Summary

Funding for the assessment of hydrologic modifications and potential designs for a bioswale in Kincaid Ravine will not only help address the issue of flooding on the Burke-Gilman Trail at the edge of Kincaid Ravine, but will also add to the ongoing efforts to restore the habitat and ecological functions of a previously underutilized open space on campus.  The initial assessment will focus on characterizing the quality and quantity of the water moving through Kincaid Ravine.  This will require lab testing for soil and water quality and some hydrologic monitoring and modeling to determine the amount of water moving through the ravine during the wet months.  Once this assessment is complete, the goal is to develop a design for a bioswale in the lower reaches of the ravine that will capture water and filter out sediments and pollutants from flowing into Lake Washington.          

Bioswales are landscape features designed to slow down the flow of surface and storm water runoff.  This process, along with the help of wetland vegetation, allows for the removal of sediment and contaminants.   Currently, Kincaid Ravine has an incised channel that collects surface and storm water and flows quickly toward the edge of the ravine and frequently ends up covering the Burke-Gilman Trail.  A small depressional bioswale could help slow the flow down and remove sediment and pollutants from the water with the help of a diverse planting of native sedges, rushes, grasses and shrubs in and on the edges of the bioswale.  A thorough site assessment and a strong bioswale design are crucial first steps in achieving the goals of restoring and enhancing wetland ecological functions, limiting flooding and providing an opportunity for education due to the Kincaid Ravine’s high visibility near the entrance of campus. 

Environmental Impact

Wetlands are considered the “kidneys” of the landscape due to their excellent ability to store and treat water from contaminated sources.  However, a key component that allows for this ecological function to be beneficial is the amount of time it takes the water to pass through the wetland system, which is called the hydroperiod.  At Kincaid Ravine, storm water flows have created an incised channel that quickly funnels water down from the ravine where it spills out along the the Burke-Gilman Trail.  Slowing down this hydroperiod would allow for more groundwater recharge, sediment deposition, phytoremediation and more diverse wetland habitat for a variety of plant and wildlife species.

Student Leadership

The restoration work at Kincaid Ravine already involves multiple graduate students from the School of Environmental and Forest Sciences, undergraduate classes in the School of Environmental Science and Resource Management and the University of Washington chapter of the Society for Ecological Restoration.  There are regular volunteer work parties held in the ravine and the site will continue to serve as a laboratory for graduate and undergraduate students to work with and study hydrology, soils, habitat restoration and wildlife.  Students in SEFS will continue to lead these opportunities and work to further develop relationships with project partners on campus, such as the UW Transportation Services, UW’s landscape architect and grounds crew and off campus groups such as EarthCorps who have been helping in the restoration efforts in Kincaid Ravine.  A creation of a bioswale will only diversify the opportunities for people and groups to get involved.

Education and Outreach

Restoring the habitat and ecological functions in Kincaid Ravine is a major priority, but one that must go hand in hand with the need to educate people about the importance of these ecological restoration efforts and also let them know how they can get involved or use similar practices to solve environmental problems throughout the region.  The design and creation of a bioswale will only give further opportunity to use Kincaid Ravine as a laboratory and possibly serve as a model of how to create bioswales in urban forests.  The bioswale will give opportunities to study wetland hydrology, soils and the effect plants have on removing pollutants from water and soils.  Kincaid Ravine will also be used to host interpretive signage about the restoration achievements and goals.  The site already has the advantage of high visibility next to the Burke-Gilman Trail and this visibility will be used to make sure that Kincaid Ravine is an example of how to re-establish healthy forest ecosystems.

Feasibility and Sustainability

The need for the site assessment and the development of a bioswale design for Kincaid Ravine is necessary in determining a plan for a project that will fit within the landscape and be sustainable with limited maintenance over a long period of time.  It is important to spend this effort on the assessment and design phase to ensure the bioswale functions properly, limits flooding, is suitable for the average amount of water on site, and matches the goals and objectives from other University of Washington interests.  We have met with and have support from the UW Transportation Services as they continue to work towards an expansion of the Burke-Gilman Trail along Kincaid Ravine and the west side of campus.  Burke-Gilman Trail expansion architect Elisabeth McLaughlin has also expressed interest in incorporating the bioswale into an educational nook along the trail.  The development of a bioswale assessment study also has support from UW Landscape Architect Kristine Kenney, and Grounds Manager Howard Nakase.  We will continue to meet with these groups and other interested parties to achieve consensus on any potential bioswale designs.    

Budget

Water quality testing:  All costs are for samples to be analyzed at the SEFS Research and Analytical Lab at Bloedel Hall.

• Metals - $12.50 per sample X 10 samples = $125
• Carbon - $23.50 per sample X 10 samples = $235
• Soils - $17 per sample X 20 samples = $340
• Sample Prep - $45 per hour X 5 hours = $225

Total Cost: $925

Bioswale Assessment and Design:

• $4,000 for outside consulting on hydrological assessment and bioswale design options. 

Estimated Total Budget: $4,925

*This project is sponsored by Dr. Susan Bolton of the School of Environment and Forest Sciences.