Wetlands Protection
Highlights
2023
- WSDOT began monitoring three new compensatory mitigation sites on 2.04 acres in 2023
- WSDOT completed monitoring work at 10 mitigation sites on 240 acres at the end of their final-year monitoring periods in 2023
- From 2003 through 2023, the number of WSDOT-monitored compensatory mitigation sites increased from 59 to 87 (47%) and total acreage increased from 360 to 918 (155%)
- WSDOT's mitigation banks provided 2.54 credits to agency transportation projects in 2023
2022
- WSDOT began monitoring two new mitigation sites on 6.97 acres in 2022
- WSDOT completed monitoring work at 13 compensatory mitigation sites on 114.79 acres, which were at the end of their final-year monitoring periods in 2022
- From 2003 through 2022, the number of WSDOT-monitored compensatory mitigation sites increased from 59 to 94 (59%) and total acreage increased from 360 to 959 (166%)
- WSDOT's mitigation banks did not earn or debit (use) any credits in 2022
2021
- WSDOT began monitoring nine new wetland and stream mitigation sites on 32.7 acres in 2021
- WSDOT completed monitoring work at six mitigation sites on 11.48 acres that were at the end of their final-year monitoring periods in 2021
- From 2002 through 2021, the number of WSDOT-monitored mitigation sites increased from 53 to 107 (102%) and total acreage increased from 174 to 1,043 (499%)
- WSDOT's mitigation banks earned 0.20 credits and debited 0.22 credits in 2021
2020
- WSDOT began monitoring six new wetland and stream mitigation sites on 14.39 acres in 2020
- WSDOT completed monitoring work at seven mitigation sites on 10.11 acres that were at the end of their 10-year monitoring periods
- From 2001 through 2020, the number of WSDOT-monitored mitigation sites increased from 54 to 112 (107%) and total acreage increased from 213 to 1,062 (399%)
- WSDOT's mitigation banks earned 0.55 credits and provided 3.98 credits to agency transportation projects in 2020
2019
- WSDOT added six new wetland and stream mitigation sites on eight acres in 2019, bringing the total to 306 sites on 1,631 acres
- WSDOT completed monitoring work at six mitigation sites on 64.4 acres at the end of their 10-year monitoring periods
- From 2001 through 2019, the number of WSDOT-monitored compensation sites increased by 141% (54 to 130) and total acreage increased by 467% (213 to 1,208)
- WSDOT's mitigation banks earned 2.86 credits and provided agency transportation projects 0.12 credits in 2019
WSDOT evaluates noise for two project types
- Type 1 projects involve new construction projects which could potentially increase traffic noise for nearby residents.
- Type 2 projects are retrofits for existing high-traffic roadways near residential areas that were constructed before 1976—the first year that noise evaluations were required for highway projects. WSDOT maintains a prioritized list of eligible Type 2 projects to be considered for construction by the Legislature.
For both types of projects, WSDOT evaluates how it can cost-effectively reduce noise and seeks input from affected communities before taking any noise-reducing action (like constructing a noise wall).
How mitigation banks work for WSDOT
Guidance from the Environmental Protection Agency and the U.S. Army Corps of Engineers' on compensatory mitigation for construction projects recommends mitigation banking. Mitigation banking is like a savings account for WSDOT's future capital projects and mitigation needs. These banks create credits based on the number of acres and their environmental value. Credits can be withdrawn from the account (or used) by projects as compensation for unavoidable wetland impacts within the bank's specified service area.