The Broads Authority is celebrating a record breaking year for its dredging operations team reaching 110% of their estimated dredging target figure. Each year the Broads Authority Construction Team aims to remove around 50,000m3 of accumulated sediment from the rivers and broads in the national park.
This is because the gradual build-up of sediment which occurs reduces the navigable capacity of the waterways. Dredging to remove this sediment build up is one of the key responsibilities of the Broads Authority.
The process of dredging is a simple one but disposing of the wet sediments when they are removed from the channels has been a constant challenge for the Authority. Fortunately they have found key ‘re-uses’ for the nutrient-rich dredged materials which changes them from a waste material to a sustainable resource. The dredged sediment is now being used to repair flood bank defences, re-creating eroded or lost river bank habitats and as a soil conditioner to improve agricultural soil quality.
The Broads Authority’s ability to re-use dredged sediments has opened new locations to deposit dredged arisings, including a large area of the Lower Bure where the sediment will be allowed to naturally dry and then be used to ‘crest-raise’ the flood bank. Sediment was also pumped from Hickling Broad to a local arable field where it will be dried and used as a soil-enhancer for sugarbeet crops. The sediment has equally enhanced a sidecast project, being used to strengthen the riverbanks along the River Chet.
Thanks to these new opportunities to recycle the sediment for an alternative purpose, the Broads Authority removed 58,540m3 of material between 2017 and 2018, reaching 110% of their estimated target of 53,000m3. The bumper sediment removal in 2017and 2018 means that the Broads Authority can concentrate on restoring their deposition sites in 2019.
The Broads Authority’s Director of Operations, Rob Rogers, said of the achievement,
“The next phase of work at Hickling Broad is an exciting opportunity for the Broads Authority and its partners as the planned works build upon knowledge and skills developed over the past few years. We have been changing the plant and equipment we use to dredge and developing exciting, innovative re-use opportunities to manage dredged sediments whilst working with local landowners to find sustainable solutions. With improving hydrographic surveys and better river bed models we are targeting accumulated sediments and better using our plant and equipment as well as deposition sites to manage the rivers and Broads.”
The construction team will continue to seek sediment deposition sites which present a ‘multi-benefit’ opportunity to re-use the dredged sediment in a positive way to restore and enhance the Broads National Park. 2018 and 2019 will see the latest phase of the Hickling Vision progress with detailed designs and planning permission sought to re-create a large area of reed swamp which should result in significant ecological benefits for the national park.
The new progress made by the Broads Authority to use dredged materials to positive effect looks to improve the experience of the Broads National Park not just for boat users but also land owners, farmers and the environment.
Thursday 7 June 2018