Bathymetric Data Collection Approx. One Year after Levee Work Completion in the Green River near Tukwila, Washington on 20160927

Field Data The fourth ADCP data collection effort for this project was done on September 27th, 2016 represented by these bathymetric point locations on the Green River near Tukwila, WA. Stream surface conditions in the vicinity of the project area were relatively flat and water clarity was good. The upstream and downstream extent of the fishing site was identified by the Muckleshoot’s fisheries biologist Martin Fox to correspond with a traditional fishing location. The upstream extent of the surveyed stream reach was defined by a slight riprap bank geometry change causing a seam in the stream flow. The seam is an observable line on the water surface separating two different flow regimes. Looking downstream and to the right of this seam, a zone of reverse flow was observed off the right bank of the fishing site. At this flow both submerged and unsubmerged woody debris had accumulated along the right bank in the upper extent of the fishing site. The lower extent of the surveyed stream reach was defined where uniform stream flow again occurred across the channel width. Processed Data USGS provided the mean surface water elevation (or mean stage) collected at real-time streamgaging station No. 12113344 approximately 11 river miles upstream of the project surveyed site. The mean stage was estimated over the time period of ADCP data collection for this dataset and was used as the reference elevation for calculating the bed-elevation point data. Latitude, longitude and water depth were exported from the ADCP instrument using VMT (The Velocity Mapping Toolbox), a processing and visualization suite for moving-vessel ADCP measurements (Parsons, D.R., et al., 2013). These data are presented in the accompanying spreadsheet (GreenRiverBathymetry_20160927.csv) where the bed-elevation of the river bottom was calculated by subtracting the measured depth from the mean stage.

[
  "010:12"
]

[
  "geospatial"
]