Recent surface water flooding in Nottingham in July 2013 ( Source: BBC News )

Following the previous posts on flash flood forecasting, the next step is to investigate how recent advances in the science of forecasting heavy rain shower events could be translated into a surface water alerting tool for responders.

Surface water (or pluvial) flooding occurs when rainfall is not able to enter a watercourse or artificial drainage system and ponds or flows across the surface. In Scotland 38% of flooding impacts are from surface water (National Flood Risk Assessment, 2011). If your house isn’t at risk, there’s a reasonable chance that the road or railway line you use to get home is. Although our river and coastal warning systems are well established, surface water alerting is in its infancy.

There are two key challenges, firstly knowing where and how much water is likely to fall, and secondly knowing what will happen when it hits the ground. To help address these challenges we have set up a research project to develop our surface water alerting capabilities. We plan to put together a pilot tool to enable us to provide surface water alerting for the Commonwealth Games in Glasgow in 2014. Following the Games we will use our experience from this pilot to inform our future plans on wider surface water alerting tools for Scotland. The research work is being funded through the Centre of Expertise for Waters (CREW) and carried out by a consortium of experts from the Met Office, CEH Wallingford and the James Hutton Institute. Details of the project aims and objectives are available on the CREW website.

As well as the science work, a stakeholder steering group has been set up including staff from the Scottish Government, SEPA, Transport Scotland, Scottish Water, the Met Office, Glasgow City Council and the Commonwealth Games organisers. The first step was to ask responders what they wanted from a surface water alerting tool. The group identified that the critical period is the 12-24 hours lead time window. During this period responders can make proactive preparations such as clearing gullies, and make sure their standby teams are ready. With 6 hours to go before an event, responders wanted to know which areas of the city are likely to be affected so they can position resources in the right place, as once flooding starts it becomes increasingly difficult to move around the city. Our challenge is to develop the science to help meet these requirements.

This research project will be running for the next 12 months so check back for further updates on our progress.

Clyde – The Glasgow 2014 Games Mascot ( Source: STV News )