The Welsh Harp or Brent reservoir is owned by the Canal and River Trust. As the Environment Agency does not own the asset, it is not responsible for dredging the reservoir or testing the chemical composition of the silt. Riparian landowners are responsible for maintaining the river channel, banks, and associated vegetation in order to control flood risk. This includes the removal of general rubbish.

The Environment Agency is, in partnership with the council, responsible for maintaining two trash screens that lie at the entrance to the Brent Reservoir: the Priestley Way trash screen that sits on the River Brent and the Edgeware auto-trash screen that sits on the River Silkstream. Both of these trash screens are cleared of debris on a weekly basis due to the large amount of debris that comes down the two rivers and collects at these locations.

The Priestley Way trash screen is due some repair and maintenance work. This will include removal of overgrown vegetation, replacement of worn/damaged parts, and removal of current debris. Whilst these repairs need to be completed to keep the asset in good working condition, they do not currently prevent the asset from operating as it should. The Environment Agency hopes to complete this work by the end of February.

Dredging is an important part of the Environment Agency’s (EA) river maintenance regime. The EA will undertake dredging where there is evidence that it will reduce flood risk to local properties cost effectively without increasing flooding downstream.

The River Weaver is a water course modified to act as a navigation and as such the water level is controlled via structures and assets that are owned and operated by the Canal & River Trust. The navigation sections are dredged to maintain standards to allow the draught of vessels.

The EA investigated the potential merits of dredging in 2013 as part of its assessment of options for reducing the risk of flooding in Northwich. The EA looked at different siltation scenarios, including if silt levels and shoals built up, to see what impact there would be on flood risk. The EA concluded that this was not a significant issue in relation to controlling water levels in Northwich, and dredging was not found to be beneficial.

The EA has allocated resource to the future maintenance of the assets – the defence walls and demountable assets – that protect the town from main river flooding. However it has not allocated funding to dredging the River Weaver.

Dredging is an important part of the Environment Agency’s (EA) river maintenance regime. The EA will undertake dredging where there is evidence that it will reduce flood risk to local properties cost effectively without increasing flooding downstream.

The River Weaver is a water course modified to act as a navigation and as such the water level is controlled via structures and assets that are owned and operated by the Canal & River Trust. The navigation sections are dredged to maintain standards to allow the draught of vessels.

The EA investigated the potential merits of dredging in 2013 as part of its assessment of options for reducing the risk of flooding in Northwich. The EA looked at different siltation scenarios, including if silt levels and shoals built up, to see what impact there would be on flood risk. The EA concluded that this was not a significant issue in relation to controlling water levels in Northwich, and dredging was not found to be beneficial.

The EA has allocated resource to the future maintenance of the assets – the defence walls and demountable assets – that protect the town from main river flooding. However it has not allocated funding to dredging the River Weaver.

Dredging is an important part of the Environment Agency’s (EA) annual river maintenance programme. The Environment Agency assesses each situation individually and will dredge when it is the right solution to reduce flood risk and provides long-term value for money.

The Environment Agency carried out a comprehensive series of trials in 2010 to review and update evidence on the benefits and effectiveness of dredging as one method for keeping rivers flowing freely. The trials showed that dredging can reduce flood risk, but its effectiveness and value-for-money varies significantly depending upon the location.

In many cases, dredging isn’t the best long-term solution because rivers can quickly silt-up again and other measures such as building walls or storage upstream may be more effective. It can even increase flood risk and erosion and alter the ecosystem and wildlife. Dredging is unlikely to be effective in isolation but it can be part of a solution involving multiple interventions.

Desilting is one of a range of activities carried out by the Environment Agency (EA) in West Lancashire to protect people and property from flooding, alongside the control of aquatic vegetation, removal of blockages and the operation of key flood defence assets, including tidal outfalls and pumping stations. The works carried out by the EA are targeted where they will provide the greatest benefit to people and property.

A recurring programme of silt surveys is in place to help the EA focus on areas where the need is greatest. The EA has secured over £70,000 for desilting in West Lancashire in 2021/22, including a desilt of the Three Pools watercourse which has multiple benefits across local residential and agricultural areas.

De-silting (also referred to as dredging) and clearing channels, are important parts of the Environment Agency’s (EA) river maintenance regime. The EA will undertake these activities where there is evidence that they will reduce flood risk to local properties cost effectively without increasing flooding downstream.

Typically over each of the past three years the Environment Agency has spent between £45 million and £55 million a year on channel maintenance, of which between £5 million and £11 million is for dredging.

Channel maintenance in West Lancashire, where the majority of watercourses are man-made for drainage, includes a range of activities to maintain conveyance such as desilting, weed cutting and removing blockages. Locally over the last three years in West Lancashire the EA has carried out £175,000 worth of desilting, as part of its recurring maintenance programme.

Between 2015 and 2020 we committed around £1 billion on the maintenance of flood defence assets. This is a real terms increase in spending compared to the £812 million spent in the previous five years.

De-silting (also referred to as dredging) and clearing channels, are important parts of the Environment Agency’s (EA) river maintenance regime. The EA will undertake these activities where there is evidence that they will reduce flood risk to local properties cost effectively without increasing flooding downstream.

Typically, over each of the past 3 years the EA have spent between £5 million and £11 million on dredging across England. This equates to approximately 100-200km of river channel each year. The EA regularly reviews its river channel maintenance programme to identify where an increase in river channel maintenance, including dredging, will provide a net positive economic benefit by reducing flood risk.

The Environment Agency (EA) refers to dredging as the removal of accumulated material in a river. It is often done to maintain channel conveyance and ensure water can flow freely. Dredging also includes ‘de-silting’ which removes material like gravel or soil washed into rivers, as well as rocks and plant life.

To protect people and properties from flooding the EA prioritises activities that achieve the greatest benefit. Dredging and clearing channels are important parts of the EA’s maintenance regime when they improve the channel’s ability to carry increased river flows and manage flood risk. Over each of the past three years the EA has spent between £45 million and £55 million per year on channel maintenance, and between £5 million and £11 million of that is spent on dredging.

In 2010, the EA carried out a comprehensive series of trials to review and update the understanding of the benefits and effectiveness of dredging. It showed dredging can reduce flood risk, but its effectiveness and value-for-money varies significantly depending on location. Historic records and modelling also show that dredging in some locations can increase erosion and flood risk for communities downstream.

Since then, further studies such as the Thames bathymetry review have validated the results of the 2010 trials. In many cases, rivers naturally and quickly return to their pre-dredged state. Therefore any flood risk benefits are so short lived that the work cannot be economically justified.

The Somerset Rivers Authority and internal drainage boards (IDBs) have trialled alternative methods for dredging. These included both cutter suction and water injection dredging, and a full-scale 5 km trial using water injection dredging on the River Parrett. The trials demonstrated some potential to reduce costs of dredging in tidal rivers. The Environment Agency uses the results of such trials and studies to decide where and how dredging will be effective, on a case-by-case basis.

I refer my honourable Friend to the answer I gave to the hon. Member for Barnsley Central on 2 March 2020, Parliamentary Question UIN 23628 [https://www.parliament.uk/business/publications/written-questions-answers-statements/written-question/Commons/2020-03-02/23628/].

I refer the hon. Member to the answer I gave to the hon. Member for Bosworth on 3 March 2020, PQ UIN 20056.

I refer the hon. Member to the answer I gave to the hon. Member for Bosworth on 3 March 2020, PQ UIN 20056.

I refer the hon. Member to the answer I gave to the hon. Member for Bosworth on 3 March 2020, PQ UIN 20056.

The Government’s flood risk management work focuses on where it delivers the greatest benefit to people and property. Dredging and other work to improve the river channel’s ability to carry increased flow (conveyance) often forms an important part of the Environment Agency’s (EA’s) maintenance regime. However the effectiveness of dredging in managing flood risk varies substantially for each stretch of river, depending on local conditions, and can actually make flooding worse if flows are quickened to towns and villages downstream. The EA assesses its value on a location-by-location basis, in consultation with local communities and organisations such as Internal Drainage Boards (IDBs) where appropriate.

The merits of dredging to tackle flooding in South Yorkshire are limited. The surrounding land and bed of the lower reaches of the river Don are flat with a very low gradient, meaning water drains slowly, and they are at or below sea level, which further slows drainage. If riverbeds were dredged lower than sea level, they would simply fill with water and would not reduce flood levels.

Dredging is one of the interventions used by the Environment Agency (EA) to manage rivers. The EA prioritises those interventions which achieve the greatest benefit in terms of better protecting people and property from flooding. Dredging and clearing channels are important parts of the EA’s maintenance regime. Dredging is used where it is technically effective, good value for money, does not significantly increase flood risk for others downstream, and is environmentally acceptable. Dredging is unlikely to be effective in isolation but it can be part of a solution involving multiple interventions.

A useful reference on the effectiveness of dredging was published by CIWEM in 2014, entitled, ‘Floods and dredging, A reality check’.

Other activities the EA uses to manage rivers include clearing aquatic weed within rivers, removing blockages such as shoals of silt, clearing debris from screens and gates and removing obstructions such as trees, so that water can flow freely along the channel.

Over each of the past three years, in real terms, the EA has spent between £45 million and £55 million per year on channel maintenance compared with between £39 million and £55 million per year in each of the three years to April 2013.

Without these interventions more flooding would have occurred over the last decade, although it is difficult to quantity this benefit.

The Environment Agency (EA) prioritises those activities which achieve the greatest benefit in terms of better protecting people and property from flooding. Dredging and clearing channels are important parts of the EA’s maintenance regime, when it improves the channel’s ability to carry increased river flows and manage flood risk.

In 2010, the EA carried out a comprehensive series of trials to review and update understanding of the benefits and effectiveness of dredging as one method for maintaining channel conveyance. The trials showed that dredging can reduce flood risk, but its effectiveness and value for money varies significantly depending on the location. Since then, further studies have been carried out, validating the results of this trial, including the Thames bathymetry review, which reached a similar conclusion. In many cases, rivers naturally return to their pre-dredged state very quickly, and therefore any flood risk benefits are so short lived that the work cannot be economically justified. The implications for downstream communities also need to be considered.

The Somerset Rivers Authority and internal drainage boards have trialled alternative methods for dredging. These included small-scale trials of both cutter suction and water injection dredging, and a full-scale 5km trial using water injection dredging on the River Parrett. The trials demonstrated some potential to reduce costs of dredging in tidal rivers.

In 2014, the Chartered Institution of Water and Environmental Management produced an independent report entitled ‘Floods and dredging, A reality check’. This explored the effectiveness of dredging and is available at:

https://www.ciwem.org/assets/pdf/Policy/Reports/Floods-and-Dredging-a-reality-check.pdf

The EA uses the results of such trials and studies to decide where and how dredging will be effective, on a case-by-case basis.

Typically over each of the past three years the EA has spent between £45 million and £55 million a year on channel maintenance of which between £5 million and £11 million is for dredging. Channel maintenance includes a range of activities to maintain conveyance such as dredging, weed cutting and removing blockages.