Aquatic Organism Passage at Road-Stream Crossings CHUCK KEEPORTS FOREST HYDROLOGIST ALLEGHENY NATIONAL FOREST WARREN, PENNSYLVANIA
TOPICS COVERED Aquatic Organism Passage (AOP) Benefits of AOP Crossings Identifying Passage Barriers Site Assessment Types of AOP Culverts Bottomless Arch Culvert on Bobb s Fork 2
AQUATIC ORGANISM PASSAGE = STREAM SIMULATION Build the stream channel inside the road-stream crossing A channel that will present no more of a challenge to organisms than the natural channel Stream Simulation Structures: Bridge, arch, or embedded culvert designs Shingle Mill Run Proposed placement of structure 3
Shingle Mill Run Bottomless Culvert 1 year after construction was complete 4
OTHER CONSIDERATIONS Designing for stream simulation increases the life of culverts: Decreased failures from flooding and debris plugging Reduced abrasion of from transport of bed load in streams 5
Aquatic Organism Passage- It is NOT just for Salmon Greg A. Syverson 6
Radu Guiasu Scott Jackson 1999 Joyce Gross Joe Bartronis PA Fish and Bpat Robert Jenkins & Noel Burkhead Barry Wicklow 7
FRAGMENTATION OF RIVER, STREAM AND LAKE/RESERVOIR ECOSYSTEMS Ties directly to: Dams Poorly designed roads and trails Direct implications for: Population structure and persistence Ecosystem function Fragmentation, Genetics, and Population Viability 8
Reduced Access to Vital Habitats Spawning habitat Nursery habitat Foraging areas Deep water refuges Seasonal habitats Impacts Genetic diversity 9
EXAMPLE OF AQUATIC HABITAT FRAGMENTATION FROM CULVERTS Culvert replacement restored access to 8 miles of headwater stream habitat. Project cost= $200,000 Cost per mile= $25,000 10
11
Three Different Hydrologic Conditions Fish Negotiate in Culverts 2. Prolonged Swimming Speed Through the Pipe Flow Direction 1. Burst Speed to Enter Slide Courtesy Seth Coffman 3. Burst Speed to Exit Behlke et al 1990 12
Passage Gates Passage requirements are: Always met Frequently met Infrequently met Never met Flow Direction Slide Courtesy Seth Coffman
Longitudinal Profile Protocols to Determine Passage 14
Coarse Filter Predictive Models Model A: Salmonidae Salmon and Trout Model B: Cyprinidae Minnow Species and Young-of-Year Trout Model C: Percidae and Cottidae Darters and Sculpin Courtesy Seth Coffman
FISH PASSAGE PREDICTIVE MODEL Greatest fish movement for trout occurs when: Outlet perch less than 4 Slope < 2% Slope x Length < 84 BUT- Try to REPLICATE STREAMBED Fish passage predictive model- Young of year trout. Based on physical measurements from Clarkin, K., et al. 2003.
ANF FISH PASSAGE SURVEYS Surveys of 189 road-stream crossings found that only 72 (38%) are passable by a majority of adult and juvenile fish. 73 are fish passage barriers 44 are possible fish passage barriers
AQUATIC PASSAGE SURVEYS Courtesy of US Fish and Wildlife Service- Lower Great Lakes Office 18
ORGANISM PASSAGE BY WATERSHED - AOP Surveys on 526 culverts in 3 watersheds in PA and NY 140 120 100 80 64 % Passable 25 % Impassable 11 % Partially Passable Passable Impassable Partially passable 60 40 20 0 Brokenstraw Ck (NY & PA) Tunungawant Ck (NY & PA) Courtesy of US Fish and Wildlife Service- Lower Great Lakes Office Great Valley (NY) 19
ORGANISM PASSAGE BY STRUCTURE 80 70 60 50 40 30 20 10 0 ` 198 Culverts with bottoms (200 surveyed) 13 % Passable 60 % Impassable 27 % Partially passable Passable Impassable Partially passable Courtesy of US Fish and Wildlife Service- Lower Great Lakes Office 20
TYPES OF PASSAGE BARRIERS Insufficient water depth Absence of resting areas Outlet Drop Jump Barriers 21
Physical barriers Velocity Barriers 22
TYPES OF PASSAGE BARRIERS Inlet aggradation Outlet Erosion Scour Pool 23
Low Water/Flow Road-Stream Crossing Barriers Box culverts set too high Lack of substrate Structure needs banks to create a thalweg 25
Low Water/ Flow Barriers Discontinuity of channel substrate 26
HOW DO WE IMPROVE? Build structures that: Can accommodate 100 year-flows- Without backwater. Match the bankfull channel width and site characteristics Replicate a reference stream channel site Consider how the stream channel will adjust after culvert installation 27
Streambed Simulation through the Culvert Replicate Natural Stream Channel! Bank Reference channel shape
STREAM SIMULATION DESIGN PROCESS Hydrology Site Assessment Alignment and Profile Bed and Banks Structure Sediment Mobility & Stability
STREAMSTATS FOR PEAK FLOWS Delineates watershed from a point Calculates peak flows for 2 year, 50 year, and 100 year events Uses regression equation or gage site comparison http://water.usgs.gov/osw/streamstats/pennsylvania.html
HYDRAULIC ANALYSES FOR CULVERTS HDS-5 Nomographs Computer Models: HEC-RAS HY-8 FHA Culvertmaster
Site assessment- Get to know the stream system! 33
Floodprone area Bankfull channel Find your reference reach for channel design Bankfull channel width Flood plain width Ecological processes
Stream simulation culvert width Some benefits of structures wider than bankfull width: Banks match reference channel. Minimize inlet contraction during high flow events. Decreases flow or turbulence barriers for fish Can create dry habitat conditions for passage of additional organisms increases openness.
Road Fill Design the culvert to fit Design the channel and floodplain Road Dip Culvert Width Reference channel bankfull cross section Floodplain culvert in flood swale Floodplain
Structure types Bridge Box Pipe Arch Bottomless Arch Embedded Round
Reference Reach ~ 1.2 % Scour, incision or aggrading due to existing structure Channel effects to removal of existing pipe head-cut potential Natural variability of bed elevation Channel restoration extent & feasibility 38
Channel Restoration Outlet Scour Aggradation Outlet Scour
Channel Restoration with Outlet Scour Install a culvert that matches the bankfull width Bury culvert below grade control Use aggraded material inside culvert or to fill scour pool Build a streambed through culvert Grade Control Outlet Scour
Channel Restoration with an incised channel Grade Control Proposed new structure elevation 41
Banks, bands Bands Debris Bank Reference channel shape
Perform a pebble-count in reference reach 43
Bed Material Size Classes from Pebble-count Gravels D100 = 300mm, 12 in. Boulder D90 = 90mm, 3.5 in. D50 = 35mm, 1.4 in. Fines Cobble 44
Bed Material Installation 45
Shingle Mill Bottomless Arch - Building the stream bed and banks. 46
EXAMPLE OF ROUND CULVERT INSTALLATION ON A STEEP SLOPE
SEPTEMBER 2011. SETTING THE CULVERT BELOW THE CONTROL 48
SEPTEMBER 2011. PLACEMENT OF RIP RAP TO TRAP BEDLOAD. 49
FEBRUARY 2012. NATURAL STREAM CHANNEL PRESENT IN CULVERT AFTER 4 MONTHS. 50
SUMMARY More inventory of culverts needed to determine aquatic passage barriers Focus on replacing culvert barriers in priority watersheds 51
SUMMARY Stream simulation benefits Restore access to more streams Decrease failures from flooding Allow for movement of debris and bed material Increased life of structures Leads to cheaper cost 52
QUESTIONS? 53 Credits: Gary Larson, The Far Side