Highway stormwater detention ponds as biodiversity islands?

Abstract

The European Directive on urban wastewater treatment voted in 1991, compelled industries to deal with their wastewater. As a result, highways companies had to dig stormwater detention ponds alongside roads mainly in order to catch and treat road runoff. These stormwater ponds were quickly and largely colonised by aquatic organisms while they were only designed for a technical purpose. But if many of them have been dug all over Europe, their use by wildlife remains poorly studied. This article aims at taking stock of the role of highway stormwater detention ponds for biodiversity by (i) reviewing the knowledge on the chemical contamination found into it and (ii) addressing the problem of the use of these stormwater ponds by wildlife. The discussion is based on a survey conducted during one year (2002-2003) on six highway stormwater detention ponds situated in south-eastern France.