WRRC Seminar Series Spring 2015

Location: POST 126, UH Manoa
Time: 3:00 -4:00 PM

**There will be two short presentations on this day.**

Title: An Inventory of Sedimentation in Hawaii’s Reservoirs, Kim Fallinski, PhD Candidate, Department of Tropical Plant and Soil Sciences, CTAHR, UH Manoa

Abstract: Hawaii’s reservoirs face increasing scrutiny due to heightened dam safety and flood control concerns, growing water demands, and uncertain water pollution effects. In order to promote long term reservoir sustainability, it is vital that we improve our understanding of reservoir capacity loss due to sedimentation. We will describe efforts to analyze existing physical data about reservoirs located on the main Hawaiian Islands, and report on the results of interviews with reservoir managers throughout the state about storage capacity and sedimentation processes. Although sedimentation of Hawaii’s reservoirs is rarely measured or documented, we suggest that it is a serious concern, and that the accurate measurement of reservoir sedimentation is a challenge for proper reservoir management. Reservoirs in Hawaii are a significant resource for adaptive and sustainable water supply, conservation, and flood control, and as such the maintenance, including assessment and removal of sediments, are an important consideration for water use and development on each island.

Title: Mitigating the Effects of Urbanization with Bioretention Rain Gardens Amanda Cording, PhD Candidate, Department of Plant and Soil Science, University of Vermont, Burlington, Vermont

Urbanization has had a profound effect on water quality and hydrology of local watersheds as a result of increased stormwater runoff from impervious surfaces. Biological retention, or “bioretention,” is a a best management practice (BMP) for stormwater management to attenuate peak flow and remove some pollutants from the water. The pollutant removal mechanisms in bioretention are complex and often vary with field conditions. In 2012, the University of Vermont constructed an outdoor bioretention laboratory with eight cells receiving water from small road-watersheds on a medium traffic road for more than two years. This presentation will discuss the design, experiment and preliminary results from two years of this study. These results can be also useful in guiding designs for bioretention systems in Hawaii and help mitigate receiving water quality problems.