- 30th January 2020
- Posted by: Emilia Gates
- Category: Blog
The case for delivering well-designed and integrated blue and green infrastructure (GBI) in the UK has never been stronger. It plays a crucial role in supporting cohesive, healthy, and vibrant communities, viable local economies, attractive landscapes, clean water, clean air, improving biodiversity, natural and cultural heritage, air temperatures, and carbon storage.
This has been underpinned in the UK by government policy, including the National Planning Policy Framework (NPPF) and Planning Policy Guidance, the Government’s 25-year Environment Plan and the emerging Environment Bill. Green and blue infrastructure helps to meet statutory obligations under the Water Framework Directive and Habitats Directive, and will be hugely important in meeting new requirements on Biodiversity Net Gain. The declaration of a climate emergency and development of Climate Change Strategies by many public bodies enables the case to be made for GBI to contribute to climate change adaptation. Increasingly, the benefits to health are being recognised by organisations such as Public Health England and the NHS, with calls for ‘prescribing nature’ to promote both physical and mental wellbeing.
At the same time, natural capital approaches are starting to open up new funding opportunities, and the economic boost given by GBI is better recognised. And the inclusion of SuDS in Sewers for Adoption 8, due to be released in 2020, will provide a mechanism by which some ‘blue infrastructure’ can be adopted by water companies.
Delivery of blue and green infrastructure is achieved through either provision within new developments, or through public realm improvements and regeneration in existing urban areas. In both instances, aside from a few exemplar sites and schemes, experience suggests the ‘blue’ and the ‘green’ elements can often become disconnected.
In new developments, ‘green infrastructure’ is guided by local planning policy and usually considered at an early stage in the master planning of the site, with layout and location primarily based on designing public spaces and sustainable transport corridors into the landscape/townscape. In England, the ‘blue infrastructure’ part is dealt with through the implementation of sustainable drainage (SuDS), with the Lead Local Flood Authority (LLFA) as statutory consultee. The national non-statutory technical standards for SuDS (and hence many designers and approvers) tend to be very focussed on drainage and water quantity, and pay lip-service at best to water quality, amenity and biodiversity value of the SuDS features.
Experience suggests it is still quite common for developers, particularly on smaller sites, to consider ‘blue infrastructure’ quite late in the site design process, a product of the days when surface water could just be piped and stored underground, unaffected by the site layout or even topography to some extent. All too often, this results in costly and unwelcome late changes to design or land-take to try to meet today’s SuDS requirements. If SuDS have to be ‘shoehorned’ in to the pre-planned green space at a late stage, they are less likely to be as effective in terms of their drainage function, or fulfil their potential to provide multiple benefits.
Projects to improve green infrastructure in existing urban areas can often also lead to a disconnect of the ‘green’ from the ‘blue’, with projects to add greenery into the streetscape sometimes resulting in missed opportunities to utilise surface water to irrigate the vegetation and trees, clean polluted highway runoff and slow the flow to surface water or combined sewers . Limited budgets may play a part in this, but partnership working with water companies, LLFAs and Highways Authorities at an early stage may identify funding and cost-saving opportunities.
More water sensitive designs can be achieved by earlier consideration of ‘blue infrastructure’ though a multi-disciplinary design approach. If we can ask the question ‘where will the water go?’ during early design, landscape, visual impact and public realm/green infrastructure planning, we can help developers to understand the amount and location of land that may be required for blue infrastructure at an early stage. Similarly, if drainage engineers understand how SuDS can contribute to landscape, biodiversity and green infrastructure requirements, they can deliver efficiencies by integrating blue and green, optimising land-take and efficiency of design and delivering maximum possible benefits.