Options narrowed for safeguarding Lower Green River Valley from flooding

(The Center Square) – A recent meeting of the King County Flood Control District included an update on flood risk and mitigation planning regarding a 21-mile corridor along the Lower Green River at risk of severe flooding.

For homeowners and business owners in the Lower Green River Valley, the biggest takeaway may have been that there are tens of thousands of homeowners and jobs that could be jeopardized in the event of a major flood.

According to the district, some 27,000 residents and the stability of 28,000 jobs are at risk.

The flood district has been conducting studies and taking public feedback as it moves toward a final Programmatic Environmental Impact Statement, or PEIS, with impacted homes and businesses able to see potential risk.

The PEIS looks at costs, impacts and benefits for each of three possible approaches to dealing the potential flooding, including impacts to salmon recovery and the opportunity for additional recreation along the river. A key finding is that all three approaches, or alternatives, substantially reduce flooding in most areas during a major flood.

Part of the planning process included a recent visit by two members of the Flood Control District to Broward County, Fla.

Chair Reagan Dunn, Supervisor Pete von Reichbauer, and others went to the Sunshine State to look for insights into South Florida’s challenges with rising sea levels and intense storms.

Following the visit, Dunn wrote on the King County Flood Control District website, “In the face of climate change, the important work of flood mitigation and resiliency is evolving quickly, with new research, technologies, and methodologies emerging continuously. The King County Flood Control District draws inspiration from the exchange of experiences, successes, and challenges with counterparts across different regions of the country.”

Reichbauer wrote, “By comparing notes, we can cross-pollinate ideas, learn from each other’s approaches, and adapt best practices to our specific contexts.”

During the April 30 King County Flood District Control meeting, members discussed promises made by the Army Corps of Engineers when the Howard Hanson Dam was completed in 1961 to protect river communities.

Major rains and snowmelt strained the dam’s capacity in 2009 after flooding in multiple counties forced federal attention to the issue.

At the time the U.S Corps of Engineers discovered two depressions in the earthen abutment of dam. Fearing catastrophic failure, drastic measures were taken to prepare for a potential loss of the dam: levees were shored up, Sea-Tac Airport put in a redundant electrical system and King County’s Elections was relocated from Renton to Boeing Field, among other emergency protective measures.

The county applied for Federal Emergency Management Agency reimbursement, but after several denials and appeals, FEMA said “applicants do not qualify as eligible emergency protective measures under FEMA’s Public Assistance Program.”

The District Board of Supervisors plant to identify next steps that could include directing the development of a Lower Green River Corridor Flood Hazard Management Plan.