The Union SWCD intends to provide updated and accurate information about the Buffalo Flats Floodplain project for our conservation partners and the interested public on the several pages of this website. We have attempted to organize this information in a way that makes it easy to find and read. Please reach out to our staff by email, phone, or visits to our office if you have any questions or concerns about this project and information provided. With our small staff and a heavy workload, new information may be available that is not posted yet. The Union SWCD provides monthly updates of design and planning products to the Union City Council and periodically to the Focus Group as the project completes milestones noted in the timeline.

The Buffalo Flats Floodplain Planning project includes both Little Creek and Catherine Creek on property owned by Buffalo Peak Land & Livestock, LLC. Little Creek and Catherine Creek restoration designs are on separate timelines because of differences in their size and scale, physical modifications and infrastructure, and water rights that must be considered. The accuracy and quality of analysis is much higher if the two stream systems are evaluated separately, while still considering the entire project as a combined area. Due to its lesser complexity, Little Creek is furthest along; on-ground project activities in Little Creek are expected to start prior to work on Catherine Creek. 

October 2024

Little Creek: The technical design team has been progressing toward the 80% design stage since February 2023 when the 30% design package was distributed for review. The 30% Design package was reviewed by the landowners and project technical team, local conservation partners, and the BPA Regional Review Team. Comments and input received from these reviews are addressed through edits to the design. During summer and fall of 2023 the design team continued to gather site specific, technical information to better inform the design and meet project goals. An archaeology and cultural resources survey was completed in August and September with a pedestrian survey (surface only) for the north portion of the meadow area around Little Creek. Following the surface survey, several shovel pits (~120) were excavated by hand throughout the meadow to look for subsurface items. Areas around discovered historic and culturally significant items were investigated further to better define area boundaries to avoid disturbance. Field surveys were fully completed by October 2023 and a report was developed and submitted to Oregon State Historic Preservation Office (SHPO) to explain findings and request concurrence of those findings.

In addition, the design team organized and implemented the excavation of approximately 30 soil pits in the meadow around Little Creek to inspect the composition of the soil profile and static water elevation. These pits were inspected and refilled within 48 hours of excavation and provided important information about the subsurface materials and conditions in the Little Creek floodplain. Three permanent groundwater monitoring wells (piezometers) were also installed in the western portion of the meadow to measure the depth to the free water surface throughout the year. A common objective for floodplain restoration projects is to raise the elevation of groundwater in relation to the ground surface and surface stream channels. The three monitoring wells installed adjacent to Little Creek will not be used to pump or remove water but will provide a way to continually measure and observe groundwater elevation, especially in relation to the surface water elevation in Little Creek.

Beginning in the fall of 2023, the hydraulic engineers and modelers are analyzing site conditions and hydraulic modeling results to develop existing and proposed condition scenarios. The hydraulic model results will provide very important information to the engineering team for evaluating flood risk and and potential impacts to surrounding properties from the proposed restoration actions. The 80% level of design was initially expected in early 2024, but as modeling output was assessed and additional review was completed by the technical team, changes to the design created a need for additional work and a delay in producing the 80% design. Part of this additional work included a change in the approach to designing for the floodprone area and elevation of the 100-year recurrence flow. After discussions with Oregon FEMA, there was agreement between FEMA staff and the engineering team to accept the existing condition model as a baseline, rather than the 1978 FEMA Floodplain Map. The proposed condition for the project is now being designed for a zero rise in the 100-year flow elevation, meaning that the project actions will not increase flood water levels above the existing, pre-project condition.

On September 28, 2024, the Draft 80% design package (includes Basis of Design Report, Design Drawings, Hydraulic Report) was delivered to the Union SWCD and technical design team. The 80% package is going through an internal technical review and editing before being released to other interested parties and the public. Once the internal review is complete, the 80% design package will be provided to the local Atlas Implementation Team and the Bonneville Power Administration review team for review. In addition, it will be posted on this website and provided to the Union City Council and Focus Group. The Union SWCD intends to convene the Focus Group for a meeting in the fall of 2024. Regulatory and environmental permits and requirements will be addressed beginning this fall and will include reviews by the City of Union Administrator and Union County Planning Department. Construction is now likely to occur during the summer of 2025 on the Little Creek portion of the Buffalo Flats Floodplain Project.

Catherine Creek: At the request of the Union SWCD and the technical team, the Oregon Department of Transportation (ODOT) is assisting by conducting a feasibility study and cost estimates for alternative alignments of Highway 203 along Catherine Creek on the Buffalo Peak Land & Livestock property. ODOT began this work in summer 2023 with site surveys to develop an elevation layer of the area. Alternatives for a new alignment and location of Highway 203 are being developed with consideration of safety concerns, maintenance, weather impacts, construction feasibility, cost, and environmental impacts. This feasibility study is scheduled to take place through 2024. The Catherine Creek portion of the project and potential changes to the alignment of Highway 203 are only conceptual ideas at this time. No designs have been developed and no action is being taken for actual on-ground construction.

The following timeline diagram illustrates the progress of both the Little Creek and Catherine Creek portions of the project.

Public Outreach: Union SWCD continually updates the project’s online Frequently Asked Questions page and resource sheets. Any significant project updates or additional resources will continue to be posted to this website (www.buffalo-flats.com).  We are also continuing to work directly with the project’s established Focus Group to share information and receive feedback that helps us communicate project actions with the public and understand community concerns. 

The Union SWCD welcomes any questions and inquiries about the project. If you have questions or want to discuss the project, please contact us at 541-963-1313 or email Jim Webster at jwebster@unionswcd.org or Aaron Bliesner at abliesner@unionswcd.org.