Learning the Lessons of Flooding in York
Historic York has seen a number of flood events, resulting in a range of challenges to be addressed and lessons learned. Steve Wragg, Flood Risk Manager at City of York Council, introduces you to how the city has developed its approach and response to flooding.
The Viking river level recorder in York (named after the hotel it was placed adjacent to, not the cities ancient residents) is unique in that it provides a long history of river level records in the city dating back to the 1880’s, many similar telemetry installations across the country have a much shorter lifespan with only a handful boasting the rich history of data available from the Viking gauge.
The gauge gives residents, businesses and flood risk management and emergency planning professionals the information needed to respond to flood events in the city and learn from their impacts.
The River Ouse in York is formed by the Rivers Swale, Ure and Nidd which drain a catchment of more than 3000km2, rainfall in in the Yorkshire Dales and the headwaters of the upstream rivers cause levels to rise in the Ouse over subsequent days, a well-established network of telemetry informs Environment Agency forecasters and Flood Alerts; Warnings are triggered giving advance warning of flood risk to communities in and around York.
With our partners at the Environment Agency, Yorkshire Water and others, we have developed a range of flood risk infrastructure that reduces the impact of repeat flood events and further investments are planned. In addition to this we are working with wider partners to begin the long process of appraising and implementing whole catchment measures that will make our city and many North Yorkshire neighbours resilient to future events.
The cities current flood defences date back to the late 1980s and were completed in the early part of the next decade, lessons learnt from the 1982 flood led to their development. They comprise a mixture of earth flood banks and raised flood walls with flood gates forming access points through the walls at many locations along their length. In addition to this a number of key locations are defended through the installation of temporary barriers and the utilisation of property flood resilience measures. These locations were not included in the original development of flood defences for a number of reasons – a relatively infrequent risk of internal property flooding, the difficulty in engineering defence solutions or the way in which large raised defence structures would have severed homes and businesses from our rivers and the riverside benefits that they enjoy through the majority of the year when river levels are benign.
Long established, tested and implemented flood response plans are in place for the Environment Agency, Yorkshire Water and City of York Council with specific triggers aligned to the escalation of alerts and warnings, many of these reference levels at the Viking Recorder. This is well supported by the rainfall and river level telemetry data upstream of York and forecasting that predicts peak river levels several days before the impacts are felt in the city.
The councils Emergency Planning Unit coordinate the delivery of each plans actions and a number of key services across the authority – highways, communications, transport, public health etic – deliver actions and key roles to ensure the plans are implemented. Links to the North Yorkshire Local Resilience Forum and localised command and control groups are formed as the flood levels rise, all partners work together to deliver a coordinated response to the event.
Our residents, businesses, partners and all council departments have learnt from a number of key flood events in the past. The November 2000 flood was the biggest on record on the River Ouse in York, existing defences were tested and a number of locations were identified where defence improvements were needed to manage a flood of this magnitude. More than 400 properties were flooded on this occasion.
Two significant floods hit the city in September and November 2012, both led to flooding in a number of communities but major impacts were avoided through the actions of the cities defences but areas around the temporary barriers had to be evacuated. Our evacuation procedures were tested and reviewed, operational delivery of temporary defences was refined and best practice was developed to steer future flood communications across the city.
The Boxing Day 2015 flood led to the second highest levels ever recorded on the river Ouse but the highest on record for its major tributary, the River Foss. Again the cities defences contained the majority of the flood risk – it is believed that more than 7000 properties are at risk of flooding across the Ouse and Foss catchment in York but just over 600 properties were affected in the event.
Although the defences performed well in the event concerns were raised over the fact that they had been severely tested for the third time in several years and the peak annual maximum flood levels at the Viking Recorder show a steady upward trend. Our defences built in the previous century were being tested with more and more regularity and their design levels set before a full understanding of climatic change are no longer as resilient as previously considered. As indicated above a programme of improvements has been identified and funded and works are underway at various locations across the city.
In addition to the work to attract funding and future defence improvements an independent flood inquiry was commissioned to explore the way in which the council and other partners were prepared for and responded to the event. More than 90 recommendations were made and have been progressed by the council and all partners to learn lessons from the event and to improve future responses.
Like earlier floods in the city a range of reoccurring aspects of the response were investigated including the way in which operational teams mobilise, communications between partners and to the public and businesses and the effectiveness of the recovery process following the event. However, even with reoccurring themes and areas of response to consider it is important to evaluate what happened during each specific event as we are only as effective as our last set of responses and we can learn from each and every outcome, however, there were a number of specific issues that arose during the event.
The timing of the event during the Christmas and New Year period would test any responder due to resource availability during a holiday period. However, horizon scanning can enable responders to predict the need for additional resources and ensure rotas are aligned to the need. The forecasting for the event was difficult and did not fully predict the severe impacts that were to arise, all partners had to mobilise quickly due to the escalating situation and this did place teams under pressure during this period, however, the response was effective from all partners in the circumstances.
Significant loss of communications infrastructure was experienced in the event, flooded installations in York and Leeds affected phone and internet provision for many in in the city including those responding to the event. The reviews have identified the risks and relevant organisations have acted to safeguard their operational infrastructure in future events. However, the loss of communications did not only affect those at risk of flooding or working in response to the risk, the vast majority of the city was not on flood alert and were not directly threatened by flooding. For many the period between Boxing Day and New Year is a time of holiday and many gravitate to the city centre for shopping or leisure and as a major tourist attraction many visiting York come from afar swelling the numbers wanting to access the city. Cash machines and card payment systems in the majority of retail outlets across the city were affected which had a serious impact on business owners and those visiting the city centre at this time.
The city was lucky enough to be inundated with a significant influx of volunteers who wanted to assist in flood response, recovery or donate and provide supplies and goods to those who had been affected. This level of volunteering was far greater than anything we had experienced before and although it was an extremely welcome aspect of our response and recovery work it required significant management to ensure the volunteers were used appropriately and that their safety and welfare was considered. The community voluntary sector in York played a vital role in this work alongside the council and this has been formalised following the inquiry to ensure better coordination before, during and after future flood events.
A reoccurring theme of flood events in York dating back to the 2000 event and subsequent emergencies has been the way in which visitors to the city view the extent of the impact of flooding and how it will prevent them being able to continue with planned visits. Hotel occupancy in York remains high throughout the year with average annual occupancy around 80% in recent reviews, however, these levels dropped off significant after the 2015 flood event as people were fearful of the risk of flooding and how it could affect their stay. In reality the at risk locations of the city represent a relatively small geographical area and this perceived perception of risk invariably gives people an unfounded view of the likely impact. The vast majority of the city centre is not at flood risk and although a number of roads were affected during the event the majority of key arterial roads into the city were not affected. Messaging around the city being ‘open for business’ or similar has been a regular aspect of our flood recovery over the years, this is essential to support and safeguard the businesses in the city that can be affected by visitor confidence during and after flood events.
We also learn from each event on the way in which our residents adapt their travel plans during periods of flooding. We have reviewed the information on our website and social media platforms which detail impassable roads, changes to public transport routes and wider travel advice, signage is deployed throughout the city during flood events to support travel plans and warn of flood hazards. A review of all signage has been carried out and funding has been targeted to deliver the outcomes, opportunities are being considered to incorporate smart technologies into these works.
Further flood events in 2020 and 2021 have again seen the cities defences perform well but further indicate the need to continue the deployment of formal defence improvements and work has begun to consider the way in which the temporary defence measures can be adapted to optimise their performance and simplify their deployment during an event to provide community flood resilience working alongside property flood resilience measures. The events have highlighted that although their impacts were minimal the regular reoccurrence of flood levels requiring an increased frequency of defence deployment continues to stretch the resources available within the council and partners, the winter timing of the event also draws on a centralised pool of resources that are also dedicated, within the council at least, to winter road treatment during icy and snowy conditions.
Our consideration has now turned to the long term sustainability of our current defence measures and how we can safeguard the protection they bring for future generations. As part of our review of all major floods we work with all partners to speak to at risk and affected communities to review the event and identify their concerns and feed this into future flood resilience planning. Like many across the flood risk management sector our communities want us to embrace catchment scale management of flood risk and the uptake of natural flood risk management measures. We are working closely with partners to identify how we can make this happen and deliver a range of interventions upstream of the city that will work alongside our existing defences and provide long term flood risk benefit in the city and within other communities across the catchment.
Our work in York to manage flood risk to communities, businesses and our visitors is informed by a long history of flood events. The city benefits from a wide range of measures at present but recent history has shown that we cannot stand still and there is a constant need to learn from each and every event and work in partnership to deliver the required improvements and solutions. Be it improved communications, resilient transport networks, improved defences or advice and support for our communities and businesses after an event everything we do in the city is underpinned by the provision of effective and reliable flood risk information from the network of gauges and telemetry across the River Ouse catchment. The Viking Recorder is central to all of this, it has served the city for well over a hundred years and will hopefully continue to inform our flood resilience planning for many years to come.
Flood Risk Manager, City of York Council