Bank Stabilization vs. Streambank Restoration in Design Practices

1. Bank Stabilization

2. Bank Stabilization Vs. Streambank Restoration • Bank Stabilization is associated with protecting highway structures • Bridges, culverts, roads • see pgs 26-27 • Includes streambed scour repair • Main difference, unvegetated riprap allowed to protect structures • ODOT Hydraulics Manual if protecting highway structures or “Design Deviation” Page # references are for May 2013 User’s Guide

3. Bank Stabilization (cont.) • Unvegetated riprap where necessary: • Fill a local scour threatening a structure • Stabilize a footing, facing, head wall, or other structure necessary to prevent scouring, downcutting, fill slope erosion, or other failure at an existing culvert or bridge.

5. Bank Stabilization (cont.) • Limit amount of rock to minimum necessary to protect integrity of structure • Whenever feasible, include soil and veg. • Offsetting only required if net increase above OHW or not associated with protecting structures

6. Bank Stabilization (cont.) • Biotechnical streambank stabilization, engineered log jam, avulsion prevention • Offsetting not required

7. Bank Stabilization (cont.) • Vegetated riprap with large wood near highway structures requires engineer approval Older Design

8. Later Design

9. Latest Design

10. Bank Stabilization (cont.) • Stream barbs, non-porous partially spanning weirs, full-spanning weirs, other in-stream flow control structures • Requires Offsetting & Services Approval

11. Streambank Restoration • Emphasis on restoring ecological function of eroded/damaged streambanks • Design standards apply to enhancements and site restoration • Bank shaping, erosion controls, soil reinforcements, plantings • Reshape streambank to natural topography • Don’t change location of streambank toe • LWM when appropriate to system • Rock only allowed as ballast for LWM • See pgs 30-31 for more information

13. Emergencies & Major Hazards • Not typically funded by FHWA • When state/locally funded, use SLOPES IV when Corps permit • If no Corps permit, follow Bluebook • FAHP may be used for follow-up repairs if Federal-Aid Highway or other FHWA funding • Minimization measures, design standards as per related FAHP activities, particularly IWW • Regardless of ESA permit, similar Design Standards

14. Pile Driving/Pile Removal

15. Pile Driving near Steller Sea Lions Columbia River (up to Bonneville Dam) or within 10 mi. of known haul-out Known Haul-out Locations See Appendix 8 Biological Monitoring Qualifications Stop work if present within 1,200 feet More Information About Specs Later Otherwise Observed During In-Water Work? Page/Append. references are for May 2013 User’s Guide

16. Haul out locations: • Three Arches Rock & Sea Lion Caves • Cape Arago State Park • Orford Reef & Rogue Reef • Oregon Islands National Wildlife Refuge • South Jetty Columbia River

17. (Appendix 8)

18. (Appendix 8)

19. Pile Installation Standards relevant when ESA-fish may be present (pg 36) Concrete, Steel Round < 24” diameter, Steel H-Pile < HP24, or untreated wood pile Minimize impact hammer Specify vibratory whenever possible “Proofing” No impact hammer when ESA fish <2 gm present Sound attenuation for impact/steel piles See Appendix 7 More Information About Specs Later

20. Acoustic Isolation • Use tide cycles • Dewater area • Seasonal Timing

21. If water velocity is 1.6 fps or less, surround the pile being driven with a bubble curtain (per Appendix 7), that must distribute small air bubbles around 100% of the pile perimeter for the full depth of the water column.

22. If water velocity is greater than 1.6 fps, surround the pile being driven by a confined bubble curtain that must distribute air bubbles around 100% of the pile perimeter for the full depth of the water column.

23. Bubble Curtain Requirements (Appendix 7) Due to water depth there may be a need for multiple bubble rings Rings should be no more than 20 in from the outside surface of the pile The ring should be flush with the bottom substrate and attached to a frame In a confined bubble curtain, spacers or pile guides should be included to keep the walls of the system from touching the pile being driven Pile Driving Sound Attenuation

24. Pile Driving Sound Attenuation (cont.) • Confined bubble curtain: • Sufficient room at top, above the maximum water level expected • So when the air delivery system is adjusted properly, curtain does not act as a water pump • Install pressure meters • At all inlets of aeration pipelines and at points of lowest pressure in each branch of the aeration pipeline • Install main line flow meters • at each compressor and at each branch of the aeration pipelines at each inlet • See Appendix 7 more more details

25. Performance: Unconfined bubble curtains In Washington, effective up to 17 dB attenuation (9 to 12 dB more typical) Confined bubble curtains In Washington, lack of data Other locations, effective 9 dB to 30 dB Expectations for FAHP Env. Inspections Monitoring Pile Driving Sound Attenuation (cont.)

26. Pile Removal Requirements: (pgs 37-38) Use vibratory hammer when possible If using crane, “wake up” (vibrate/wiggle) Non-creosote pile Try to remove all in work zone See pg 37 for more details If breaks during removal & in a shipping/dredging channel, mark locations of broken piles with GPS Data in Project Completion Report Page # references are for May 2013 User’s Guide

27. Removing creosote piles: Minimize sediment disturbance & turbidity Floating boom, equipment out of water, etc. (see pg 37-38) Dispose as Hazardous Waste Pile Removal (cont.)