Oral Presentation International Conference on River Connectivity (Fish Passage 2018)

Fish Passage Considerations though Slip-Lined Culverts with and without Baffles (#39)

Blake P Tullis 1 , Amber H Olsen 1 , Mohanad Khodier 2
  1. Utah State University, Logan, UT, United States
  2. Civil Engineering, Yarmouk University, Irbid, Jordan

Culvert rehabilitation, which typically includes sliding a smooth-walled liner inside an existing host culvert pipe, is often a cost-effective alternative to culvert replacement for many applications where the culvert has reached the end of its useful life.  When a smooth-walled pipe is used to reline a corrugated existing culvert pipe; the culvert flow velocities typically increase, the corresponding flow depths decrease, creating a potential barrier to fish passage, relative to the original culvert flow condition. In an effort to provide some baseline data for fish passage through baffled culvert liners, fish passage behaviors of wild brown trout through prototype-scale 0.61 m diameter, 18 m long smooth-walled, baffled and non-baffled culverts were observed in the laboratory under a variety of culvert slopes and discharges.  The baffles significantly increased the range of culvert slopes and discharges over which the fish could successfully pass. The baffled culvert hydraulic roughness coefficient (Manning’s n) increased 274% (approximately equivalent to corrugated metal pipe values), relative to the non-baffled culvert. 


In an effort to evaluate the effectiveness of computation techniques for baffled culvert design, turbulent free-surface flow conditions through a weir-baffled lined culvert were also simulated numerically using a three-dimensional numerical model utilizing three different turbulence models.  Experimental velocity data, acquired using Particle Image Velocimetry, were used to assess the ability of these turbulence models to predict the turbulent flow characteristics for various culvert slopes and discharges. Comparisons between the measured and computed flow field velocity and turbulent kinetic energy data  resulted in reasonably good agreement, particularly using the Renormalized Group k-emodel, with the resulting undulating supercritical flow profiles, which featured recirculating eddies downstream of each baffle.