Shifting river, national policy changes community’s role

A trio of photographs depicts the devastation of the 1964 Christmas Day flood on the upper Sandy River Basin on the western slope of Mount Hood, Oregon.  (Photos courtesy of Mount Hood National Forest)

A trio of photographs depicts the devastation of the 1964 Christmas Day flood on the upper Sandy River Basin on the western slope of Mount Hood, Oregon. (Photos courtesy of Mount Hood National Forest)

By Amy Echols, Public Affairs Office

A few weeks after the statewide flood of 1964, the U.S. Army Corps of Engineers began work to “put the (Sandy) river back in the channel it was in prior to the Christmas flood.” Clackamas County commissioners asked property owners on the western slopes of Mount Hood, along U.S. Highway 26 from Brightwood past Rhododendron, to allow the Corps on their properties to tackle flood recovery efforts with bulldozers and backhoes, manipulating river channels and moving massive accumulations of debris.

“The Sandy River in 1964, as in many floods preceding it, scoured a new river channel, leaving communities with losses to public infrastructure and private property,” said Julie Amman, Portland District’s floodplain services manager. “In a basin like the Sandy, composed of unstable volcanic deposits from Mount Hood and steep slopes that produce fast river currents, the river’s course is unpredictable.”

This means that controlling floods using heavily engineered riverbank stabilization will only work for awhile, especially in dynamic river systems like the Sandy. The U.S. Army Corps of Engineers‘ embankment work back in 1965 helped reduced flood impacts for a few decades but came with costs to the environment and proved no match for the large rain and flood events in 1996, 2006 and 2011.

During the flood of 2011, as in 1964, utilities, roads and structures along the Sandy, Zigzag and Salmon rivers, and their tributaries, suffered extensive erosion and damage. The Corps’ approach to recovery in 2011 was very different from that of 1964: the agency sent in no bulldozers and realigned no stream banks.

Portland District used a specific tool to assist the upper Sandy River communities with recovery: issuance of a regional general permit under its regulatory authority. This permit allows specific repairs, reconstruction or restoration activities by property owners themselves. Representatives from Clackamas County and state and federal agencies participated in many local discussions with property owners to support applying for these permits on their own.

This regional permitting approach ensures that property owners’ needs are balanced with those of the community, ensuring cumulative actions up and down the river are minimized. Simply put, the action a homeowner takes to recover a portion of the stream bank cannot impact property or public infrastructure downstream. Compared to individual permit processes, a regional general permit also ensures compliance with federal and state laws, reduces paperwork and saves time.

In addition, the Corps’ national Flood Risk Management Program in 2009 formally shifted flood responses from highly-engineered solutions to using a variety of strategies to reduce risks before a flood. Ammann said the Corps no longer works to manipulate the land at the expense of the environment or to the magnitude seen in past decades.

“In an era when highly-engineered recovery work is a remote option for the Corps, reducing flood risks in vulnerable and dynamic river basins takes a collaborative effort. This requires property owners, residents, communities and all levels of government to understand their roles and responsibilities in reducing risks – ideally in advance of actual flooding,” Ammann explained. In her position with the Corps, Ammann reminds state and local governments of their authority and responsibility to determine how to use land in floodplains and to enforce “flood-wise” requirements.

A different scene

A different scene
emerged as the unpredictable Sandy River jumped its banks, and scoured a new river channel in January 2011,
undercutting homes and wreaking havoc. The Corps and other agencies worked with homeowners on a permitting
process to aid recovery.

Today, Clackamas County’s Emergency Management Office is leading a collaborative effort to turn this challenge into an opportunity, with the formation of a community-based flood risk management work group among the upper Sandy River communities. This effort could integrate environmental, social and economic factors involved in reducing flood risk and consider all available tools and information to improve public safety in the area.

“The future of the upper Sandy River basin depends on stakeholders working together to ensure everyone is informed about the erosion hazards the river poses and the actions they can take to reduce their risks,” said Jay Wilson, the county’s hazard mitigation coordinator and lead planner for this project. “Our hope is that alongside residents and property owners in the basin, the county can better understand the short and long-term implications of land use on floods and reduce risks while fostering a more sustainable relationship with the river.

”The Corps is supporting this community’s efforts to reduce flood risk by providing technical, regulatory and public involvement experience to the county’s call for local and collaborative action.

Wilson and Ammann remind the upper Sandy River communities that even new flood studies, using modern surveying and mapping technology, cannot accurately predict the Sandy River’s course during the next flood. They preach the best defense for these conditions, be they in the shadow of Mount Hood or the flatland of the Willamette Valley: prepare for flooding and strive to reduce long-term risks now.

Corps facilitates Sandy River flood risk discussions

Property owners and residents attend the 2013 Flood of Information outreach event to learn more about the hydrology and other characteristics of the erratic Sandy River and the roles and responsibilities of communities and government in reducing flood risks. (Photo courtesy of Clackamas County, Oregon)

Property owners and residents attend the 2013 Flood of Information outreach event to learn more about the hydrology and other characteristics of the erratic Sandy River and the roles and responsibilities of communities and government in reducing flood risks. (Photo courtesy of Clackamas County, Oregon)

The Corps’ Conflict Resolution and Public Participation Center of Expertise is facilitating collaboration between residents and property owners in the upper Sandy River basin and local, state and federal agencies to increase awareness and decrease flood risks. The Center’s Seth Cohen, in consultation with Clackamas County and Portland District, is guiding community-level discussions of flood hazard issues, increased awareness and the future of the local work group.

The Corps’ national Public Involvement in Flood Risk Management Pilot Program funds Cohen’s support.Cohen and Clackamas County’s Jay Wilson convened and facilitated several meetings in the last year to open two-way communication with the appropriate local, state and federal agencies who also are working in the Sandy River watershed. Participants share information about resources and mitigation actions affecting the upper Sandy River communities. This includes progress on the development of flood insurance rate maps and a channel migration zone analysis and the installation of five new flood gauges.

The Oregon Silver Jackets program initiated this collaborative community approach. Oregon Silver Jackets is a multiagency team consisting of federal and state partners seeking to leverage agency roles and funding to develop more comprehensive flood risk management solutions in Oregon.