Biodiversity Guide - The Intertwine

egional conservation strategybiodiversity guideappendix a Land Cover Mappingfigure A-2Watershedsfigure A-3TopographyKSt. HelensHRidgefieldLaCenterFSt. HelensRidgefieldLaCenterScappooseBattleGroundScappooseBattleGroundJBanksLForestGroveCorneliusHillsboroPortlandMVancouverDCamasWashougalTroutdaleGreshamGBanksForestGroveCorneliusHillsboroPortlandVancouverCamasWashougalTroutdaleGreshamThe extent ofthe Intertwineregion was definedto encompass thePortland-Vancouvermetropolitan area and itssurrounding landscapesand watersheds. It connectswith, but largely excludes,the main Cascade and CoastalRanges and the heart of theWillamette Valley; these areas arewell represented by previousprioritization efforts. This mapdepicts the watersheds reported on inthe RCS report, which include HUCsub-basins, partial sub-basins, andNewbergBWoodburnBeavertonTigardTualatinSherwoodWilsonvillewatersheds. The region includes eight HUC-4 sub-basins; in thecase of two—the Lower Willamette and the Middle Willamette—wechose to report on the watershed (HUC-5) level.LakeOswegoAMilwaukieCanbyIEOregonCityMolallaHappyValleyDamascusCEstacadaSandyNewbergBeavertonTigardTualatinSherwoodWilsonvilleAlthough land use in theIntertwine region is diverse, it islargely consistent with elevationzones. This hypsometric map colorsthe region in five elevation classes.WoodburnLarge patches of forest are generallyconstrained to the highest elevationzones. Agriculture and (sub)urbandevelopment dominate the 50-200’ and 200-600’ zones, withagriculture extending above 600’ mostly in the eastern portion ofthe region, where it often intergrades with forest.LakeOswegoMilwaukieCanbyOregonCityMolallaHappyValleyDamascusSandyEstacadaRCS Defined WatershedsHUC 5 watersheds are lightly outlined * Represents a partial sub basinA - Abern ethy C reek-Willamette River Watershed (87,000 ac)B - Ch ehalem Creek-Willamette River Watershed (78,000 ac)C- Clackamas Su b Basin * (158,500 ac)D - Hayden Island-Co lu mbia River Watershed (18,500 ac)E - John so n Creek Watershed (60,000 ac)F - Lewis Su b Basin* (221,000ac)G - Low er Colum bia-Sand y Sub Basin* (217,500ac)H - L ower Columbia-Slatskan ie Sub Basin* (22,000ac)I - Molalla-Pu dding Sub Basin* (181.000ac)J - Salmon Creek-Fro ntal Columbia River Watershed (131,500ac)K - Scappoo se Creek-Fro ntal Columbia River Watershed (181,000ac)L - Tualatin Sub Basin (453,500ac)M - Willamette River-Fro ntal Columbia River Watershed (78,000ac)Elevation range 0 - 50 feet8.2% of the Region (150.000 acres)ColumbiaRiver and lower portions of the Willamette RiverElevation range 50 - 200 feet19.3% of the Region (354.000 acres)Mostly Floodplain, Urban and Agriculture areasElevation range 200 - 600 feet34.2% of the Region (627.000 acres)Mostly Agricultue and Urban areasElevation range 600 - 1,000 feet16.4% of the Region (301.000 acres)Transition lands; mix of agriculture and forestElevation range 1,000 - 4,380 feet21.6% of the Region (396.000 acres)Natural and industrial forest lands166 167