| Client: | Umatilla Basin Watershed Council |
| Partners: | Confederated Tribes of the Umatilla Indian Reservation |
| Location: | Echo, Oregon |
| Date: | On-going |
A levee on the Umatilla River disconnects the adjacent floodplain from the river.
|  | UBWC retained RDG to complete a site survey and assessment on a 2,300 ft reach of the Umatilla River. The reach spanned two properties. A floodplain levee was the primary feature in the reach affecting river hydraulics and habitat. RDG was tasked with developing and evaluating three alternatives for addressing the levee. RDG used RTK GPS to characterize the river bathymetry and integrated the field data into a LiDAR data set. HEC-RAS was used to model the existing condition and two levee modification alternatives including levee breach and full levee removal. ArcGIS and GeoRAS were used to produce visualization figures of the hydraulic output. The channel and floodplain hydraulics were also compared to preferred habitat criteria for juvenile Chinook and steelhead. A draft report and plan set have been submitted to the UBWC’s technical team for review.
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