The valley at Redbridge is naturally narrow. This, coupled with obstruction to water flow and loss of floodplain due to man-made structures, including old landfill, and severe pinchpoints on watercourses, leads to water being held back in the floodplain. This can affect all settlements in the west Oxford floodplain upstream, including Oxford itself.
In late 2006/early 2007, a serious pinchpoint on Hinksey Stream, at Towle’s Mill, Redbridge, was removed by the Environment Agency. In the summer of 2008 they cleared the watercourses of vegetation and carried out desilting at Redbridge. There remained however three principal pinchpoints (map) restricting water at Redbridge at the southern end of the western floodplain. OFA highlighted these to the Environment Agency and Network Rail and have worked with them to come up with solutions.
Our campaigning, and the work of our partners, has brought results:
Point 1 on the map is a large (60 ft) culvert, known as Munday’s underbridge, under the railway, and the channel known as Hinksey Drain leading to it. There is obstruction to flow here from: channel restriction due to poor maintenance and plant growth; a wall built across the channel; a 90 cm road drain pipe jutting into the channel; soil and plant growth filling in half the culvert; severe silting under the culvert; narrowing of the channel beyond, before it connects to Hinksey Stream, due to lack of maintenance.
The Environment Agency carried out improvement works here in April 2009.
Further extensive work, sorting out the remaining* problems, was done in 2013 as a multi-partner project. *Though, as at December 2014, making a properly profiled channel under the bridge has still not been achieved.
Point 3 is a roadway that allows access to the railway track and sidings where gravel is stored in bulk. The road is raised above the floodplain but the culverts provided beneath the road are totally inadequate for the volume of water present during flood conditions, so it acts as a dam.
Large flood culverts were installed by the EA in November 2009.