Environmental guidance for planning studies

Use this guidance to incorporate environmental considerations into planning studies.

The statewide transportation planning process requires transportation agencies to protect and enhance environmental consideration in the planning process (23 CFR 450.206(a)(5)). 

Find guidance regarding Federal Planning and Environmental Linkages (PEL) at the bottom of this page.

For statewide, regional or modal plans, contact the Environmental Service Office’s National/State Environmental Policy Act (NEPA/SEPA) Program to tailor your efforts.

Before you start

Review Environmental Manual Chapter 200: Environmental Considerations in Transportation Planning (PDF 274KB) for application, policy context and legal requirements.

Agency staff can access the suggested environmental data layers through our internal GIS workbench or interactive web mapping applications referenced in each discipline section below. Contact HQ Environmental Services Office Environmental Information Program for assistance with the GIS workbench. 

Environmental screening

Conduct an environmental screening to ensure that environmental context and priorities inform the plan’s practical recommendations. We encourage planners to gather information on the following essential environmental elements.

This level of environmental screening should: 

  • Identify existing environmental assets that must be protected. 
  • Detect other key environmental factors that have the potential to influence the scope of future investments. 
  • Determine if additional environmental review is necessary prior to project development. 

If a planning effort may lead to a defined project, please work with your regional environmental staff to determine the likely environmental classification. Refer to the following guidance and contact the appropriate region or modal environmental manager (PDF 89KB) or our HQ NEPA/SEPA program for assistance with the environmental screening or environmental classification, if working on a defined project.

Note: The following environmental disciplines form an abbreviated list intended for planning studies. Please note that additional disciplines might require consideration at the project level. Each discipline below includes subject matter expert contact information to support planning study development.

Fish passage barriers

We consider fish barrier correction for any future project that alters the roadway prism or adds infrastructure within the existing right of way. The process for determining when to include barrier correction in transportation projects includes protecting and maintaining passable culverts and any previously corrected barriers to ensure water crossing structures remain passable.

Use the ‘Culverts with Fish Use’ layer and the ‘Delivery Plan’ layers in our Fish Passage Inventory Web map to locate fish passage barriers and corrected barriers within or adjacent to the planning study area. You can also view the data in the GIS Workbench.

Use our internal Fish Passage Site Management Application to find site descriptions and project information, determine fish barrier status, generate reports, and view photos of fish passage sites.

Updating fish passage inventories during planning helps identify future funding needs.

GIS workbench layers

Contact the Stream Restoration Program Manager

Web tools

WSDOT Fish Passage Inventory Web Map

Contact

Contact the Stream Restoration program manager to verify information or determine if the fish passage inventory needs an update.

Wetland and other environmental mitigation sites

We construct environmental mitigation sites to compensate for impacts to wetlands and other sensitive areas that cannot be avoided. WSDOT must monitor many of these important assets for 10+ years and protect them in perpetuity.

Use the ‘Environmental Mitigation Sites’ data layer in the GIS Workbench or on the WSDOT Online Map Center to locate WSDOT environmental mitigation sites within the planning study area.

Consider additional wetland information later as project-level information develops using guidance on the Wetlands & other waters webpage.

GIS Workbench Layers

Business Area: Environmental

Wetlands > Environmental Mitigation Sites

Web Tools

WSDOT Online Map Center

WSDOT environmental mitigation sites

Contact

Contact the region or modal environmental manager or Wetland Program Manager to verify information.

Chronic environmental deficiencies (CED)

WSDOT’s CED program identifies locations along state highways where frequent emergency repairs or maintenance activities harm fish habitat. The program was established as an obligation to Washington State Department of Fish and Wildlife (WDFW) to track these sites and implement long term projects that protect state highways, reduce impacts to fish from frequent repairs, and increase the safety and resiliency of state highways.

View the CED webpage to learn more about the program. Use this CED information to propose practical long-term solutions that address active CED sites and protect resolved CED sites.

Contact

Contact WSDOT’s CED Coordinator to determine if there are any CED sites in the planning study area, their nature and status, and any proposed solutions that WSDOT has committed to implementing.

Noise walls

We build and maintains noise walls to reduce the level of road noise and maintain them in perpetuity. We may propose retrofit noise walls in priority areas if funding is available.

Use the ‘Noise Walls, Built’ and ‘Noise Walls, Proposed’ data layer in the GIS Workbench to locate existing and proposed retrofit noise walls within the planning study area.

GIS Workbench Layers

Business Area: Environmental

Transportation Features > Noise Walls, Built

Transportation Features > Noise Walls, Proposed

Contact

Contact the Air Quality, Noise, and Energy Supervisor to verify information.

Historic bridges

We protect and maintain state-owned bridges on, or eligible for, the National Register of Historic Places. We consider other cultural and historic resources as project-level information develops.

Use the ‘WSDOT Historic Bridges’ data layer in the GIS Workbench to locate historic bridges within the planning study area.

GIS Workbench Layers

Business Area: Environmental

Transportation Features > WSDOT Historic Bridges

Contact

Contact WSDOT's Historian to verify information.

Stormwater best management practice (BMP) sites and retrofit priorities

We construct and maintain stormwater BMPs to reduce the impacts of stormwater runoff from paved surfaces. Future projects must protect or replace existing BMPs. Projects that expand impervious surfaces or are within priority retrofit areas may require new BMPs.

Use the ‘Stormwater Features, BMPs’ data layer in the GIS Workbench to locate BMP sites within the planning study area.

GIS Workbench Layers

Business Area: Environmental

Water Quality > Stormwater Data > Stormwater Features, BMPs

Contact

Contact the Stormwater Features Manager to locate any medium or high retrofit priorities within the planning study area and to verify all stormwater information.

Climate vulnerability

We consider climate change and extreme weather impacts.

Use the ‘Climate Vulnerability Assessment’ data layer in the GIS workbench to locate WSDOT assets within the planning study area with medium or high vulnerability to climate threats. Consult with local planning partners to determine availability of additional area-specific climate data.

Use this information to document how climate change and extreme weather vulnerability are considered. Propose practical long-term solutions that improve the resilience of the transportation system in the planning area.

Refer to Guidance for considering impacts of climate change in WSDOT plans (PDF 606KB).

GIS Workbench Layers

Business Area: Environmental

Climate > Climate Vulnerability Assessment

Web tools

WSDOT environmental mitigation sites

Contact

Contact the Environmental Service Office's Climate Mitigation and Adaptation Branch for climate change support.

Air quality

We consider air quality at the planning level to ensure we are addressing federal and local policies. 

Use the layers in the ‘Air Quality’ folder in the GIS Workbench to locate air quality maintenance and nonattainment areas within the planning study area. The Washington State Department of Ecology also publishes a map and table of Washington’s air quality maintenance areas.

GIS Workbench layers

Business Area: Environmental

Air Quality > Carbon Monoxide (Service – ECY)

Air Quality > Particulates (Service – ECY)

Web tools

Washington air quality maintenance areas

Contact

Contact the Air Quality, Noise, and Energy Supervisor to verify information and determine if the project requires an air quality analysis. 

Greenhouse gas emissions 

We prioritize assessing greenhouse gas emissions at the planning level. Reducing Vehicle Miles Travelled (VMT) is a key strategy to reducing transportation sector greenhouse gas emissions and is one of two identified strategies along with electrification in the state’s energy strategy. Planners should identify strategies to reduce VMT and increase other modes of transport such as transit, active transportation, demand and system management, and through strategic land use planning. For operational emissions, if the planning study has detailed annual mileage and travel data available. For construction emissions, follow guidance using FHWA’s Air quality, energy & greenhouse gas emissions ICE tool.

Web tools 

Greenhouse Gas Analysis (ICE Tool)

Detailed Annual Mileage and Travel Data

Contact

Contact the Air Quality, Noise, and Energy Supervisor to determine how a climate change analysis should be completed.

Habitat connectivity

We prioritize opportunities that protect fish, wildlife, and habitat resources, taking a two-pronged approach to addressing wildlife connectivity concerns: 1) efforts intended to increase or maintain the permeability of the landscape to animal movements (increase habitat connectivity), and 2) those that are intended to reduce collisions between wildlife and vehicles along state highways. Early consideration of fish and wildlife habitat connectivity needs increases the likelihood that reasonable approaches to accommodating them can be incorporated into projects.

Use WSDOT’s Habitat Connectivity Investment Priorities to locate any medium or high priority segments for Ecological Stewardship (Eco Rank) or Wildlife-related Safety (Safety Rank) within or adjacent to the planning study area. These can be found by navigating to the ‘Habitat Connectivity – Maximum Rank, Non-Sensitive’ data layer in the GIS Workbench, or by accessing the Fish Passage Inventory Web Map.

If the planning study area includes medium or high priority segments for Ecological Stewardship, contact the Habitat Connectivity SME to discuss their implications. 
If the planning study area includes medium or high priority segments for Wildlife-related Safety, contact the Habitat Connectivity SME to obtain current wildlife carcass removal data for your project. In the data request, please specify the highway(s) and milepost range(s) for your project area.

WSDOT’s Wildlife Carcass Removal Database is the authoritative carcass removal dataset, subjected to a rigorous validation process, and which includes:

  • Wildlife carcass removals reported by WSDOT Maintenance staff.
  • WDFW deer and elk salvage data (this is QA/QC’ed by WSDOT staff and rolled into the Wildlife Carcass Removal Database).
    • The “Source Code” and “Disposal” fields on provided data will indicate source, such as salvaged or WSDOT-reported.
  • Verified wildlife carcass removals reported by external sources that were not included in either WSDOT- or WDFW-reported data.

Use the ‘Pollinator Habitat Rankings’ data layer in the GIS Workbench to locate any medium, high, or very high priority segments for Pollinator Habitat, Urban Gateway Habitat or Monarch Habitat within or adjacent to the planning study area.

Use this information to propose practical solutions for improving habitat connectivity.

GIS Workbench Layers

Business Area: Environmental

Fish and Wildlife > Habitat Connectivity (Non-Sensitive) > Habitat Connectivity – Maximum Rank, Non-Sensitive

Fish and Wildlife > Pollinator Habitat Rankings

Web tools

Data can be accessed within the Fish Passage Inventory Web Map

Other Features > Habitat Connectivity Investment Priorities

Contact

Contact the Habitat Connectivity Biologist to verify information.

Hazardous materials contamination sites

We review known contaminated sites to ensure that those sites do not impact, or become impacted by, future projects.

Use the Washington State Department of Ecology’s Toxics Cleanup Map to locate contaminated sites in the planning study area. Document sites with any of the following statuses:

  • Awaiting cleanup
  • Cleanup started
  • Monitoring cleanup progress

Web tools

Toxics Cleanup Map

Contact

Contact the Hazmat Program Manager to verify information and discuss strategies for addressing contaminated sites in future projects.

Planning and Environmental Linkages (PEL)

Planning and Environmental Linkages (PEL) studies consider environmental, community, and economic goals early in the transportation planning process. This can create more efficient outcomes for project delivery by eliminating duplication of effort between planning studies and the environmental review process. More information on PEL.

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.