Session Title

Session S-05E: Managing Floodplain Rehabilitation Success to Inform Decision Making: A Case Study from Hansen Creek, Skagit County

Conference Track

Habitat

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Start Date

1-5-2014 10:30 AM

End Date

1-5-2014 12:00 PM

Abstract

Since 1955, Skagit County has been involved in flooding and sediment issues concerning Hansen Creek. Some form of sediment removal has been the response to localized flooding in the lower portion of the Hansen Creek Watershed. In 1982, at the request of flooded landowners, a Sub-Flood Control Zone was formed. Skagit County will present data on the costs of maintenance dredging and responding to emergency flooding over the 1997-2007 10-year period and also savings to both the County and landowners from the time when the floodplain project was implemented. Since the completion of the Hansen Creek Alluvial fan project in 2010 there has been no expenditure of County assessment funds toward on-the-ground Hansen Creek flood control or channel maintenance. In 2010 the Hansen Creek Sub-Flood Control Zone was abolished mainly due to the establishment and success of the Hansen Creek alluvial fan. The success of the Hansen Creek alluvial fan project in attenuating the amount of sediment delivered downstream and in reducing the frequency, height, and duration of downstream flooding has resulted in collaboration between downstream landowners, Skagit County, and the Skagit River System Cooperative to develop additional floodplain rehabilitation. This downstream reach of Hansen Creek is currently a plane bed channel isolated from its floodplain by berms. The channel is almost entirely straightened and is devoid of any instream features (i.e. woody debris, boulders). Skagit County will highlight, based on the 2002 Hansen Creek Watershed Management Plan, the actions and modeling recommendations being advanced to further mitigate flood impacts in the lower Hansen Creek Watershed and restore natural resource benefits to the ecosystem.

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Language

English

Format

application/pdf

Type

Text

Share

COinS
 
May 1st, 10:30 AM May 1st, 12:00 PM

$aving with Fish, Floodplains & Farmers: Expanding the Reach

Room 613-614

Since 1955, Skagit County has been involved in flooding and sediment issues concerning Hansen Creek. Some form of sediment removal has been the response to localized flooding in the lower portion of the Hansen Creek Watershed. In 1982, at the request of flooded landowners, a Sub-Flood Control Zone was formed. Skagit County will present data on the costs of maintenance dredging and responding to emergency flooding over the 1997-2007 10-year period and also savings to both the County and landowners from the time when the floodplain project was implemented. Since the completion of the Hansen Creek Alluvial fan project in 2010 there has been no expenditure of County assessment funds toward on-the-ground Hansen Creek flood control or channel maintenance. In 2010 the Hansen Creek Sub-Flood Control Zone was abolished mainly due to the establishment and success of the Hansen Creek alluvial fan. The success of the Hansen Creek alluvial fan project in attenuating the amount of sediment delivered downstream and in reducing the frequency, height, and duration of downstream flooding has resulted in collaboration between downstream landowners, Skagit County, and the Skagit River System Cooperative to develop additional floodplain rehabilitation. This downstream reach of Hansen Creek is currently a plane bed channel isolated from its floodplain by berms. The channel is almost entirely straightened and is devoid of any instream features (i.e. woody debris, boulders). Skagit County will highlight, based on the 2002 Hansen Creek Watershed Management Plan, the actions and modeling recommendations being advanced to further mitigate flood impacts in the lower Hansen Creek Watershed and restore natural resource benefits to the ecosystem.