Calapooia River - Albany Assessment and Project Implementation Plan Final Report Site Assessment on the Willamette River. Submitted To: Ms. Tara Davis, Executive Director Calapooia Watershed Council PO Box 844 Brownsville, Oregon 97327 Submitted By: River Design Group, Inc. 311 SW Jefferson Avenue Corvallis, Oregon 97333 April 29, 2011 Calapooia - Albany Assessment and Project Implementation Plan EXECUTIVE SUMMARY The Calapooia Watershed Council and the City of Albany retained River Design Group, Inc. to complete an existing conditions assessment and restoration opportunities prioritization plan for several waterbodies in the vicinity of Albany, Oregon. The assessment reaches include the lower 3 miles of the Calapooia River, the Willamette River and adjacent agricultural areas from RM 114 to RM 122, lower Periwinkle Creek, Thornton Lake, and the Albany oxbow lakes adjacent to the Willamette River. This effort follows the Calapooia River Watershed Assessment (CWC 2004) which provided an evaluation of the drainage at the watershed scale, and the Middle Calapooia Assessment (RDG 2007). This document serves two purposes; one, as an assessment, it presents information on historical and existing conditions based on field data collection, remote sensing, and existing data review. Secondly, the document serves as a river corridor restoration project prioritization plan that highlights restoration actions to address limiting factors and achieve restoration goals. Individual opportunities are identified for each of the target waterbodies. -i- April 2011 Calapooia - Albany Assessment and Project Implementation Plan TABLE OF CONTENTS EXECUTIVE SUMMARY .......................................................................................................................... I GLOSSARY ............................................................................................................................................... XI 1 INTRODUCTION ............................................................................................................................. 1 1.1 Purpose of Effort .......................................................................................................................................... 1 1.2 Report Structure........................................................................................................................................... 3 2 METHODS ........................................................................................................................................ 3 2.1 Site Reconnaissance and Field Data Collection ................................................................................. 4 2.1.1 Bank Stabilization Structures and Floodplain Levee Mapping .................................................... 4 2.1.2 Bank Erosion Site Mapping .......................................................................................................... 4 2.1.3 Infrastructure Location Mapping................................................................................................. 5 2.1.4 Habitat Conditions ....................................................................................................................... 5 2.2 Remote Sensing............................................................................................................................................. 5 2.3 Inundation Mapping.................................................................................................................................... 5 3 PROJECT AREA OVERVIEW ........................................................................................................ 6 3.1 Introduction ................................................................................................................................................... 7 3.2 Historical River Corridor and Founding of Albany .......................................................................... 7 3.3 Contemporary Land Uses .......................................................................................................................... 9 3.4 Fisheries ....................................................................................................................................................... 10 3.5 Project Area Hydrology........................................................................................................................... 14 3.5.1 Willamette River Hydrology ...................................................................................................... 15 3.5.2 Calapooia River Hydrology ........................................................................................................ 19 3.5.3 Thornton Lake Hydrology .......................................................................................................... 22 3.5.4 Periwinkle Creek Hydrology ...................................................................................................... 23 3.5.5 Albany Oxbow Lakes Hydrology ................................................................................................ 24 3.6 Riparian Corridor ..................................................................................................................................... 25 3.7 Summary ...................................................................................................................................................... 25 4 WATERBODY DESCRIPTIONS ................................................................................................. 25 -ii- April 2011 Calapooia - Albany Assessment and Project Implementation Plan 4.1 Calapooia River .......................................................................................................................................... 26 4.1.1 Historical River Corridor Analysis .............................................................................................. 26 4.1.2 Inundation Mapping .................................................................................................................. 28 4.1.3 River Corridor Observations ...................................................................................................... 29 4.1.4 Ecological Considerations .......................................................................................................... 37 4.1.5 Summary .................................................................................................................................... 38 4.2 Willamette River ....................................................................................................................................... 38 4.2.1 Historical River Corridor Analysis .............................................................................................. 38 4.2.2 Inundation Mapping .................................................................................................................. 41 4.2.3 River Corridor Observations ...................................................................................................... 42 4.2.4 Ecological Considerations .......................................................................................................... 50 4.2.5 Summary .................................................................................................................................... 51 4.3 Periwinkle Creek ....................................................................................................................................... 51 4.3.1 Historical Stream Corridor Analysis ........................................................................................... 51 4.3.2 Inundation Mapping .................................................................................................................. 53 4.3.3 River Corridor Observations ...................................................................................................... 54 4.3.4 Ecological Considerations .......................................................................................................... 58 4.3.5 Summary .................................................................................................................................... 59 4.4 Thornton Lake ............................................................................................................................................ 59 4.4.1 Historical Oxbow Lake Analysis ................................................................................................. 59 4.4.2 Inundation Mapping .................................................................................................................. 61 4.4.3 River Corridor Observations ...................................................................................................... 63 4.4.4 Ecological Considerations .......................................................................................................... 66 4.4.5 Summary .................................................................................................................................... 67 4.5 Albany Oxbow Lakes ................................................................................................................................ 67 4.5.1 Historical Oxbow Lake Analysis ................................................................................................. 67 4.5.2 Inundation Mapping .................................................................................................................