Selection of Aquatic Organism Passage Design Methodology Based on Geomorphic Setting, Site Conditions, and Engineering Constraints

Transcription

1 Selection of Aquatic Organism Passage Design Methodology Based on Geomorphic Setting, Site Conditions, and Engineering Constraints Robert Gubernick R.G. USDA Forest Service Region 9 Eastern Region

2 Acknowledgements for Content, Images, and Slides Kozmo Bates Consulting Fish Passage Engineer Marcin Whitman California Dept. of Fish and Wildlife Dan Cenderelli USFS Stream System Technology Center Mark Weinhold USFS White River National Forest Traci Sylte USFS Lolo National Forest Kim Johansen USFS Siuslaw National Forest (retired) Scott Jackson Univ. of Massachusetts Dan McKinley USFS Green Mountain National Forest Jeremy Krohn USFS Green Mountain National Forest Tomas Dunklin Dunklin Photography Brett Roper USFS Forest Science Laboratory

3 Discussion Topics Aquatic Organism Passage (AOP) Regulations USDA Forest Service AOP and Design Priority Policy AOP Project Objectives Site and Geomorphic Constraints Engineering Constraints Stream Simulation Design Limitations Site Limitations Benefits Geomorphic Design Design Limitations Site Limitations Benefits Hydraulic Design Design Limitations Site Limitations Benefits Chequamegon N.F.

4 Laws Pertaining to USDA USFS NFMA Implementing Regulations (36 CFR ) Fish and wildlife habitat shall be managed to maintain viable populations of existing native and desired nonnative vertebrate species in the planning area. No management practices causing blockages of water courses, or deposits of sediment shall be permitted preserve and enhance the diversity of plant and animal communities so that it is at least as great as that which would be expected in a natural forest. CWA Silviculture road exemption (40 CFR 232.3) The design, construction and maintenance of the road crossing shall not disrupt the migration or other movement of those species of aquatic life inhabiting the water body.

5 National USFS AOP Policy USDA Forest Service Interim Directive for Designing Road-Stream Crossings Aquatic for Organism Passage Design (2008) Primary Design Priority: Aquatic organism passage and ecological connectivity is the goal and the first design priority for crossing streams that provide habitat for aquatic life. Other Design Considerations: Minimizing the consequences of plugging and overtopping, including the ability to prevent stream diversion. Sufficient hydraulic capacity, including the requirement that headwater depth does not cause pressurized flow at the maximum flood. Maximize benefits while minimizing life cycle cost.

6 Peak Spawning Time D I S C H A R G E Migration Timing For Several Fish Species There is almost no time when some life stage of some aquatic species is not moving in a stream Jan Mar May July Sept Nov Graphic: Brett Roper

7 Road-Stream Crossing Design Methods: National USFS AOP Policy 2008 Stream Simulation Design: Bridge, arch, or embedded culvert designs providing stream simulation. The USDA Forest Service (2008) stream simulation design guidelines should be used when possible. Geomorphic-based Channel Design: Reconnects the upstream and downstream channel while meeting most fish and other aquatic organism movement and habitat needs. Hydraulic Design: Designs based primarily on hydraulic capacity should be limited to low stream gradients, where the structure is constantly partially submerged. Baffled culverts or structures designed with a fishway are discouraged and should be used as a last resort, especially if they also hinder terrestrial organism passage.

8 Project Objectives What is Success? Passage for target species Ecological connectivity Minimize delay of target species Passage for all aquatic organisms Low cost Block introduced species Public safety Habitat restoration Durability Public education Wildlife passage Protected from floods, debris, sediment

9 What are the Passage Objectives & Constraints Relative to Design Method Does Not Maintain all geomorphic processes and does not pass all Biota Fishway Baffles Weirs - Ecological solutions at Road Crossings + Roughened Channel with Roughened Constructed Channel Bedforms Maintains all geomorphic processes and pass all Biota Simulated Natural Bed with Bedforms Hydraulic Design Geomorphic Design Stream Simulation Design

10 Hydraulic Design Weir / Baffles Stream Simulation M.Whitman K.Bates Pass target species for a life stage Hydraulic Design Fishway - Ecological solutions at Road Crossings + M.Whitman K.Bates Geomorphic Design Pass all species

11 What are the Site & Geomorphic Conditions Relevant to Choosing the Design Method Is the channel stable or incising? How much will it change over time How much Elevation differential exists (Inlet to Outlet)? Are there road impounded wetlands upstream or other features that must be maintained? Are you on an alluvial fan or is the area prone to debris flows? Is woody debris a problem? Is there high bed load transport? K.Bates

12 relative elevation (m) ptc-h ptc-h { ptc-m ptc-h ptc-m ptc-h lw-l st-h ptc-h lw-m lw-m lw-m ptc-m lw-l ptc-m lw-l Channel Segments STREAMS bedrock channel CHANGE OVER TIME. A vertical exaggeration = 10 log weir, low stability slope segments (A,B,C,D,E,F,G,H) upper vertical adjustment potential line lower vertical adjustment potential line 2 B tributary C 3 bedrock 4 D bedrock along right bank F , 27.0 G F,G a , 27.0, 20.2 H b,c , 18.0 a. Percent gradient difference when compared to slope segment F. b. Percent gradient difference when compared to slope segment G. c. When compared to combined slope segments of F and G, the percent gradient difference is 33.3% distance downstream (m) E sediment wedge Existing culvert diameter 3.1 m length 22 m culvert plunge pool 7 rock weir F 8 bedrock, left bank of plunge pool 9 G Range of Vertical Adjustment 10 H 1979 T.Sylte 1998 T.Sylte

13 TYPICAL LOW GRADIENT CHANNEL How do the Different Design Methods Fit the Channel Flood swale Flood prone area Floodplain Bankfull channel Natural channel with Bankfull channel Flood plain Ecological processes

14 Bankfull channel width Hydraulic Design Method Perspective View on a Road Crossing Site Typically constrict the natural channel Rigid structure in dynamic environment

15 Bankfull channel width Geomorphic Design Method Perspective View on a Road Crossing Site Vary in the degree of constriction the natural channel. Range from 50% to zero constriction when compared to the Bankfull width Bed designed for permanence up to Design Q essentially rigid

16 Bankfull channel width Stream Simulation Design Method Perspective View on a Road Crossing Site No constriction the natural channel bankfull width Accounts for floodplain conveyance, most geomorphic processes, and all aquatic passage needs Flexible design to account for long term changes in bed elevations Stream Simulation Objectives Passage of all aquatic organisms Maintain most ecological processes

17 Stream Simulation Design Method Perspective View on a Road Crossing Site No constriction the natural channel & floodplain width Accounts Full spanning for floodplain bridge - conveyance, Objectives all geomorphic processes, Pass and flood terrestrial flows and & debris aquatic passage needs Flexible Passage design of to account all aquatic for organisms long term changes in bed elevations Maintain all stream and floodplain processes

18 What Are The Engineering Constraints Relevant To Choosing The Design Method Alignment (Vert. & Horiz.) Can they be changed? Can the road be relocated? Are there Right of Way constraints? Are utilities present? Can they be relocated? Tongass NF Hightstown, NJ

19 Stream Simulation Design: A channel that simulates characteristics of the adjacent natural channel (reference reach), will present no more of a challenge to movement of organisms than the natural channel. Simulated high gradient channel Mitkof Island, AK.Tongass NF Reference reach Mitkof Island, AK.Tongass NF

20 Stream Simulation Design Limitations Require reference reach within 25% of proposed design grade Constructed Step - Pools Step pools T.Dunklin Tight ROW and large elevation differentials may limit applicability Good experience / results under 8%. >8 % OK for bottomless, questionable for enclosed structures. Proper construction greatest factor. Not intended for cohesive (clay) channels. FDR Mitkof Isl. Tongass NF Structure FDR Gradient Mitkof 7.8% - Isl. Looking Tongass upstream NF 2008 Structure Gradient - 7.8% installed July 2002

21 Stream Simulation Design Site Limitations Not suitable for stream simulation (or any culvert?) Unstable channels aggrading, active alluvial fans, incising / degrading Prone to debris flows CULVERT Rapidly incising channel Debris flow prone Active alluvial fan K.Bates

22 Stream Simulation Design Site Limitations Road Impounded Wetlands Reference reach Stream simulation not achievable. No sediment transport continuity due to wetland acting as a sediment sink, and reference reach at the grade does not exist. Geomorphic or hydraulic design would be required. Old oxbow on terrace cutoff by railroad grade Yakima River K.Bates K.Bates

23 Stream Simulation Benefits Excellent Flood Response Green Mountain National Forest - FR17A - Bottomless Arch Outlet Competed Construction 2010 Post TS Irene Sept D. McKinley J.Krohn Lost largest boulders near outlet and some roughness along stem walls. Structure and road undamaged and structure passes all aquatic organisms

24 Stream Simulation Benefits Excellent Flood Response Green Mountain National Forest - FR17A - Bottomless Arch Inlet Completed Construction 2010 Post TS Irene September 2011 Storm Peak Flow D. McKinley D. McKinley Storm flows did not top over the road. Minimal scour on left side of arch

25 Sustainability and flexibility over time. 100% passage for all A.O. s T.Dunklin Mitkof Isl. Tongass NF 4% stream gradient

26 Geomorphic Design: design that create a nonadjustable streambed inside of a culvert to pass at least some aquatic species. The channel usually resembles the general shape of a natural channel (form based on design gradient) although it may be quite different from the channel in which it is constructed. Coal Creek, Wa. K.Bates 1-Mile Creek, Wa. K.Bates

27 Geomorphic Design Limitations Roughened Channels Highest recommended working gradient is ~ 6.5% for sequence and pool Table XII-1. Recommended range of overall design slopes and maximum elevation drops for various roughened channel bedforms. 1 Larger drops across the roughened channel require breaking up the reach with large pools. 2 A step-pool sequence may include multiple steps; four or five steps per sequence are common. Ca. Salmonid Stream Habitat Restoration Manual July 2009

28 Geomorphic Design Site Limitations Roughened Channels Pigeon River Dam Bypass - Chippewa NF Roughened Channel No real site constraints since the channel bed and banks are designed for permanence Potential issues with vertical changes of the natural channel bed. May cause entrance barriers. Passage limited depends on swimming capability of species and age class What happens when Design Q is exceeded???

29 Geomorphic Design Site Benefits More diversity of species and age classes of aquatic organisms passed than with hydraulic design method Can achieve some passage at some sites with tight ROW

30 Hydraulic Design: A structure with appropriate hydraulic conditions will allow target specie(s) to swim through it. Specie(s) usually set for a specific Life Stage M.Whitman

31 Common Baffle / Weir styles L L Z 0 D Z 2 Z 1 Z Corner Notch Angled K.Bates

32 HYDRAULIC DESIGN LIMITATIONS - BAFFLES Baffles are generally not recommended for culvert slopes greater than 3%percent. Turbulence issues limit the range of passable flows Wood blocks passage K.Bates Bedload accumulation reduces pool depth Low Flow Conditions K.Bates Moderate Flow Conditions Note the turbulence in the Pipe

33 HYDRAULIC SITE LIMITATIONS BAFFLES / WEIRS In streams with wood and high bedload transport, constant maintenance is required to maintain functionality Wood blocks passage M.Whitman M.Whitman Bedload accumulation reduces pool depth Branscomb drainage #15, Mendocino Ca. Branscomb drainage #19, Mendocino Ca.

34 Hydraulic Design and Site Limitations - Fishways Maximum recommended fishway slope is 10% Larger facilities require larger ROW Costs are larger for implementation and long term maintenance Baker Resevior, Wa. Portage Creek S.E. AK. Tongass N.F.. K.Bates

35 Hydraulic Design Benefit Design Lends itself to Retrofitting Structures K.Bates Expansion Ring Baffle

36 Hydraulic Design Benefit Pipes can be jacked under busy highways that can t be shut down or are cost prohibitive for crossing not previously considered for passage. K.Bates K.Bates Dickerson Creek, Washington Jacked pipe with baffles as weirs at low and moderate flows Note: stream simulation can be constructed in jacked culvets 36

37 Art By Tomas Dunklin