River Orwell

Ipswich has in the past been affected by flooding, both fluvial flooding from water passing down the river Gipping, and tidal flooding from tidal surges passing up the estuary of the Orwell, with the river becoming much narrower near to the entrance to Ipswich Docks. In order to reduce this risk, the Environment Agency implemented a programme of works expected to cost a total of £58 million to improve the flood defences on both banks of the tidal river and of the Port of Ipswich. The work included the construction of the Ipswich tidal barrier, and because the work affected the right of navigation on the New Cut, the section of the Orwell immediately above the barrier site, it required an order to be issued under the Transport and Works Act 1992. The Ipswich Barrier Order was issued by the Secretary of State for the Environment, Food and Rural Affairs in August 2012.^[8]

The barrier consists of a rising sector gate, 66 feet (20 m) wide and 30 feet (9 m) high, located just to the west of the entrance to the wet dock. In November 2014, a contract for £28 million was awarded to VBA, a joint venture between VolkerStevin, Boskalis Westminster and Atkins, for construction of the barrier and associated flood defences on the banks of the river. The barrier is designed to prevent tidal surges passing further up stream, and to enable downstream fluvial flows to be controlled. It provides better flood protection to some 1,500 homes and 400 business properties. The river at the barrier site was 180 feet (55 m) wide, but in order to allow the construction of the barrier and the commissioning of the gate, a large cofferdam, 98 feet (30 m) square, extending 20.6 metres (68 ft) downwards into the chalk bed of the river, was formed against the east bank. This left a much narrower channel to allow the river flows to reach the estuary and boats to continue to access the river above the barrier site.^[8]

The sector gate was designed by the German firm IRS, and was manufactured in Holland by Hollandia. Once assembled, it was floated across the North Sea, and lifted into the concrete support structure by a 600 tonne crane. The position of the gate is moved by two hydraulic cylinders, and it can be positioned to prevent a tidal surge passing up stream, or to regulate the downstream flow of the river. The concrete structure was tied in to the eastern bank early in the project, but ties to the western bank had to wait until the gate had been commissioned. At that point, both the flow of the river and boats could pass through the new structure, and the side channel could be blocked off.^[8] The new barrier was officially opened in early February 2019 by Therese Coffey, Floods Minister at the Department for Environment, Food and Rural Affairs, by which time the cost of the project had risen to £67.4 million. While most of the funding came from the Environment Agency, some was also provided by Ipswich Borough Council, the New Anglia Local Enterprise Partnership, the Regional Flood and Coastal Committee, and UK Power Networks.^[9]

The 1957 film Yangtse Incident: The Story of HMS Amethyst was filmed on the river. The naval shore establishment at HMS Ganges also featured in the film being used as a site for Chinese gun batteries.^[10]

51°58′N 1°18′E / 51.967°N 1.300°E / 51.967; 1.300