On the 13th December WFFAA held our second Multi-Agency Meeting. All four relevant authorities joined us for this one, including Southern Water. At that meeting it was agreed that WFFAA would organise a visit to the concrete bunker on the Felpham Greensward, involving: WFFAA; Southern Water (who own the bunker); Arun District Council; and, West Sussex County Council. This meeting took place on 21st December 2012 and resulted in a constructive discussion about the internal workings of this two chambered bunker.
The evidence that WFFAA had gathered, and presented at our meetings, had always led us to believe that the key to preventing further flooding lay within the workings of this bunker. This bunker is not a pumping station as many people believe – water discharges from this pipe solely under gravitational flow. The purpose of the bunker is simply to house different types of non-return valves which prevent the backflow of sea water up the pipe.
We are delighted to confirm that Southern Water has now advised us that they will shortly commence alterations to these internal workings. These will include the removal of a redundant Penstock Valve and a Tide-Flex Valve. This should increase the flow of surface water out to sea and WFFAA’s calculations suggest that the flow rate will more than double. An additional flap valve will also be fitted to prevent the sea flowing back up the pipe (a ‘belt and braces’ defence against the tide).
Southern Water has also confirmed that they have installed a ‘Hawkeye’ level monitoring sensor in the bunker. If the level of water within the bunker reaches a pre-determined level an alarm will be triggered and an emergency response will be activated, resulting in the deployment of pumps by Southern Water’s contractors. These pumps will be connected to the two 6” (150mm) outlet valves that can be seen on the side of the concrete bunker and will result in the pumping of water over the promenade and directly into the sea. These pumps will permit the discharge of water during periods of tide locking (i.e. when the tide is in and the end of the outfall pipe is submerged), and potentially if we experience again the likes of the heavy rain of 11th June 2012.
Hawkeye level monitoring sensor installed in bunker and working.