FishXing Software: A Tool for Evaluation and Design of Culverts for Fish Passage

Culverts at road-stream crossings have traditionally been designed for hydraulic efficiency to yield the most cost-effective design.  Unfortunately this singular objective often produces many adverse environmental impacts.  Poorly designed stream crossings can interrupt the continuity of stream channels by fragmenting the transport of sediment and organic material and by limiting the movement of wildlife and aquatic organisms.  Currently there are many thousands of culverts installed on fish-bearing streams that deny access to habitat essential for their survival.  Conducting inventories to identify and prioritize stream crossings that block access to aquatic habitat is essential to address this problem.  After identifying a culvert for replacement, designing a new crossing that accounts for stream channel dynamics and aquatic organism passage can be a challenging task. 

FishXing is an interactive software package that integrates a culvert design and assessment model for fish passage.  The software models fish capabilities against culvert hydraulics across a range of expected stream discharges.  Water surface profiles can be calculated for a variety of culvert shapes using gradually varied flow equations.  The program then compares the flows, velocities and leap conditions with the swimming abilities of the fish species of interest. Fish swimming performance and variability within a population is an important input parameter that influences accuracy of results.  FishXing provides an extensive database of swim speeds based on peer-reviewed studies and allows the user to run multiple simulations to assess passage of individual fish with varying swimming capabilities.

FishXing is intended to assist engineers, hydrologists, and fish biologists in the evaluation and design of culverts for fish passage. It is free and available for download at the FishXing website. In addition to the software there is a suite of interactive online presentations and a library of published literature covering fish passage inventory and assessment, culvert design methods, and case examples of fish passage projects across North America. 

This presentation will briefly introduce the software and the hydraulic calculations it performs that differ from standard culvert models, followed by a review of model inputs and assumptions related to fish performance and their influence on results.  The presentation will end with a brief tour of the many resources available at the FishXing web portal.