Editing Culvert (section)

==Fish passage==
{{Further|Fish ladder}}
While the culvert discharge capacity derives from hydrological and hydraulic engineering considerations,<ref name="Chanson_book2004">{{cite book|author=Chanson, H. |title= The Hydraulics of Open Channel Flow: An Introduction |publisher=Butterworth-Heinemann, 2nd edition, Oxford, UK |year=2004 |isbn= 978-0-7506-5978-9|author-link= Hubert Chanson}}</ref> this results often in large velocities in the barrel, creating a possible fish passage barrier. Critical culvert parameters in terms of fish passage are the dimensions of the barrel, particularly its length, cross-sectional shape, and invert slope. The behavioural response by fish species to culvert dimensions, light conditions, and flow turbulence may play a role in their swimming ability and culvert passage rate. There is no simple technical means to ascertain the turbulence characteristics most relevant to fish passage in culverts, but it is understood that the flow turbulence plays a key role in fish behaviour.<ref name="Nikora2003">{{cite journal|vauthors=Nikora VI, Aberle J, Biggs BJ, Jowett IG, Sykes JR |title= Effects of Fish Size, Time-to-Fatigue and Turbulence on Swimming Performance: a Case Study of Galaxias Maculatus |journal=Journal of Fish Biology |volume=63 |issue= 6 |pages= 1365–1382 |year=2003 |doi=10.1111/j.1095-8649.2003.00241.x}}</ref><ref name="Wang2017">{{cite journal|last1=Wang |first=H. |last2=Chanson |first2=H. |author-link2=Hubert Chanson |title= How a better understanding of Fish-Hydrodynamics Interactions might enhance upstream fish passage in culverts |url= http://espace.library.uq.edu.au/view/UQ:696033 |journal=Civil Engineering Research Report No. CE162 |pages= 1–43 |year=2017}}</ref>

The interactions between swimming fish and [[vortical]] structures involve a broad range of relevant length and time scales.<ref name="Lupandin2005">{{cite journal|author=Lupandin, A.I. |title= Effect of flow turbulence on swimming speed of fish |journal=Biology Bulletin |volume=32|issue=5 |pages= 461–466 |year=2005 |doi=10.1007/s10525-005-0125-z|s2cid= 28258800}}</ref> Recent discussions emphasised the role of [[secondary flow]] motion, considerations of fish dimensions in relation to the spectrum of turbulence scales, and the beneficial role of turbulent structures provided that fish are able to exploit them.<ref name="Nikora2003" /><ref name="Papanicolaou2002">{{cite journal|vauthors=Papanicolaou AN, Talebbeydokhti N |title= Discussion of Turbulent open-channel flow in circular corrugated culverts |journal=Journal of Hydraulic Engineering |volume=128|issue=5 |pages= 548–549 |year=2002}}</ref><ref name="Plew2007">{{cite journal|vauthors=Plew DR, Nikora VI, Larne ST, Sykes JR, Cooper GG |title= Fish swimming speed variability at constant flow: Galaxias maculatus |journal=New Zealand Journal of Marine and Freshwater Research |volume=41 |issue= 2 |pages= 185–195 |year=2007 |doi=10.1080/00288330709509907|s2cid= 83942063}}</ref><ref name="Wang2016">{{cite journal|vauthors=Wang H, Chanson H, Kern P, Franklin C |title= Culvert Hydrodynamics to enhance Upstream Fish Passage: Fish Response to Turbulence |url= https://espace.library.uq.edu.au/view/UQ:413734 |journal=20th Australasian Fluid Mechanics Conference, Perth, Australia |volume=Paper 682 |pages= 1–4 |year=2016}}</ref><ref name="Cabonce2017">{{cite book|vauthors=Cabonce J, Fernando R, Wang H, Chanson H |title= Using Triangular Baffles to Facilitate Upstream Fish Passage in Box Culverts: Physical Modelling |url= http://espace.library.uq.edu.au/view/UQ:653838 |publisher= Hydraulic Model Report No. CH107/17, School of Civil Engineering, The University of Queensland, Brisbane, Australia |year=2017 |isbn= 978-1-74272-186-6}}</ref><ref>{{cite journal|last1=Wang |first=H. |last2=Chanson |first2=H. |author-link2=Hubert Chanson |title= Baffle Systems to Facilitate Upstream Fish Passage in Standard Box Culverts: How About Fish-Turbulence Interplay? |url= http://espace.library.uq.edu.au/view/UQ:678859 |journal=37th IAHR World Congress, IAHR & USAINS, Kuala Lumpur, Malaysia |volume=3 |pages= 2586–2595 |year=2017}}</ref><ref name="WangChanson2018">{{cite journal|last1=Wang |first=H. |last2=Chanson |first2=H. |author-link2=Hubert Chanson |title= Modelling Upstream Fish Passage in Standard Box Culverts: Interplay between Turbulence, Fish Kinematics, and Energetics |journal=River Research and Applications |volume=34|issue=3 |pages= 244–252 |year=2018 |doi=10.1002/rra.3245|url= http://espace.library.uq.edu.au/view/UQ:719818/UQ719818_preprint_OA.pdf |doi-access=free}}</ref>

The current literature on culvert fish passage focuses mostly on fast-swimming fish species, but a few studies have argued for better guidelines for small-bodied fish including juveniles.<ref name="Wang2016" /> Finally, a solid understanding of turbulence typology is a basic requirement to any successful hydraulic structure design conducive of upstream fish passage.<ref name="Chanson2019">{{cite journal|author=Chanson, H.|author-link=Hubert Chanson|title= Utilising the Boundary Layer to Help Restore the Connectivity of Fish Habitats and Populations. An Engineering Discussion |journal=Ecological Engineering |volume=141|issue=105613 |pages= 1–5 |year=2019 |doi=10.1016/j.ecoleng.2019.105613|s2cid=207901913|url=https://espace.library.uq.edu.au/view/UQ:8e04f63/UQ8e04f63_graphical.pdf}}</ref>