Broads Authority reveals key dredging priority areas

But Catfield Dyke has been named as the Broads Authority's joint top priority for dredging, as the narrow waterway fills up with silt.

The organisation has published its list of locations where sediment needs to be removed in order to keep them navigable and prevent vessels from running aground.

Dredging Hickling Broad (Image: Newsquest)

Catfield Dyke, off Hickling Broad, is the joint top priority, along with Salhouse Broad, just off the river Bure.

The Broads Authority uses various metrics to establish which areas need the most dredging.

One is the amount of use by boaters, with officials using mobile phone data from members of the public for the first time to identify busy areas.

Other factors include the depth of the channel, the amount of sediment and how much can be easily removed.

Apart from a few exceptions like Salhouse and stretches of the Bure, the top ten list of priority sites is mostly made up of spots like Catfield, which are more remote from the main waterways and less frequently visited by boaters.

Most locations are dykes and broads off the main rivers. In these areas, the natural currents are weaker and less able to help to keep the channels clear.

Also on the list are: Geldeston Dyke, off the Waveney; Rockland Broad, Bargate - or Surlingham - Broad and Thorpe River Green, all off the Yare; the Haddiscoe Cut, which connects the Waveney and Yare; Somerton Boat Dyke, at the end of the Thurne; and the stretches from Horstead to Coltishall Common and Hoveton to Salhouse, both on the Bure.

An aerial view of Catfield Dyke, which is about 1km long, coming off from Hickling Broad (Image: Google)

QUIET CATFIELD

Catfield is a very quiet location, with few boaters navigating the narrow dyke. But its sediment levels are extremely high, pushing it to the top of the priority list.

It is located on the western edge of Hickling Broad - itself notoriously shallow for boaters - and runs for just under a mile to a staithe, which has private moorings as well as free 24-hour ones run by the Broads Authority.

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A sail boat and river cruiser on the River Thurne - one of the rivers needing a large amount of sediment removed (Image: Newsquest)

Overall, the authority identifies the Thurne basin - which includes Catfield Dyke and Hickling Broad -  as its highest priority for dredging, due to having the highest amount of sediment - 307,975m³.

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The river is one of the shortest on the waterways, with large areas of open water, including Hickling Broad, Heigham Sound, Horsey Mere and Martham Broad.

The area also suffered some of the worst flooding last winter, with villages including Hickling and Potter Heigham experiencing severe problems.

FLOOD LINK

The link between dredging and flooding has been a controversial one.

Many people have urged the Broads Authority to do more to keep the waterways maintained, fearing there has been less dredging carried out in recent years.

They suspect a build-up of sediment is causing the flow of water out to sea to slow, contributing to flooding issues further upstream.

However, the BA only has the responsibility to dredge deep enough to ensure boats can navigate the Broads.

The Environment Agency is responsible for any deeper excavations to fulfil its duty to protect homes and properties from flooding.

QUESTIONS RAISED

At a recent navigation committee meeting, Daniel Thwaites, of Barnes Binkcraft, highlighted that the amount the BA has spent on dredging last year was half the amount spent in 2016.

"Why are we spending less?" he asked officers.

John Packman, chief executive of the Broads Authority (Image: Newsquest)

John Packman, chief executive, said: "We have done so much in the last 20 years that we do not need to do as much."

He added that maintenance costs have risen significantly in recent years due to inflation and increasing demand for weed cutting and removal of plant material to help keep the waterways clear for boaters.

"The spending is less on dredging but we are spending more on other maintenance," he added. 

An investigation has been conducted into river depths of the lower Bure, which has been conducted by the Environment Agency.

This will assess whether deeper dredging is needed on a section of river, known as the Bure Hump.

It follows speculation that a build-up of sediment in the area, close to Great Yarmouth, has potentially exacerbated problems further upstream, leading to persistent high water levels and flooding in communities like Potter Heigham and Hickling.