DREDGING

The Rothen Group, as specialist waterway and civil contractors, work on behalf of the Canal River Trust, Environment Agency and private waterway owners to perform this vital service that keeps canals and rivers navigable, and their natural ecosystems intact.

 

No two types of project in this area are the same, which is why dredging contractor expertise is necessary. Services can involve maintenance dredging on a weekly, monthly or yearly basis in specific areas prone to debris and sediment build-up. This can include around bridges and channels feeding into the canal, as well as widened areas used to turn boats, also known as winding holes.

 

Alongside this, more sporadic main-line maintenance dredging may take place, which involves working on a stretch of canal mile-by-mile over a longer period. In both instances, this usually requires the use of excavators either on the water or on the canal bank to collect debris from the canal bed.

 

The cost of dredging canals can vary depending on the amount of dredging equipment used, and the complexity of the project. For example, the width and shallowness of a canal may necessitate narrower boats and pontoons, with shallow drafts. The structural integrity of the canal bank may also make using land-based canal dredging equipment impossible, so a different approach may be needed.

 

Consequently, specialist marine engineering companies like The Rothen Group use multiple types of canal dredging equipment to keep our UK canals clear. This includes a fleet of unique modular pontoons and floating dredger boats for use on the water, and long-reach excavators that can work from the bank side.

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We have extensive experience in carrying out all types of dredging on inland waterways. Contract Services Our proactive, knowledge based approach ensures even the most difficult canal or river dredging; of moorings, winding holes, bridges, non-navigable waterways, attenuation features or lakes can be undertaken.

 

We have a range of floating plant and machinery to accommodate any sized site and facilitate removal by water or road to deposit sites for drying and reuse as topsoil or compost. We are more than happy to discuss your needs and undertake a site visit free of charge, to assess the best approach for you. Using floating dredgers, modular pontoons or long reach excavators, we can accommodate your project needs. In addition we are fully licensed to dispose of your material in a cost effective manner which ensures low environmental impact.

 

Dredging plays a crucial role in ensuring the navigability of canals and rivers by removing sediment, debris, and other substance build-ups from the water. The primary purpose of dredging is to maintain a sufficient water depth, allowing boats to safely pass through waterways. By removing accumulated materials, such as mud, rubbish, debris and silt, regular dredging will prevent blockages that will impede navigation and contribute to flooding issues.

 

As specialist waterway and civil contractors, we work closely with organisations such as the Canal & River Trust, the Environment Agency, and private waterway owners to deliver an essential dredging service that is also considerate of the waterway ecosystem.

 

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How is dredging a river done?

 

Dredging is the removal of debris, litter, organic sediments or other unwanted substances from a body of water. It is done for a number of reasons, and sometimes the dredging of a river or canal is needed to keep the water safe for boats to pass through. 

 

Some methods, like suction dredging which is done to search for gold, damage the immediate environment. Other times, canal dredging can be for environmental reasons, as build ups of dead plants or other debris can negatively affect the ecosystem of the area. The Rothen Group (TRG) uses environmentally friendly methods to clean waterways.

 

Every dredging project is unique, requiring expert knowledge and tailored solutions for weekly, monthly, or yearly dredging. For example, regular dredging maintenance is useful when targeting specific areas that are prone to debris and sediment build-up, such as bridges, channels, and winding holes. This proactive approach ensures the continuous flow of vessels and helps to prevent localised flooding. 

 

In addition to routine maintenance, we also undertake sporadic main-line dredging projects, mile by mile, to remove sediment accumulation over longer stretches of canals and rivers. There are also situations where capital dredging is required to deepen or widen waterways, especially within rivers that have not been dredged in many years. 

 

As you can see, dredging is completed for a variety of reasons, including:

 

• Navigation – Dredging ensures that waterways remain deep and wide enough for the vessels using the waterways. By removing obstructions commercial boats, leisure crafts and other waterborne activities can use the water safely.

 

• Flood risk reduction – Regular maintenance dredging will reduce the risk of localised flooding by increasing the water-carrying capacity of rivers and canals. A waterway with a build-up of excess sediment and debris will be at risk of overflowing during heavy rainfall, so it is important to adopt a proactive approach.

 

 

• Preserving ecosystems – Dredging can be used to maintain the ecological balance of waterways, as the removal of excess debris and sediment can improve water quality allowing animals and plants to thrive. Careful dredging can also help to preserve the health of the ecosystem by preserving natural habitats of important species and preventing the accumulation of toxic gases.

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Removing Material Buildup

 

As canals and rivers flow, they carry material from one place to another. Ideally, these materials will be beneficial to the environment like nutrients for plants and fish, or moving organic waste towards the sea. 

 

When materials build up too much it is important that those responsible for the canal or river (or the pond owner) arrange for the water to be dredged. Combined with litter or other pollutants, it can be easy for a mass of material to end up blocking light to riverbeds and the bottom of ponds. 

 

Buildups like this can prevent healthy plant growth, cause flooding, and obstruct the path of boats. Regular dredging can help prevent toxic gases accumulating, which can become dangerous to humans and animals if suddenly released in high concentrations.

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Materials naturally flow within rivers and canals and while this helps to distribute nutrients and organic waste, excessive build-up will lead to blockages and associated issues and a proactive plan is required. From the smallest inlets through to large-scale projects, The Rothen Group works closely with our clients to maintain effective waterway functionality.

 

The complexity of the waterway will often determine the plan, such as the width and shallowness of the channel. However, through our fleet of unique modular pontoons, floating dredger boats and long-reach excavators, we are able to provide comprehensive solutions for maintaining the navigability and health of every canal and river.

 

Many of our projects are based in urban areas with slow water speeds, which requires specialised pontoons for the transportation of our equipment. In these situations, we use long-reach crane boats which are capable of spanning up to 70 feet, alongside our hopper dredgers which provide storage of any collective materials. These effective machines are often accompanied by pusher tug boats, which help to facilitate the use of excavators, diggers and drag heads. 

 

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River Maintenance

 

Safe navigation is one of the benefits of proper waterway maintenance, which includes the right type of regular dredging. 

 

Maintenance dredging is done to ensure the river depth continues to allow for the passage of boats. This tends to be routine as it is possible to estimate how much build up will occur in a certain amount of water. 

 

Sometimes it is necessary to remove sediments that have built up naturally. Capital dredging, for example, is the process of removing sediments to make a waterway deeper or wider. It happens either to rivers that have not previously been dredged or when there has been a period of at least ten years since its last dredging. This involves the safe removal of a combination of natural and man-made material.  

 

Companies like The Rothen Group (TRG) work with the Canal & River Trust and the Environment Agency. They plan ahead and make sure the necessary dredging happens before any problems arise. This is the case from the smallest inlets to the Somerset Levels.

 

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Machinery

 

Mechanical dredging cuts down the amount of time on a project. Manually removing sediment and weeds, while possible, is rarely practical and sometimes unsafe. Using the proper machinery makes more projects feasible, like our long reach excavator, which lets us remove vegetation from rivers and helps prevent floods. 

 

The equipment needed for dredging a pond, river or canal varies depending on the particular body of water and the location. In cities, where dredging often happens due to slow current speeds, equipment may need to be transported by water via specialised pontoons.

 

Crane boats are an important resource. They are simply workboats with a crane attached. These have a range of anywhere from 40 to 70 feet, and because of this, they can be instrumental in a dredging project. Their long reach can help in awkward sites. 

 

A hopper dredger allows for the material collected to be placed in a container (hopper) for interim storage before eventually being disposed of. Hopper dredgers are smaller versions of trailing suction hopper dredgers. While the latter are used on oceans and larger bodies of water, the former is more at home on inland waterways. A pusher tug boat is often used with a hopper. These workboats are very versatile, and make using excavators, diggers, drag heads, and other machinery much more efficient. 

 

River dredging, as opposed to canal specific dredging, is usually to remove non-natural materials from river beds. A combination of dredging pumps and suction pipes can be used, or excavators transported via road or boat, depending on access to the site.

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What is an example of dredging in the UK?

 

An excellent example of an important dredging project in the UK is the ongoing maintenance of the River Thames. The Port of London Authority is the body that is responsible for the safety and management of this important river, and regular dredging operations are completed to ensure the river can be safely navigated. The dredging involves the removal of debris and sediment throughout the capital and beyond, which ensures safe shipping for commercial vessels whilst reducing flood risks in this key city.

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Why can dredging be bad?

 

While the above benefits are excellent reasons to utilise regular dredging services, there are some negative impacts if the projects are not completed by experienced professionals. Without careful surveying and planning, improper dredging can harm the balance within the ecosystem by disrupting habitats and disturbing sediment which could contain harmful pollutants. 

 

 

How much does dredging cost? – Get a competitive quote from The Rothen Group!

 

The cost of dredging can vary depending on several factors, such as the size of the area, the complexity of the waterway, the amount of material to be removed and the chosen dredging method. We have our own specialist fleet, including modular pontoons, floating dredgers, and long-reach excavators, which allows us to tackle projects of every size and complexity in a cost-effective way.

 

Our team are committed to providing the most competitive quotes possible and we will accurately assess your needs to provide a detailed, bespoke quote that reflects the scope of work, time involved, and equipment required. As a leading provider of dredging services in the UK, The Rothen Group is committed to maintaining the safety and sustainability of waterways across the country, which is why we provide free, no-obligation quotes.

 

Through our expertise, bespoke machinery, and environmentally friendly practices, we aim to deliver exceptional results for every project. To find out more or to arrange a quote, please contact our team today and together we can plan a project which maintains the long-term health of our waterways.

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Your river dredging specialists - The Rothen Group

 

Benefits of this type of maintenance are numerous, and the problems involved in neglecting this aspect of waterways can be very serious and costly. The Rothen Group should be your first stop if you have responsibility for a canal, river, or any body of water.

 

With all marine construction or maintenance, The Rothen Group can help from initial consultations, all the way up until the project is safely completed. 

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