Integrated Green Grey Infrastructure+Green River Engineering

21 November 2017

This webinar follows on from the launch of the NERC funded Green Infrastructure approaches in fluvial, coastal, urban and historic environments presented in April 2017 (given by a range of speakers led by HR Wallingford and University of Glasgow). 

Working together with natural systems provides a range of benefits to society, from reduction of climate change impacts and protection against floods and environmental disasters to carbon storage, clean water and air. This idea has led to the concept of Green Infrastructure (GI): a network of natural and semi-natural features that intersperses and connects villages, towns and cities. For many reasons, however, much of UK’s infrastructure does not currently fit with the description of GI. To address this shortcoming, two NERC funded projects were set up to highlight innovative measures that include or improve GI in and alongside grey infrastructure and to help decision making. These projects will point to innovative opportunities to alter practices, change methods or select different materials to include habitat in new build, repairs, improvements and to retrofit.

On watercourses, there is a pressing need to better understand the performance of green engineering bank stabilisation measures: to understand their whole life performance compared to hard engineered solutions. There is also a strong legislative framework that drives the need to protect and enhance the environment, from European and UK legislation such as the Water Framework Directive 2000, Flood Directive 2007 and the Flood & Water Management Act, 2010. The European Commission is also committed to developing a GI Strategy to help to achieve the Europe 2020 objectives. GI solutions include green engineering measures and greening grey river engineering assets with equivalent or increased benefits compared to conventional “grey” infrastructure. Green measures can become self-regenerating and represent a long-term solution that also promotes biodiversity and amenity value.

Case studies of past schemes from across a range of river typologies were revisited to better understand how they have performed from both an engineering perspective and ecosystem services benefits.

On the coast, there are many opportunities to enhance “grey” linear coastal and estuarine flood alleviation and erosion protection assets to create ecological niches that deliver outcomes for the environment and society. In some cases there is also the opportunity to reduce the rate of deterioration. All too often these chances are overlooked but as sea levels rise, habitat opportunities further up the tidal column will become increasingly important. This research has looked at existing case studies to establish how they have performed and what added benefits they provide. 
In urban and historic built environments there are opportunities to green grey non-building assets (bridges, freestanding walls and street furniture) to improve their multifunctionality; providing habitats can improve sustainability, reduce short, medium and long-term costs, improve aesthetic appeal, resilience and a host of ecosystem services to improve chronic urban problems. Other opportunities include using nature on or around our historic buildings to help maintain monuments. The work produced from both projects will help designers, commissioners and government agencies identify opportunities to include green measures and examine them against a number of critical success factors. This will help to determine to what degree they can be included as part of a comprehensive business plan that includes budget and economic benefits, engineering performance and environmental services such as ecosystem enhancement and amenity value.