The UK is criss-crossed by many rivers that host a wide variety of flora and fauna. Between their constant use by vessel users and their importance to natural ecosystems, keeping them in good condition is a priority.
The role of river management and river maintenance is therefore vital in England and Wales, and Scotland and Northern Ireland. Consequently, river contractors like The Rothen Group (TRG) carry out maintenance programmes to control canals and rivers and manage flood risks.
While there aren’t river builders, marine civil engineering is used for river maintenance and risk management. In this article, we have identified key questions around river management, and provided answers.
How do you control a river or waterway?
Rivers are naturally occurring channels host to constantly moving volumes of water. As such, there are no river builders in a conventional sense. They are ‘made’ through rainfall and naturally occurring water sources eroding land over extremely long time periods.
While river design is initially determined by nature, river management helps shape waterways to our needs. Indeed, river contractors have been instrumental in curbing wear and tear that can lead to natural disasters. This can include anything as minor as a riverbank collapses, to major events like river flooding. It can even mean the creation of synthetic river valleys.
Especially with climate change in mind, flood management and flood defence are major motivators behind controlling rivers and waterways. This control can come in the form of large-scale projects like dams, which require ongoing maintenance.
Alongside this, there is also ongoing soft engineering and hard engineering work. Such a combination of approaches is instrumental to river maintenance. When implemented properly, they help mitigate issues such as leaks, which could have a serious environmental impact if left unchecked.
Controlling waterflow within rivers has been important for thousands of years, not only to avoid flooding but also to take advantage of the benefits the flood plain can provide and the supply of water. Since Ancient Roman times and the Yuan Dynasty, rivers have been used as an important resource, although in more recent years the focus of river and waterway control has shifted towards environmental concerns. As a result of global warming and the poor maintenance of many waterways, there is a growing risk of flooding, so it is more important than ever that an effective management program is followed.
From the hydraulic civilisations along the Nile and Indus Rivers, humans have relied on river maintenance and control for water security, energy, transportation, housing, wildlife, and ecology, this is why river maintenance is so important. As climate change continues to impact temperatures, rainfall and water levels, water supply and flood risk management is clearly important for our economic, social, and environmental wellbeing.
How can rivers be managed using hard engineering?
Hard engineering is a form of river management using artificial methods to control naturally occurring processes. Piling, for example, is invaluable to river management and maintaining flood defences. It consists of driving post-like objects into the ground along the riverside to support structures like retaining walls.
Specifically, these constructions support riverbanks that would otherwise erode over time due to contact with the constantly moving river channel. If these banks were to collapse or burst, the environmental impact caused by the resulting floods could be huge.
Hard engineering processes like dredging ensure greater volumes of water can be held in a river channel, further reducing flood risks. Repeated dredging is necessary due to the constant build-up of sediment and debris on riverbeds over time.
It involves the removal of this material via dredger boats and excavators either on land or on floating pontoons. By taking away this sediment, higher volumes of water flow through pressure points in waterways, keeping river levels low.
There are many areas which need to be managed within any river or waterway, such as the following:
Building hard engineering structures such as dams, embankments, and reservoirs to protect areas within a floodplain.
Modifying the flow of the river through techniques such as straightening the channel or making it deeper by dredging.
Restoration and protection of important wildlife areas, such as natural wetlands.
Managing drainage channels within areas of low-lying, fertile ground such as the Fenlands.
Restoration of winding courses and natural floodplains, so that floodwater is released gradually.
The removal of obstructions from the river course, such as tree roots, rocks, gravel accumulations and plant growth, which could impede water flow.
Natural flood management through the planting of trees, small wood dams and by storing water within open land.
Hard engineering is often used to manage rivers, with artificial structures such as embankments and dams used to control water flow. For example, dams can be used to trap water within a reservoir, so that water can be released in a more controlled way, and it is even possible to produce electricity from the force of the water as it passes through the dam.
What are the main types of river/waterway management?
As previously stated, river management can be broken down into soft and hard engineering. Soft engineering is a form of river maintenance that emphasises environmentally friendly practices. It is often used to restore waterways that have become degraded over time through overgrowth or a lack of maintenance.
Examples of soft engineering include using organic solutions as a form of erosion control, including coir rolls. Composed of coir made from coconut husks compacted into bales, these eco-friendly solutions make a dream home for aquatic vegetation.
Coir rolls can offer a supportive bank barrier that also helps restore river-based habitats and ecosystems. This is especially true when used in front of Nicospan bank protection (a membrane strengthened by covariant structures in the material). This is due to the Nicospan coating, which is made of UV-stablised yarn, having an ‘open pocket’ structure. As such, plants can grow through the material without compromising its structural integrity, bolstering riverbanks in ecologically sensitive areas.
Our rivers are a precious resource that we rely on for everything from fishing and agriculture through to tourism, ecology, wildlife, and infrastructure, so it is vital that they are managed effectively. We cannot live without water, and throughout the UK there are various organisations, businesses, charities, and volunteers involved with the management of our rivers, canals, estuaries, wetlands, and coastal areas, including the team here at The Rothen Group.
Organisations such as TRG on behalf of local authorities, the Environment Agency and other river trusts. For more information, please call 01827 215715 or email info@therothengroup.co.uk.
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