Design considerations of hydraulic structures

There are thousands of hydraulic structures within the river and canal networks of the UK. Richard Chubb, Associate Director and Delivery Manager for our Collaborative Delivery Framework with the Environment Agency examines some of the key design considerations when delivering new, or reviving existing, assets.

For thousands of years civilisation has been modifying rivers and watercourses to benefit society, be it the harnessing of its natural energy to drive mills, the creation of canals to form the motorways of the Industrial Revolution, flood defences to protect communities and more. Living in East Anglia, it is perhaps more evident to me here than anywhere else in the UK how much of the natural river basins have been modified, with the help of our Dutch friends, of course. Therefore, when designing new hydraulic structures or refurbishing existing ones, understanding its functional need and the job that it is to perform becomes one of the most important things to determine and agree with asset owners. 

Often these structures have multiple functions. For example, a sluice that controls water levels for navigation could also be part of the flood defence system. It may also be important to managing low flows during the drier, summer months to maintain water quality. Key to determining these fundamental principles to a project is good consultation with all relevant stakeholders, coupled with a sound understanding of the hydraulic system, including the influence of other structures and controls in the watercourse.

Operational considerations

Many existing hydraulic structures in the UK are close to the end of their technical or functional life. The costs of continuing to maintain and operate these assets need to be weighed up against the investment of a new one. Other factors are also important, including how safe the asset is for operational and maintenance staff, its sustainability in terms of energy use and the carbon cost of future refurbishment, and whether mechanical and electrical elements are still supported to ensure spare and replacement parts are available if required.

Frequently with older structures the enabling costs for safe access far exceed the actual cost of the maintenance required and this has led to the deterioration of the assets to a point of capital projects being required.

Denver Sluice Little Eyes, Norfolk
Denver Sluice Little Eyes, Norfolk

Therefore, the use of low maintenance materials for wearing parts such as bearings, provision of access facilities and incorporation of stoplogs into designs are all considerations for remote locations or those with poor access.

A continuous programme of asset inspections is invaluable to provide the evidence often needed when hydraulic structures start to fail, to help identify the best solution. Indeed, a good asset inspection and management programme will identify issues and investments needs well in advance that should avoid any failure at all. In some critical operational assets there may be justification for condition monitoring of key equipment to identify trends in performance and use evidence based maintenance techniques.

Whole life assessment

Climate change will have an impact on hydraulic structures, particularly flood risk management assets. Increasing sea levels and more extreme weather events may require existing assets to be adapted to provide maintain the standard of protection. Some assets may not be able to continue to function as designed, such as tidal sluices where pumping solutions may be required to drain inland watercourse. Assets may be required to operate more frequently than anticipated, which may affect their reliability and performance if left unchecked.

A full understanding of what new and existing assets are going to be required to do over the whole of their lifespan is so important to be able to make the right decisions in asset management. Coupled with a sound understanding of an existing asset’s condition and operational issues or needs, a whole life cost and carbon assessment can be undertaken to identify the best solution.

Technological advancements and collaboration

Orton Sluice, Cambridgeshire
Orton Sluice, Cambridgeshire

When delivering solutions there are other aspects, and opportunities, to consider. Ensuring operational safety is key to the design process and getting direct input from the end user is invaluable.

The use of 3D visualisations and virtual reality are now available and can help to capture the space and access requirements for undertaking operational and maintenance activities, which can then be allowed for in the design.

Other aspects are important, such as any security rating for the asset, energy and carbon use, future budgets for adaptation, or otherwise. The success of hydraulic structure design lies in the collaboration of all the relevant stakeholders to determine all the requirements whilst the solutions are on the drawing board, which provides huge value further down the line. 

Want to know more? 

JBA has wide ranging experience in delivering solutions for new or existing hydraulic structures, using the latest technology to collect information and data and complete the design and consultation process.  Email our author Richard Chubb or co-author Eric Biggadike for more information. 

You can also find out more on our webpage.

 



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