Yorkshire Water has published a climate change report that highlights how extreme rainfall and storm surges are likely to increase across the region.

In recent weeks there has been flooding in York, Ripon, and areas of Humberside due to very heavy rainfall brought by Storm Desmond.

The report, ‘Adapting to a changing climate’, emphasises how Yorkshire and Humberside has historically suffered from significant flooding, notably in June 2007 which was the wettest month in the region since 1882.  It also draws attention to the increased risk of storm surges along the Holderness Coast and street flooding caused  by heavy rainfall overwhelming sewer systems.

Data from the Met Office shows that the amount of heavy rainfall events have increased significantly over the last 50 years due to the warmer atmosphere being able to hold more moisture.  As a result, heavy rainfall events are likely to happen five times more often in the future, as global warming continues to change our climate.

Amanda Crossfield, Lead Climate Change Advisor at Yorkshire Water, said:

“The report highlights current and future flood risks in the region and what we are doing as a company to reduce these risks. For instance, we are installing flood defences where appropriate but also enhancing our emergency response capacity, and increasing the flexibility of our water distribution grid so we can re-route supplies when required. This means we are taking the most cost-effective approach to managing the flood risk to our assets and to the services we provide customers.”

Since the 2007 floods, the company has invested more than £50m in re-building several flood damaged waste water treatment works and pumping stations, as well as raising critical equipment above the flood depths. Key water pumping stations have also been upgraded with flood walls so they can continue to pump drinking water during flood events.

Storm surges, which involve sea water flooding coastal towns during heavy winds, are also identified as a risk in the report. The shape of the North Sea and the Humber Estuary contribute to storm surge vulnerability as surges tend to “bounce” around the North Sea and get channelled up the funnel shaped Humber Estuary.

In December 2013, the Holderness Coast experienced a storm surge of such severity that it was calculated as a one in 568 year event.

Amanda Crossfield explained:

“In response to this extreme storm surge, we deployed our high capacity pumps to assist the Fire Service in pumping excess water from around the sea front in Whitby, and also ran our emergency storm pumps in Hull which evacuated 35,000 tonnes of water to prevent flooding in the city.”

To lower the future flood risk in Humberside, pumping stations are being upgraded including the £3.6m Carr Lane pumping station in Goole and the £16m pumping station at Bransholme. Once completed, Bransholme pumping station will reduce the risk of surface water flooding for 17,000 homes in the Bransholme and Kingswood areas of Hull.

Amanda Crossfield added:

“Street flooding can also be a problem when sewers reach full capacity and start to overflow but this is something we are working to resolve. For instance, we have invested  £80m in the last five years which has helped remove 385 properties from the regulated sewer flood risk register. We are also working with local authorities across the region to remove surface water from our network and help reduce the risk of flooding.”

Other significant projects Yorkshire Water is undertaking to reduce flood risks include plans to upgrade Butterley Spillway in Marsden, West Yorkshire. This will ensure excess water can bypass the reservoir without harm and also reduce the risk of flooding in the village.

The report sets out Yorkshire Water’s  climate change risks mapped to its customer outcomes and shows the company’s high, medium or low risk profile across three time horizons from now until the end of the century. The scores represent  the risk position in 2020, following implementation of its current five year AMP6 business plan.

Click here to download Adapting to a Changing Climate