The tide is turning at Alkborough Flats
Reducing flood risks and creating wildlife habitats
The Humber estuary is located on the east coast of the United Kingdom and comprises extensive wetland and coastal habitats. The Humber is formed by the confluence of Yorkshire's River Ouse with the River Trent from the Midlands. The Humber forms the most obvious dividing line between the North of England and the Midlands. The estuary drains a catchment area of some 24,000 km2 and provides the largest single input of freshwater from Britain into the North Sea. It has the second-highest tidal range in Britain (7.2 m) and as such, the coast of the Humber is macro-tidal. Approximately one-third of the estuary is exposed as mud- or sand-flats at low tide. The tidal range in the Humber estuary varies from 3 m during neap tide to 6 m during spring tide. The high water level at Goole on a spring tide is more than 1 m above the level at Spurn. During extreme events, water levels can be up to 3 m above normal levels.
Philip Winn, Environment Agency
The principal objectives of the project were to provide flood storage on Alkborough Flats so as to facilitate flood defence benefits and to create a new inter-tidal habitat that contributes to ensuring the area's integrity, such as the Special Protection Area (SPA) and the possible Special Area of Conservation (pSAC), are main-tained in the long-term, in light of predicted habitat losses arising from sea level rise and to compensate for losses arising from tidal defence works elsewhere in the estuary.
David Wheeler, Scheme Adviser
CARNYX WILD were asked to supply long term monitoring equipment for a visual measuremnt of tidal phases and extremes. It was decided that a simple and portable approach would deliver the best results. We suggested a self contained timelapse camera that could be setup infront of a water depth gauge. This type of kit will run for many months unattended and can easily be moved to alternative sites over the study period. The equipment also allows for the downloading/retrieval of images at any time over the Mobile 4G Network. The resulting date and time stamped video was then matched up with weather and tidal information. This formed an important part of the assessment of the flood storage and inter-tidal habitats.
The Final Result:
1. An effective inter-tidal habitat created as part of the UK's Flood Risk and Management in Estuaries project, which relieves the pressure down stream.
2. The provision of an enhanced wetland wildlife habitat as part of the UK Biodiversity Action Plan.
3. The enhancement to the public amenity value of the area.
Peter Dobson, Carnyx Wild