Wetlands Protection

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).

2018

• WSDOT added nine new wetland and stream mitigation sites on 17 acres in 2018, bringing the total to 300 sites on 1,623 acres
• WSDOT closed out two mitigation sites on 0.65 acres at the end of their 10-year monitoring periods
• From 2001 through 2018, the number of WSDOT-monitored wetland and stream mitigation sites increased by 135% (54 to 127) and total acreage monitored increased by 468% (213 to 1,209)
• WSDOT's mitigation banks earned 7.42 credits and provided agency transportation projects 0.89 credits in 2018