Integration of Urban Stormwater Infrastructure in Modeling Water Quality Patterns in Small Urban Streams
The Issue: Stormwater can quickly run off impervious surfaces delivering potentially polluted water to streams and rivers in the Puget Sound region. Runoff from impervious surfaces can either be directly connected to streams through stormwater pipes or indirectly connected if runoff is routed to some other surface such as grass or a feature like a stormwater management structure. It is currently difficult to map the connectivity of impervious surfaces to streams and assess the impact of stormwater on the water quality of streams.
How USGS will help: The USGS will utilize existing geospatial data to develop land cover metrics that account for stormwater pipe networks and the connectivity of impervious surfaces. Metrics will be developed for two pilot basins in King County, WA, and be tested to evaluate their ability to predict streamflow and water quality patterns within the study basins.
Problem:
Urban development alters hydrology and degrades water quality. These impacts can be particularly pronounced in small urban watersheds with high impervious cover, including those in the Puget Sound region. Stormwater pipe networks can expand or contract the surface stream network depending on local topography and the location and depth of pipe networks. However, the current state of science rarely accounts for variability in the connectivity of stormwater infrastructure and impervious surfaces.
Objectives:
This project will build upon previous stormwater studies and lessons learned in the Puget Sound region to develop workflows to create metrics that account for subsurface stormwater infrastructure and the connectivity of impervious surfaces. The metrics will then be tested in models to assess their ability to predict streamflow and water quality patterns in two basins within King County, WA.
Relevance and Benefits:
The proposed work is a critical step in filling an information gap related to the effect of stormwater infrastructure on water quality conditions. This work may inform more efficient implementation of best management practices, target capital improvement projects, and focus recovery of human and ecosystem health. Further, this project is expected to serve as an example of how to scale approaches to a particular basin which may be applied to other urban watersheds within the larger Puget Sound region. Without this work, there will be a continued limited understanding of the influence of stormwater infrastructure on water quality conditions.
Approach:
This work will utilize existing geospatial, water quality, and streamflow data in two basins in King County, WA. The work will:
- Develop one database of streamflow and several water-quality parameters within the selected basins.
- Develop one reproducible database to integrate subsurface stormwater pipe networks into watershed delineation methods and one reproducible workflow to weight impervious surfaces based on potential connectivity to surface-water features.
- Develop one comparative model that integrates existing water quantity/quality data, land cover characteristics, and stormwater infrastructure connectivity to predict water quality constituents and/or streamflow in the selected basins.
The Issue: Stormwater can quickly run off impervious surfaces delivering potentially polluted water to streams and rivers in the Puget Sound region. Runoff from impervious surfaces can either be directly connected to streams through stormwater pipes or indirectly connected if runoff is routed to some other surface such as grass or a feature like a stormwater management structure. It is currently difficult to map the connectivity of impervious surfaces to streams and assess the impact of stormwater on the water quality of streams.
How USGS will help: The USGS will utilize existing geospatial data to develop land cover metrics that account for stormwater pipe networks and the connectivity of impervious surfaces. Metrics will be developed for two pilot basins in King County, WA, and be tested to evaluate their ability to predict streamflow and water quality patterns within the study basins.
Problem:
Urban development alters hydrology and degrades water quality. These impacts can be particularly pronounced in small urban watersheds with high impervious cover, including those in the Puget Sound region. Stormwater pipe networks can expand or contract the surface stream network depending on local topography and the location and depth of pipe networks. However, the current state of science rarely accounts for variability in the connectivity of stormwater infrastructure and impervious surfaces.
Objectives:
This project will build upon previous stormwater studies and lessons learned in the Puget Sound region to develop workflows to create metrics that account for subsurface stormwater infrastructure and the connectivity of impervious surfaces. The metrics will then be tested in models to assess their ability to predict streamflow and water quality patterns in two basins within King County, WA.
Relevance and Benefits:
The proposed work is a critical step in filling an information gap related to the effect of stormwater infrastructure on water quality conditions. This work may inform more efficient implementation of best management practices, target capital improvement projects, and focus recovery of human and ecosystem health. Further, this project is expected to serve as an example of how to scale approaches to a particular basin which may be applied to other urban watersheds within the larger Puget Sound region. Without this work, there will be a continued limited understanding of the influence of stormwater infrastructure on water quality conditions.
Approach:
This work will utilize existing geospatial, water quality, and streamflow data in two basins in King County, WA. The work will:
- Develop one database of streamflow and several water-quality parameters within the selected basins.
- Develop one reproducible database to integrate subsurface stormwater pipe networks into watershed delineation methods and one reproducible workflow to weight impervious surfaces based on potential connectivity to surface-water features.
- Develop one comparative model that integrates existing water quantity/quality data, land cover characteristics, and stormwater infrastructure connectivity to predict water quality constituents and/or streamflow in the selected basins.