Benton County Riparian and Wetlands Project with support from the IInnvveennttoorryy RReeppoorrtt Benton County Riparian Update Completed 5/8/2011 and Wetlands Advisory Group Alsea River Falls William L. Finley Wildlife Refuge Jackson Frazier Wetland Inventory Report, Updates and other Project Materials Available on the Project Website at: www.co.benton.or.us/cd/riparian TABLE OF CONTENTS Background ............................................................................................................................................................. 6 Overview of Current Stream/Riparian and Wetland Resource Issues .................................................................. 7 Developing Distinct Alsea Basin and Willamette Basin Riparian and Wetland Inventory .............................10 Purpose and Overview of Inventory: ...................................................................................................................13 Goal, Objectives, and Guiding Principles ..........................................................................................................13 Goal ................................................................................................................................................................13 Objectives: .....................................................................................................................................................13 Guiding Principles..................................................................................................................................................14 Benton County Comprehensive Plan (updated 2007) .........................................................................................14 Benton County Stormwater Management Program for the Corvallis Urbanized Area (2007) ........................14 Benton County Total Maximum Daily Load Implementation Plan (2008) ......................................................15 Inventory Overview ...............................................................................................................................................15 Figure 4 .....................................................................................................................................................16 Inventory Method Selected for Benton County ...................................................................................................17 Adopted Inventory and Protection Method .........................................................................................................17 Inventory Area .......................................................................................................................................................19 Goal 5: Riparian Safe Harbor Inventory .............................................................................................................19 Safe Harbor Inventory Methods ........................................................................................................................21 Mapping Data .....................................................................................................................................................21 Light Detection and Ranging Data (LiDAR) Map Data ...................................................................................21 Review of Existing Goal 5 Riparian Inventory Information .............................................................................24 United States Geological Survey ....................................................................................................................24 Oregon Department of Forestry ......................................................................................................................24 Oregon Department of Fish and Wildlife .......................................................................................................26 Watershed Councils ........................................................................................................................................27 Oregon Department of Agriculture (ODA) and Benton Soil and Water Conservation District .....................27 Wetlands Inventory.............................................................................................................................................27 Local Wetland Inventories (cities) ..................................................................................................................29 Wetland Information compiled from Oregon Wetland Explorer (Oregon State) ...........................................29 Field Verification ...............................................................................................................................................29 Riparian Mapping Accuracy Field Assessment .................................................................................................30 Goal 5: Riparian Areas, Streams, and Wetland Findings .................................................................................32 Goal 6: Water Quality Inventory ..........................................................................................................................32 Overview of Current Water Quality Issues..........................................................................................................32 Willamette Basin Water Quality ........................................................................................................................33 Water Quality Inventory .....................................................................................................................................35 Alsea Basin Water Quality .................................................................................................................................36 Water Quality Mapping Data .............................................................................................................................36 Review of Existing Goal 6 Water Quality Inventory Information ....................................................................36 Oregon Department of Environmental Quality ..............................................................................................37 Willamette Basin.................................................................................................................................................40 Alsea Basin .........................................................................................................................................................40 Priority Inventory Data for Developing Benton County Riparian Protection Policy within the Alsea Basin and Willamette Basin .........................................................................................................................................40 Existing Riparian and Wetland Rules and Regulations .....................................................................................41 Community Meetings .............................................................................................................................................42 Listening Sessions with Landowners Summary ..................................................................................................43 Conclusions .............................................................................................................................................................50 Goal 5: Riparian (Safe Harbor) Resources Conclusions ..................................................................................50 Goal 6: Water Quality Conclusions ...................................................................................................................51 Recommendations, Next Steps ..............................................................................................................................52 Drafting Policy Options ......................................................................................................................................52 Local City Coordination .....................................................................................................................................54 Outreach, Incentives, and Partnerships ............................................................................................................54 Agency to Agency Communication .............................................................................................................55 Voluntary Incentives Scenarios for Landowners with Riparian and Wetland Resources ..............................55 Draft Code--Benton County Stream and Riparian Corridor Protection (SRP) ...............................................65 List of Figures Figure 1 Example Riparian Area Functions and Values ............................................................. 8 Figure 2 Example Wetland Area Functions and Values ............................................................. 8 Figure 3 Alsea Basin and Willamette Basin within Benton County, Oregon ........................... 10 Figure 5 Approved Riparian/Wetlands Inventory Process ....................................................... 18 Figure 6 Benton County General Zoning and Stream Length .................................................. 20 Figure 7 Current LiDAR Mapping Coverage Area .................................................................. 22 Figure 8 LIDAR Based Stream Delineation Locations ...........................................................