DRAFT WILLAMETTE RIVER GREENWAY DESIGN PLAN <br />Following acquisition of the 2009 LiDAR data from DOGAMI, LCOG performed general processing of the <br />data including: <br />• joining junction City, Coburg, Eugene East and Eugene West bare-earth quads into one mosaic, <br />• Smoothing the mosaic with a focal mean (3 x 3 rectangle), <br />• Contouring the smoothed bare-earth mosaic, and <br />• Quality-checking along the edges of the quads to insure matching contours. <br />City staff estimated the Willamette River TOB in GIS using 2-foot contours, slope, and hillshade layer <br />sets derived from the 2009 LiDAR data. The City provided the GIS dataset to Cameron McCarthy for use <br />on the project and consultants conducted a field investigation on October 12, 2021, to test the accuracy <br />of the mapped Willamette River TOB line. City and consultants agreed upon six test sites for the field <br />investigation. The test sites were selected using the following criteria: <br />• Relatively level topography adjacent to the river channel. <br />• Visible changes in the mapped Willamette Giver TOB line from parallel, generally following the river <br />channel, to a varied or horizontal path. <br />• Representative zoning and use (public land, commercial land, and residential land). <br />• Distribution (similar distance between sites; equal number of sites on both sides of the river). <br />Test sites were labeled with a directional identifier (W, E) based which side of the river the site was located, <br />and nearest street name or geographical feature: <br />• W1 Hatten <br />• W2 Briarcliff <br />• W3 Millrace <br />• E1 Riverplace <br />• E2 Valley River Center (VRC) <br />• E3 Frohnmeyer <br />Oregon Department of Geology and Mineral Industries (DOGAMI) contracted with Watershed Sciences <br />to collect the data, produce the Jas and bare earth and highest hit grid files. The point density of the Jas <br />files is 8.14 points/sq meter. The relative accuracy is .163 feet and the absolute accuracy has a RMSE of <br />.13 feet. The LiDAR data was delivered in 2009 in Oregon Statewide Lambert Conformal Conic, NAD83 <br />(HARN) horizontal datum, NAVD88 (Geoid03) vertical datum in international feet. The 2-foot contours were <br />generated from the bareearth grid by LCOG under the direction of Eugene PWE. <br />Map 3.1 Overall WGS Map illustrates the full extent of the Greenway Boundary within Eugene's UGB and the <br />location six test sites, as well as field map enlargements of each test site. Discussion of the methodology <br />used to conduct the field investigation and the findings from that are included in Appendix A: Field <br />Investigation. <br /> - Page 60 of 91 <br />WILLAMETTE RIVER GREENWAY CODE AMENDMENTS 25 <br />