Standards for Fauna Friendly Culverts


Standards for Fauna Friendly Culverts

Marguerite Trocmé and Antonio Righetti - 2011

Organization: ICOET

Location: Switzerland


Watercourses are the backbone of the Swiss ecological network. They are habitat and migration axis not only for aquatic organisms but also play an important role for terrestrial animals. These natural corridors are often interrupted by unadapted culverts along transport infrastructure. Most of the existing culverts were designed looking at hydraulic needs only, rarely considering animal needs.
The Swiss Association of Road and Transportation Experts (VSS) has been integrating environmental issues in their road standards for more than 10 years. The new VSS-Standard on fauna friendly culverts (SN 640 696) was written by a team of engineers and biologists. The standard sets design specifications to insure all new culverts are appropriate for aquatic and terrestrial fauna. The standard discusses also the retrofitting of existing roads as this is the most common situation. Specifications distinguish new and retrofitted culverts. The standard distinguishes 6 terrestrial fauna categories and 5 aquatic fauna categories, for which design elements may be different. The specialty of this standard is a sustainable development approach, integrating a cost/benefit analysis. Several flow charts guide planners towards the most cost-effective solution using criteria from structural engineering, fauna specifications as well hydraulic and maintenance aspects. The goal is to offer clear technical solutions which are also most cost-effective. This guarantees not only an ideal effectiveness of measures, but as well aims a cost minimization. The paper proposes to present this new standard and the approach it is based on.


Document Type: BMP mitigation design
Project Type: underpass
Infrastructure Asset: existing roadway large underpass medium underpass new roadway small underpass
Fauna: amphibians fish/aquatic organisms medium mammals reptiles small mammals