Paul McIlroy / Flood gates / CC BY-SA 2.0
The first couple of months of this year saw a number of major flood events making headline news. These have now been superseded by coronavirus (on which look out for next month’s blog), but they had devastating impacts on our urban and natural environment, and of course also on people’s lives. And, as climate change experts have advised that such events will become more common in the future, there is increasing pressure for more measures to be introduced to protect people’s homes and livelihoods.
Flood mitigation schemes are often (but not necessarily) major civil engineering projects, and so a balance needs to be found between providing an appropriate level of protection and introducing such interventions into often sensitive urban and rural landscapes without damaging those. We were particularly conscious of this when, earlier this week, we caught up with a friend who was involved in the design of the Perth flood protection scheme.
For those not familiar with it, the Perth scheme was delivered in response to extensive flooding in 1990 and 1993, and was completed in late 2001. This comprises direct defences from Inveralmond to Friarton, including the North and South Inches, Tay Street and the harbour area, as well as other primary and secondary measures. These include extensive measures to ensure public acceptability, such as the introduction of public art and maintenance of existing access to the river. This then got us thinking, from a planning perspective, about what can be learned from our friend’s experiences in Perth and applied to new projects to ensure that, in addition to fulfilling the primary aim of flood risk reduction, they make a positive contribution to the urban realm in which they are installed.
The Perth scheme was the largest flood prevention project of its kind in Scotland at the time it was conceived and constructed, incorporating 10km of walls and embankments at a final cost of around £25million. Perhaps not surprisingly, there was a challenge around the level of investment required but, like all flood prevention schemes at that time, the Flood Prevention (Scotland) Act (1961) required this to demonstrate a positive cost benefit analysis, evidencing that the financial benefits of the scheme would outweigh the capital costs.
The scheme runs through the heart of the historic centre of Perth and encompasses two public parks, so delivering a publicly acceptable scheme that enhanced the natural and built environment while still effectively mitigating the risk of flooding was a key challenge for the project team. A fundamental aid in this regard was the allocation, by the Council, of specific funding for public realm enhancements to Tay Street, which meant that engineering solutions could be devised and implemented which would not otherwise have been possible. This included, for example, raising the pavements on Tay Street, incorporating hiqh-quality ashlar stone and Caithness paving, and introducing stainless steel railings to allow the flood prevention walls to be lowered such that the link between the public and the river would be maintained.
But the vision of the Council for the scheme went further still and, significantly, the Council commissioned what have become iconic bronze flood gates, as well as stone sculptures which now form part of the River Tay art trail. Significant effort also went into the treatment of the high embankments along the North Inch, creating a tiered embankment with shallow slopes that is not readily identifiable as a flood defence scheme.
Importantly, these works were informed by extensive public consultation to allow the project team to share their ideas on the scheme layout and how the works would be finished, and to understand what would be acceptable, with this process led by the planning authority. This public involvement continued through to construction and, for example, where some historic lime trees had to be cut down to accommodate the Perth scheme, members of the public were allowed to take away pieces of these trees, addressing concerns about the loss of these in a very personal way.
With advances in digital technology, engineers and their clients can now call upon a range of digital media to engage with the public, rather than just artists’ impressions as were used for the Perth scheme. For example, apps, interactive 3D images, augmented reality and collaboration platforms can all be used where appropriate, particularly for larger schemes, to properly allow people to understand, visualise and provide feedback on what is proposed. At the same time, the need for face to face engagement is still paramount, and it is important to consider the potential to involve people in ways that go beyond just consulting them on how a proposed scheme looks.
Perhaps the biggest takeaway from the Perth project though is the role the Council played in terms of recognising the visual amenity of the existing area and the need to not only mitigate potential environmental impacts, but to use this as an opportunity to provide betterment for the City of Perth. And it is that more holistic approach to flood prevention planning which we think is crucial to such measures contributing to creating great places. New flood prevention schemes should not be designed in isolation, but rather opportunities should be taken to combine them with public realm or other public benefit schemes, which would not just maximise the benefits of the investment but also ensure that one does not prejudice the other.
Helpfully in this regard, schemes brought forward these days are done so under the Flood Risk Management (Scotland) Act 2009, which now allows both cost and social benefit to be considered when assessing financial aspects. This means that local authorities can take account of wider amenity and social benefits of a scheme when considering whether or not to progress with it, rather than merely the engineering aspects. The holistic approach, for which the Perth scheme was a forerunner, is being embraced elsewhere in towns such Hawick and Whitesands, and we look forward to seeing the outcome of these projects.
Meantime, to find out how we can help with any aspect of the planning process, please visit our website or email us at info@auroraplanning.co.uk. If you would like to keep up to date with our blogs and bulletins, sign up using the form below.
Thanks for reading!
Pippa and Maggie