Decoration Image:Apples

Shaw Creek Flood Mitigation Project

 

Objectives

The objective of this project is to reduce predicted flooding damage in an area that has been rapidly urbanized on the west side of Yakima.  The NEPA (National Environmental Policy Act) preferred alternative is a total relocation of Shaw Creek.  The second alternative considered is the construction of a bypass channel for major flood events.  This project has been identified in the Ahtanum-Wide Hollow Comprehensive Flood Hazard Management Plan as one of the four major flooding problems of this drainage and the highest priority short term action. The partners involved in the project include FEMA, (Federal Emergency Management Agency), Washington State Emergency Management Division (EMD), Yakima County Water Resources Division, and the City of Yakima.

Project Area Map
Project Area Map

 

Project History and Background


Dense development has modified this area from one of agricultural use years ago to a dense residential area with few remaining open parcels.  Floodplain maps from 1974 did not include this area in the mapping project (this area is currently being remapped with FEMA and Washington State Department of Ecology assistance). There are few remaining areas available to re-locate Shaw Creek or a bypass channel and the proposed location is on property that is undeveloped at this time.

Shaw Creek is a tributary to Wide Hollow Creek and ultimately contributes flood flows to Wide Hollow Creek. The section of Wide Hollow Creek from the road crossings at South 80th Avenue and South 72nd Avenue has had historical flooding problems due to constrictions in the channel and at the bridge. The project will insure capacity for events up to the 100-year flood event for Shaw Creek, protecting several developments including Cottonwood Grove, Clinton Way & Westbrook Additions. Given that development pressure in this area is high, continued development pressure will likely remove the option of a relocation of Shaw Creek or construction of a bypass channel for Shaw Creek. The proposed mitigation project will remove a large area out of the floodplain and floodway and will protect existing residential developments from flooding.

Washington State Department of Fish and Wildlife has recently requested that a relocation of Shaw Creek would be preferable to a bypass channel construction.  A new relocation of Shaw Creek would improve water quality and fish life habitat in Wide Hollow Creek, as a result of a healthier Shaw Creek location. The present location of Shaw Creek just south and parallel to Tieton Drive and south along South 80th Avenue is as a result of a relocation of Shaw Creek many years ago to facilitate irrigation of the area. The physical difference between a Shaw Creek “relocation” concept and a “bypass channel” concept is minimal; the alignment is nearly the same, but there will be additional natural vegetation within the Shaw Creek relocation, and it will include a bifurcated channel at the bottom end. These alternatives will be evaluated in the Environment Assessment process.

In 2008, the public involvement process for this flood mitigation project was initiated with 2 public meetings held on June 9th and 10th at the Cottonwood Junior High School to share flood mapping information, develop alternatives, and gather citizen input and comments.
Following the public meetings in 2008, Yakima County submitted an HMGP (Hazard Mitigation Grant Program) grant request to FEMA (Federal Emergency Management Agency) and the Washington State Emergency Management Division to address these flooding problems, but the grant proposal was rejected due to insufficient data.

In 2010, Yakima County submitted a PDM (Pre Disaster Mitigation) grant request for flooding in this area, and this grant proposal was also rejected for the above-mentioned reasons.

In 2011, Yakima County again submitted a PDM grant proposal to FEMA for funding of the same project, but Yakima County had collected additional survey information on depths of flooding for specific houses which allowed an improved grant proposal and a more accurate benefit cost analysis.

In early 2012, FEMA approved the project for funding, contingent on completing the necessary environmental requirements, and selecting a preferred alternative during the NEPA process. To date, no funds have been released from FEMA, pending meeting the above mentioned requirements. The Environmental Assessment process or NEPA process is in the very initial stages and the cultural resource survey is nearly complete. The Environmental Assessment and Cultural Resource survey has been contracted to URS Corporation.  In addition, a hydraulic analysis and preliminary design is now being completed by West Consultants Inc.  As part of the Environmental Assessment process, public meetings will be scheduled this fall or winter to allow public comments and input. Mailings to all residents in the immediate area will occur prior to the public meetings.

In 2012 and 2013, representatives from Yakima County Water Resources Division have been contacting landowners in the project area to discuss the project and their willingness to sell either an easement or a portion of their land for the Shaw Creek relocation.  The PDM grant provides funding for purchases at a fair market value from willing sellers and condemnation is not permitted in this granting process. Additional meetings with individual landowners will continue through the planning process.

The original PDM grant request was submitted for $2,267,000 of total funding. The funding request includes funds for feasibility studies, environmental studies, engineering and design studies, property acquisitions, and flood control structures including the Shaw Creek relocation or bypass channel, conveyance improvements within Wide Hollow Creek, and bridge design and construction. The funds for the grant will be released by FEMA when all of the environmental surveys have been completed and the Environmental Assessment process has selected a preferred alternative.