cumulative effects and climate change section. Supporting documentation can be compiled into a technical memo.
Information on completing project level greenhouse gas evaluations is available on our Air quality, greenhouse gas and energy webpage. The greenhouse gas emissions are typically documented with the air quality and greenhouse gas section, although in some cases they are summarized in the climate change section as well.
Project final design may involve steps to ensure the resilience of the transportation facility. For information on addressing climate resilience in hydraulics work, see the Hydraulics Manual.