Project 2108 The Management of Sediment Removal & Fen Creation Works at Hoveton Great Broad

Tender description

Additional assignments under contract dated 24 Mar 2016. For each piece of work NETICS was commissioned separately, consisting of the following; - Additional survey of the Broad - New alternative design and volume calculations - Feasibility study for re-using sediment in Hoveton Marshes - Evaluation of the tender proposals - Marking trajectory with GPS and placing outlining poles, hire GPS and Boat - Review of Methodology document LAWS for execution works - Review of Health and Safety Plan - Environmental monitoring of water quality including hiring sensors and deployment - Monitoring plan and report - New designs and volume calculations Eastern Area including GPS coordinates and marking - Sediment sampling of Larkbush Dyke and calculation of Larkbush volumes - Contract negotiations LAWS - Investigation of new construction methods (connection tube, filling, equipment etc) - Writing specification of filling backfill and use of equipment, contact Ten Cate - Review of work methodology LAWS second phase - New updated designs of the tube areas with volume calculations. This additional work was needed for increasing the production speed of LAWS and also the quality of the work. Work under original contract: The first phase of the lake restoration works involved the removal of approximately 65,000m3 of sediment from Hoveton Great Broad/Hudson's Bay to achieve greater depth in both lakes. The sediment removed is used to create new areas of fen within Hoveton Great Broad. Achieved by geotubes to create bunded areas, behind which more sediment can be disposed of. Fen vegetation was used to 'cap' the bunds and it is expected that fen vegetation will spread from this material our across the back-fill of sediment. To achieve this, it is important that the correct sediment height is achieved. Works will take place over two winter periods; Oct 16 - Mar 17 and Oct 17 - Mar 18