LUBA Remand: Laurel Ridge Zone Change (Z 15-5) <br />To test the accuracy of the applicant's city limits line, staff took measurements on the original, <br />full-size copy of Sheet ZC-2. As explained below, this was basically a "spot check" of the city <br />limits line. Using an engineer's scale, staff found that the distance between the western property <br />boundary and the far western reach of the city limits line (directly west of the subject property) <br />is approximately 850 feet. A reduced copy of Sheet ZC-2 with staff's notes is included as Figure 1. <br />Staff made a second measurement on the original, full-size copy of the "Hendricks Hill Property <br />Annexation" map (file #A 07-10), which led to annexation approval for the subject property. Not <br />surprisingly, staff measured 850 feet between the western property boundary and the eastern <br />side of the "green finger"' (which also coincides with the city limits boundary). A scanned, <br />reduced version of this map with staff's notes is included as Figure 2, however the original full- <br />size copy of the map is available in the application file for reference and is hereby incorporated <br />into the record. <br />Staff made a third measurement within ArcGIS (Geographic Information System) mapping <br />software, and the same measurement of 850 feet was made with the GIS data available to the <br />Cityz. These data layers (city limits boundary and tax lots) are generally accurate and are used <br />for a wide variety of city mapping projects including legal noticing requirements. Staff has <br />provided a graphical representation of this measurement as Figure 3. <br />As a result of this additional analysis and measurement, staff agrees with LUBA's finding that the <br />city limits line does provide a valuable, additional referent that helps to more accurately locate <br />the plan designation boundary on the subject property consistent with the Metro Plan diagram. <br />Using Multiple Referents <br />Map Use: Reading and Analysis, Sixth Edition is a widely used college textbook for geography and <br />cartography students. The book provides the following definition of "georeferencing" (the <br />technical name for the process of using map referents to align different maps or data layers): <br />"The procedure used to bring data layers into alignment via known ground location control <br />points or, alternatively, the procedure of bringing a map or data layers into alignment with the <br />earth's surface via a common coordinate system." The important part to note is the plural in <br />"control points" - City of Eugene staff with professional GIS experience note that accurately <br />registering a map image (i.e. the Metro Plan diagram) to map data layers can only be <br />accomplished by using multiple map referents (or control points). If only one map referent is <br />used, issues like the "sliding effect" on East 30th Avenue can occur. As explained by LHVC in <br />previous proceedings before the HO and Planning Commission, "sliding" of the referent can occur <br />in the case of East 30th Avenue because it is a linear referent, as opposed to a point (i.e. a street <br />intersection or the corner of two property lines). <br />1 Green Finger: Tax Lot 301 of Assessor's Map 18-03-09-20; owned by City of Eugene and designated POS <br />2 City Limits Data Layer: originates from Lane County of Governments (LCOG); data has "high quality - current and <br />complete" rating, and a "Quality 2 - Maps that meet National Map Accuracy standards. 90% features within 40' at <br />1:24,000" positional accuracy rating. <br />Tax Lot Data Layer: originates from Lane County Dept. of Assessment and Taxation <br />City of Eugene • 99 W. 10th Ave. • Eugene, OR 97401 • 541-682-5481 • 541-682-5572 Fax <br />www.eugene-or. gov/plan n in g <br />