The scheme is a large Flood Alleviation Scheme that reduces the flood risk in an economically achievable standard with ranges established by sensitivity testing.
Please note that component projects will be listed separately as they come into delivery.
Flood risk in the River Hull valley constitutes the biggest single risk in Hull and East Riding in terms of life, health, property, business and long term economic sustainability and viability, it constitutes the biggest natural risk in the region and the represents the second highest flood risk in the UK. Subject to the outcomes of the study it is anticipated that failure to make this investment may lead to catastrophic flooding in this area therefore this represents extremely sound and necessary investment.
The target standard will be 1% Annual Exceedance Probability with a 30% allowance for climate change (1:100 year + 30% CC Standard of Protection). This will be refined with sensitivity testing that shall take into account climatic antecedents and other factors. Subject to detailed options appraisal in line with the Defra approved national standards using the “Flood Hazard Research Centre – Flood and Coastal Erosion Risk Management – A Manual For Economic Appraisal of flood Risk”, the preferred option will include one or all of the following components:
- Construction of large flood storage areas in the upper valley ranging between 2-3 Million m3.
- Construction of new engineered flow delivery and exceedance systems.
- Improvements to channel and flow conveyance
- Installation of Supervisory Control and Data Acquisition System (SCADA) to for level control, pump operation and flow cut off devices
- Improvements to East Hull Pumping Station to give improved presentation of hydraulics from the Holderness Drain
- Various environmental improvements to enhance Water Framework Directive Opportunities
The first stage is production of a Strategy to identify a truly integrated approach to managing flood risk in the natural River Hull valley, building on work already undertaken by the Environment Agency and both East Riding and Hull City Councils. The Strategy takes guidance from the River Hull Advisory Board to ensure all relevant stakeholders and flood Risk Management Authorities (RMAs) are engaged in order that a fully comprehensive outcome can be achieved. The second stage is to implement a construction programme to create new infrastructure in the River Hull Valley.
Work to inform the Strategy will use computer mathematical models to simulate the drainage network and provide evidence of the impact from multiple sources of flooding. Using this as a representation of the real world, strategic options will be developed to identify the best value solutions to manage flood risk, recommending a prioritised programme of investment.