Skip to main content


Friday 13 Mar 2020Is valuing blue-green-infrastructure beyond our ken?

Prof Richard Ashley - University of Sheffield

Harrison 103 14:35-15:25


There is an unseemly rush to monetise everything. Since the millennium ecosystem assessment at the turn of the millennium, ecosystems and natural systems have been fair game for monetisation. There are now numerous and various valuations of BGI and almost as many different models for doing this. Few have been standardised or even peer reviewed. Almost all are based on ecosystems services valuations and the service provided by the environment to humanity. But how real are the results? Do 100 trees provide 100 times the financial value of one tree? The talk will be based on the development and application of the CIRIA BEST (benefit of green infrastructure) tool, referring to the now numerous case studies. It will illustrate the chimera that is economic valuation of nature, an approach only being undertaken as ‘sustainability assessment’ has proven to be beyond humanity’s ken. Where then should we go? Some ideas as to what we should be doing (but won’t) will be presented.


A Professional Chartered Civil and Environmental Engineer and former MD of the Pennine Water Group (PWG) at the University of Sheffield. Director of EcoFutures Ltd.; researcher in flood resilience at IHE in Delft, Netherlands; Adjunct Professor at Lulea Technical University, Sweden. Recipient of the IWA/IAHR Joint Committee on Urban Drainage 2014 triennial Career achievement award and 2008 IWA award for research into sustainable water systems. Richard has worked in practice and has a research career spanning more than 50 years in the design and science of urban drainage systems. In the last 20 years he has worked extensively in cross-disciplinary activities in SuDS, playing a key role for the Welsh Government in implementation of Schedule 3, and as a co-creator of CIRIA’s benefit valuation tool BEST. He also was part of the IHE team bringing flood resilience into WSUD in Australia. In 2018 he led a review of the future needs for water and wastewater infrastructure in EU member states for OECD and DG Environment and is participating in several EU projects on blue-green infrastructure and asset management. He has some 600 publications, with many significant research findings mainly for urban drainage and flooding.

Add to calendar

Add to calendar (.ics)