Wapato Access Feasibility Study

Transcription

1 Wapato Access Feasibility Study David Gorman, PE Michael Rounds, PE August 5, 2011

2 Lower Columbia River Estuary Partnership (LCREP) Non-profit two state public-private initiative Primary Responsibility: Comprehensive Management Plan for the Lower Columbia River (LCR) Mission: Rehabilitate, Enhance, Protect, Conserve, Create, and Restore Tidal Wetlands and Related Key Habitats In the LCR Project Funding by Bonneville Power Administration (BPA) Page 2

3 Columbia River Basin Basin Map Basin Statistics Basin Area is 258,000 Sq. Miles Drains 7 States and BC 1243 Miles Long Largest River Flowing to Pacific from North America Supports Many Species of Anadramous Fish Page 3

4 Columbia River Average Daily Flow at The Dalles, Oregon Pre-Regulation ( ) Post-Regulation ( ) t The Dalles (cfs) Max 6-Jan 14-Jan 22-Jan 30-Jan 7-Feb 15-Feb 23-Feb 3-Mar 11-Mar 19-Mar 27-Mar 4-Apr 12-Apr 20-Apr 28-Apr 6-May 14-May 22-May 30-May 7-Jun 15-Jun 23-Jun 1-Jul 9-Jul 17-Jul 25-Jul 2-Aug 10-Aug 18-Aug 26-Aug 3-Sep 11-Sep 19-Sep 27-Sep 5-Oct 13-Oct 21-Oct 29-Oct 6-Nov 14-Nov 22-Nov 30-Nov 8-Dec 16-Dec 24-Dec Flow at Date Page 4

5 Cumulative Impacts to Columbia River ESA Listed Anadromous Fish Habitat Harvest Dams Migration Obstacle Upstream Passage Downstream Passage Increased predation Flow Regulation Reduced Peak Flows Increased Low Flows Habitat Loss Diking, Draining, Development Hatcheries Page 5

6 Historic Ecosystem Losses in the Lower Columbia River Estuary Last 150 Years 52,000 acres wetland/marsh habitats 3,800 acres of riparian forest habitat 27,000 acres of forested wetland Wapato Access FS August 5, 2011 Page 6

7 Percentage Change in Columbia River Estuary Habitat Types Habitat Type Change Deep Water -7% Medium Depth Water -25% Shallow Tidal Flats +10% Tidal Marsh -43% Tidal Swamp -77% Page 7

8 FCRPS Biological Opinion Biological Opinion Issued by NOAA Fisheries 2008 Action Agencies Concluded Operation of These Projects Without Further Mitigation, Would Jeopardize 13 Listed Species of Fish Mitigation Measures Include 73 Detailed Reasonable and Prudent Alternatives (RPA) RPA Alternative 37: Identify and Implement Estuary Habitat Restoration Projects That Yield High Survival Benefits Page 8

9 Wapato Access Floodplain Reconnection Feasibility Study Objectives Collect and Analyze Baseline Data Determine Habitat Enhancement Alternatives Develop Planning Level Analysis of Alternatives Develop Conceptual Design of Preferred Alternative Develop Planning Level Cost Estimate Page 9

10 Wapato State Access Area Description Located on Sauvie Island Owned by Oregon State Parks Confluence of Willamette and Columbia 156 Acres with 41 Acres of Wetland Separated from Multnomah Channel by Levees Page 10

11 Aerial of Wapato State Access Page 11

12 Site Vicinity Page 12

13 Study Approach Water Surface Elevation Development Inundation Study Vegetation Survey and Wetland Delineation Review Outmigration Data Page 13

14 Water Surface Elevation Development Used HOBO Data Logger Recorded Data from May to August 2010 Page 14

15 HOBO Data vs. Gage Data ft) Water Surface Elevation (f /6/2010 5/21/2010 6/5/2010 6/20/2010 7/5/2010 7/20/2010 8/4/2010 Date HOBO Data St. Helens Gage Vancouver Gage Page 15

16 Water Surface Elevation Development Developed Long Term Water Level Record St. Helens Gage Adjusted Calibration to Variations in Water Level Differential Long Term Record ( ) Page 16

17 Inundation Mapping Questions How much area is inundated? Where does the water accumulate? Where can potential entrapment take place? Is there potential to flood neighboring properties? Page 17

18 LiDAR Topographic Data LIDAR data with site specific survey used to develop inundation maps Page 18

19 Extent of Inundation and Water Depth Page 19

20 Outmigration Study Chinook January May Coho April - June Steelhead November - May Page 20

21 Monthly Percent of Time Above WSE January February March April May June November December >11.3 feet 42.0% 30.8% 30.8% 36.0% 58.7% 52.9% 14.4% 31.0% >12 feet 32.4% 21.9% 20.3% 24.2% 43.9% 43.1% 8.9% 21.5% >13 feet 22.3% 13.6% 11.4% % 31.9% 4.4% 12.6% >14 feet 13.9% 7.8% 5.1% 6.6% 17.5% 22.4% 2.0% 8.0% >15 feet 8.2% 4.8% 3.5% 3.6% 12.2% 13.0% 0.8% 5.5% >16 feet 5.7% 2.9% 2.1% 2.3% 8.7% 8.8% 0.4% 3.7% >17 feet 3.8% 1.3% 1.2% 2.1% 6.4% 6.2% 0.3% 2.8% >18 feet 3.6% 1.2% 1.1% 2.0% 6.0% 6.1% 0.2% 2.6% >19 feet 1.8% 0.5% 0.1% 1.9% 4.0% 3.5% 0.2% 1.9% >20 feet 1.1% 0.3% 0.0% 1.1% 1.8% 2.7% 0.2% 1.0% Page 21

22 Preferred Alternative Design Page 22

23 Preferred Alternative Restore areas B, C, D, and E Excavate Channel Installation of a Trail Crossing Construct Internal Channel to Prevent Entrapment Raise Levees to Prevent Flooding of Neighboring Properties Restore Wetland Areas with Native Plantings Page 23

24 Next Steps Collect additional data on local hydrology Discuss specific Design and Criteria with Stakeholders Complete 1D and 2D modeling of site and channels Complete Final Design of Channels, Levees, and Planting Plan Complete Construction Cost Estimate Page 24

25 Thank You David Gorman, PE Ecosystem Restoration Engineer AECOM Portland, Oregon Michael Rounds, PE Hydraulic Engineer AECOM Portland, Oregon Wapato Access FS August 5, 2011 Page 25