Urban Stormwater Improvements

A two acre parking lot adjacent to a primary arterial was redesigned to make room for 4 large rain gardens, and to increase the planting areas. This resulted in significant impervious surfaces to be removed. Additionally, a large street side area, formerly covered with bark mulch underwent soil improvements followed by dense plantings. This project will manage air pollution as well as the stormwater off of this site, reducing the downstream flooding impact while cleaning and cooling the stormwater. The trees will also provide cooling in the summer, and improve habitat both on site, and in downstream tributaries.

Toxins from urban commercial and industrial sources are listed as primary threats to UWR spring Chinook salmon and steelhead in the UWR Conservation and Recovery Plan for Chinook and Steelhead (1). Eugene is the largest urban impact area on the UWR, and the primary contributor of temperature, heavy metals, petrochemicals, Per and Polyfluoroalkyl Substances (PFAS), and 6-PPD-quinone, all of which are known to significantly impact fish survival. Inputs are typically through stormwater which enters the UWR both directly from urban spaces into the Willamette River, and indirectly through the Long Tom River (via Amazon Creek and its tributaries). Amazon Creek, Fern Ridge Reservoir, and Long Tom River, and UWR are all 303(d) listed streams for a long list of constituents of concern including lead, mercury, dissolved oxygen, temperature, and turbidity (2), all of which are recognized as common urban stormwater pollutants (3).
This project will benefit fish populations by addressing urban pollutants from a large, established church and school where community gathers and education is conducted. The project will be retrofitting an existing parking lot and improving the existing landscape to clean, cool, and delay the stormwater in an effective and aesthetically pleasing way that aligns with the use and priorities of the landowners. In addition to the primary goal of water quality and inherent ecosystem services of green stormwater infrastructure, this site already attracts a high number of people whose interaction with the projects will expand the awareness of the program, the problems that it seeks to resolve, and action that everyone can take to further reduce urban stormwater impacts at their own place of work or at home.
(1) Upper Willamette River Conservation and Recovery Plan for Chinook Salmon and Steelhead, ODFW and NMFS Northwest Region, 2011
(2) Willamette Basin TMDL: Upper Willamette Subbasin, Chapter 10, Table 10.1, p. 6-10, ODEQ September 2006
(3) Water Quality: How Toxic Runoff Affects Pacific Salmon & Steelhead, NOAA Fisheries Service, 2012