Record Details
Field | Value |
---|---|
Title | Shoreline erosion on Sauvie Island, Oregon: perceptions and management practices |
Names |
Long, Season
(creator) Chan, Smauel S. (advisor) |
Date Issued | 2007-06-18 (iso8601) |
Note | Master of Science (M.S.) |
Abstract | Sauvie Island lies at the confluence of the Columbia River and the Willamette River near Portland, Oregon. Flooding, erosion, and deposition of sediments have been part of the natural evolution of the island. However, with the construction of multiple dams in the Columbia River Basin, levees, and hardening of upstream banks, many natural river processes have been altered, resulting in increased erosion along the Island's shores. The objectives of this project were to, (i) characterize shoreline erosion as perceived by waterfront landowners on Sauvie Island, (ii) determine the role of government agencies in shoreline erosion management, (iii) to "ground truth" property owner and agency perceptions of recent erosion problems, and (iv) to communicate project findings to all parties. The research involved surveying shoreline property owners, interviewing relevant government agency staff to determine their roles and responsibilities for erosion management, and the use of aerial and orthophotos to verify erosion "hot spots". The main findings of this study were that: 1) Columbia River residents are the most concerned about bank erosion, with nearly 25 percent of the respondents losing bank along the entire length of their property; 2) nearly half of the Columbia River respondents have installed some form of bank protection along their waterfront, however, only 25 percent believe that their revetment strategy has prevented further erosion; 3) aerial photo analysis revealed section of the Columbia River shoreline having (accumulative) erosion of up to 5 feet per year; 4) current regulatory jurisdiction for erosion monitoring and control along Sauvie Island is disjointed with no single agency responsible for the monitoring, permitting, and technical assistance landowner's need when installing revetment work. An intended outcome of this project is to encourage cooperative management of shoreline erosion by building understanding of the nature of shoreline erosion on Sauvie Island and to facilitate communication between landowners and government agencies regarding extent, management and mitigation. |
Genre | Research Paper |
Identifier | http://hdl.handle.net/1957/30162 |