Channel Cross Sections of the Nooksack River near North Cedarville, WA, 2017-2021

This data release contains channel cross sections of the Nooksack River near North Cedarville, WA, collected during routine streamgaging and discharge measurement efforts at USGS streamgage 12210700. All cross sections were collected using an acoustic doppler current profiler (ADCP) from the downstream side of the Highway 542 bridge. Raw ADCP measurement data were processed using a combination of WinRiver II and AreaComp2. The mean gage height during the measurement was used to convert ADCP depth measurements into elevations relative to the gage datum. The known offset between local gage datum and the North American Vertical Datum of 1988 (NAVD88) was further used to convert gage datum elevations to absolute elevations referenced to NAVD88.

Cross section stationing is given as distance from the river-right most point of the ADCP transect. Water's edge points, based on noted distances from the edge of the ADCP surveys to the actual edge of water, are included for all cross sections. For ADCP measurements when global nation satellite system (GNSS) position was used, each cross section point was associated with an approximate XY coordinate position, in Washington State Plane North US Survey Feet (NAD83 2011).

These cross sections are not exactly aligned in either the cross-channel or along-channel direction. When GNSS data was collected during the ADCP measurements, the cross sections varied by up to 70 feet downstream of the Highway 542 bridge. Likewise, the 'zero' station simply reflects the river-right edge of the ADCP transect, which will necessarily change as a function of flows and details of vegetation and channel geometry near the bank. These cross sections are then primarily intended to qualitatively illustrate the extent of channel change at this site and are not intended for quantitative analysis of that change.