We have had a formal biodiversity duty since 1 October 2006 under Section 40 of the Natural Environment and Rural Communities Act 2006.
The Act requires that when we are carrying out our work, we must "have regard, so far as is consistent with the proper exercise of [our] functions, to the purpose of conserving biodiversity".
This includes restoring and enhancing biodiversity, as well as protecting it.
In addition, we have a statutory duty to protect and, where possible enhance, biodiversity and landscapes of natural beauty under the water industry's Code of Practice on Conservation, Access and Recreation 2000.
The Code gives practical guidance to water and sewerage companies and the Environment Agency on environmental and recreational duties under the Water Industry Act 1991 and the Environment Act 1995.
A wide variety of other UK, European and international environmental legislation also protects biodiversity. The Defra website includes useful background on this legislation.