Velocity Distributions in Streambed Simulation Culverts Used for Fish Passage

Abstract

Stream crossings designed to simulate a natural streambed inside a culvert are commonly used to meet criteria where fish passage is required. Currently, there has been little research that quantitatively examines the flow patterns within these streambed simulation culverts. A model is presented that estimates the percent of a cross section that is within the swimming ability of juvenile fish developed from velocity measurements on first‐generation stream simulation culverts — those culverts with a continuous gravel bed. The model, developed with regression techniques, uses physical and hydraulic parameters including discharge, total cross sectional area, Froude number, and relative roughness, and was tested directly against velocity distributions computed from field measurements and in a culvert design mode. Results were favorable, although larger percentage errors exist, particularly at small flow depths. The model appears to underestimate the percent of channel cross section at or below a limiting velocity, hence it is generally conservative in design mode.

Effects of Substrate on Movement Patterns and Behavior of Stream Fish through Culverts: An Experimental Approach

“…We used the mean water-column velocity to characterize the velocity profile [46]. Velocity measurements were taken along a grid 1 cm above the substrate on 5 × 5 cm planform [14]. We used AutoCad software [60] with the velocity data to map isovels (contours of equal velocity) for a 3.5 m length of the flume located near the center of the 10 m test section.…”

“…However, correctly retrofitting culverts can effectively restore fish passage [13]. Research on how the morphological and behavioral adaptations of fish affect passage behaviors through culverts will provide valuable information that could inform future culvert design, particularly for small fish [1,9,14,15].…”

“…Some species of small-bodied fish exhibit behavioral adaptations that facilitate upstream passage through high-velocity zones by using low-velocity paths. In non-uniform flows, small, weak-swimming fish select paths of low velocity to swim upstream [14,15,33]. For example, flume studies document small-bodied fishes consistently swimming in the reduced velocity zone (RVZ) produced by the culvert wall [33,34].…”

Full Issue PDF Volume 39, Issue 2

“…Stream simulation designs are recognized as more effective in facilitating juvenile and adult fish and other AOP than traditional culvert designs (House et al 2005;Cenderelli et al 2011) or low-water fords (Bouska and Paukert 2011). The premise of stream simulation design is that by creating channel dimensions and characteristics through a road-stream crossing that are similar to those in the natural channel, fish and other aquatic organisms will experience no greater difficulty moving through the Downloaded by [Fondren Library, Rice University ] at 11:04 20 November 2014 Stream simulation crossings are designed to maintain geomorphic and hydrologic continuity with the adjacent natural channel by building a "design channel" through a road-stream crossing structure with gradients, crosssectional widths and shapes, bed forms, flow depths, and sediment size characteristics that are similar to those of a stable, nearby reference channel (SSWG 2008).…”

Velocity Field Characteristics at the Inlet to a Pipe Culvert

“…The velocity filed inside the culvert barrel was examined by Ead et al (2000), House et al (2005), Hunt et al (2011), andFeurich et al (2013), to determine suitable conditions for fish passage. A number of papers have been published on erosion and sediment movement at the culvert outlet.…”