Water Quality - New stormwater facilities
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New stormwater facilities
Source: WSDOT Environmental Services Office.
Note: Urban areas are defined as areas covered by the municipal stormwater permit, which authorizes WSDOT to discharge stormwater into state waters and sets requirements for pollution reduction.
Performance analysis
FY2023
WSDOT builds 25 new stormwater facilities during fiscal year 2023
WSDOT built 25 stormwater treatment and flow control facilities during fiscal year 2023 (July 2022 through June 2023) to help prevent adverse effects to rivers, lakes and other water bodies (refer to graph below). All facilities were constructed in urban areas of the state and were covered by the agency's municipal stormwater permit.
Of the 25 projects built during the fiscal year, 23 stormwater facilities were components of larger WSDOT transportation projects. Two facilities were components of a stand-alone retrofit project adding treatment for existing impervious surfaces at a prioritized location. The number of new stormwater facilities WSDOT builds each year depends on how many transportation projects are under construction. For example, when WSDOT adds new lanes to a highway, the agency is required to add a stormwater facility such as a biofiltration swale (a vegetated ditch that helps remove pollutants from stormwater before it flows into a river, lake or groundwater).
FY2022
WSDOT builds 88 new stormwater facilities during fiscal year 2022
WSDOT built 88 stormwater treatment and flow control facilities during fiscal year 2022 (July 2021 through June 2022) to help prevent adverse effects to rivers, lakes and other water bodies (refer to graph below). Of the 88 facilities, 83 were constructed in urban areas of the state and were covered by the agency's municipal stormwater permit.
All 88 stormwater facilities were components of larger WSDOT transportation projects. The number of new stormwater facilities WSDOT builds each year depends on how many transportation projects are under construction. For example, when WSDOT adds new lanes to a highway, the agency is required to add a stormwater facility such as a biofiltration swale (a vegetated ditch that helps remove pollutants from stormwater before it flows into a river, lake or groundwater).
FY2021
WSDOT builds 72 new stormwater facilities during FY2021
WSDOT built 72 stormwater treatment and flow control facilities during fiscal year 2021 (July 2020 through June 2021) to help prevent adverse effects to rivers, lakes and other water bodies. Of the 72 facilities, 25 were constructed in urban areas of the state and were covered by the agency's municipal stormwater permit.
All 72 stormwater facilities were components of larger WSDOT transportation projects. The number of new stormwater facilities WSDOT builds each year depends on how many transportation projects are under construction. For example, when WSDOT adds new lanes to a highway, the agency is required to add a stormwater facility such as a biofiltration swale (a vegetated ditch that helps remove pollutants from stormwater before it flows into a river, lake or groundwater).
FY2020
WSDOT builds 106 new stormwater facilities during FY2020
WSDOT built 106 stormwater treatment and flow control facilities during FY2020 (July 2019 through June 2020) to help prevent adverse effects to rivers, lakes and other water bodies. Of the 106 facilities, 20 were constructed in urban areas of the state covered by the agency's municipal stormwater permit.
All 106 stormwater facilities were components of larger WSDOT transportation projects. The number of new stormwater facilities WSDOT builds each year depends on how many transportation projects are under construction. For example, when WSDOT adds new lanes to a highway, the agency is required to add a stormwater facility such as a biofiltration swale (a vegetated ditch that helps remove pollutants from stormwater before it flows into a river, lake or groundwater).
FY2019
WSDOT builds 66 new stormwater facilities during FY2019
WSDOT built 66 stormwater treatment and flow control facilities during FY2019 (July 2018 through June 2019) to help prevent adverse effects to rivers, lakes and other water bodies. Of the 66 facilities, 47 were constructed in urban areas of the state covered by the agency's municipal stormwater permit.
All 66 stormwater facilities were components of larger WSDOT transportation projects. The number of new stormwater facilities WSDOT builds each year depends on how many transportation projects are under construction. For example, when WSDOT adds new lanes to a highway, the agency is required to add a stormwater facility such as a biofiltration swale (a vegetated ditch that helps remove pollutants from stormwater before it flows into a river, lake or groundwater).