A new, comprehensive levee database will help Oregon's communities reduce flood risks and plan ecological restoration efforts.
Released on June 27 by the Oregon Department of Geology and Mineral Industries (DOGAMI), the database is a compilation of new and existing levee information for western Oregon -- an area of the state with significant flood hazards. Almost 2,000 miles of levees were identified that may stop or divert water during flooding.
"Knowing where levees are and what land they're protecting helps assess and reduce flood risks," says Fletcher O'Brien, DOGAMI geospatial analyst. "It's also critical information for emergency response during floods."
Flooding is a widespread, common hazard for Oregon. More than 251 communities across the state, including locations in every county, are flood prone. National Flood Insurance claim payments in Oregon totaled $5.8 million from October 2015 through September 2016, according to FEMA statistics.
Clatskanie and the surrounding communities last experienced heavy floods in February. One of the most devastating in the community took place in the summer of 1996.
"Oregon didn't previously have a single comprehensive inventory that maps levees with the high spatial accuracy needed for flood mitigation and response efforts," says Jed Roberts, DOGAMI's flood mapping coordinator.
New levee data was also created. Using aerial images and lidar, which provides accurate high-resolution images of the earth's surface, floodplains, river valleys and other likely levee locations were analyzed. Information about 472 miles of previously undocumented levee features is now available.
Levee information also helps in the planning of environmental restoration projects by highlighting potential opportunities to create habitat through levee removal or modification projects.
"From prioritizing areas for future fish habitat to planning for future research on levee conditions, the benefits of easy access to compiled levee data are many," says O'Brien. "Increased understanding of flood risks also reminds us that as Oregonians, we all need to be prepared for this common hazard."
DOGAMI Open-File Report O-17-02, Statewide Levee Database for Oregon, release 1.0: Major Agricultural and Urban Areas in Western Oregon and along the Columbia River, by Fletcher E. O'Brien includes a geodatabase and report. Download the publication at http://bit.ly/oregonlevees
Funding for the project was provided by the U.S. Army Corps of Engineers, Portland District and the Oregon Geospatial Enterprise Office.