2012: the government launches its second tender process for a carbon capture and storage (CCS) demonstration project in the UK. The White Rose project at the coal-fired Drax power station in North Yorkshire, and a gas-fired Shell power station in Peterhead are selected. As essential utility infrastructure, power stations require robust flood-depth data for flood risk assessment, and appropriate protection.
Time for WHS
WHS needed to complete detailed hydraulic modelling at both CCS sites, to assess flood risk and confirm the suitability of proposed design levels.
In both projects we worked with limited data to model complex river channel and floodplain hydraulics.
White Rose: A site surrounded by a complex system of existing land drains, pumps, sluices and river defences that managed flood risk. Our initial assessment showed that breaching of the River Ouse defences would result in worst-case tidal flood risk.
Peterhead: A site identified by SEPA as being at risk of fluvial flooding from the Den of Boddam Burn, with little aerial survey data, making it difficult to determine flow routes across the site. We generated a custom digital terrain model (DTM) using available topographic survey data to achieve high resolution modelling of the flow routes.
In both projects, our early and continuous liaison with the appropriate environmental regulators, the EA at White Rose and SEPA at Peterhead, was key. Model scope and methods were agreed before work started, assuring the client that the regulators’ requirements were being met.
Result: Both reports were accepted by the regulators on first submission, despite their complexity.
At White Rose our initial risk assessment meant that modelling other mechanisms of flooding was not needed. Our pragmatic approach and assessment method also avoided the Environment Agency (EA) requiring compensatory storage. Both reduced cost and time for the developer.
At Peterhead our early implementation of a custom DTM meant robust modelling, delivered on time.
At both sites our 2D models meant that we assessed design level and flood consequences comprehensively, enabling us to analyse flood risk clearly and recommend a range of suitable cost-effective mitigation measures.
“I would like to say a job well done to you and the team for getting this successfully through. Especially given the stop / start nature of the White Rose project and the lack of data provided”
Senior Consultant, Environmental Resources Management