This is the lower end of the Burstwick drain beside the BP refinery.
The problems may be the outfall which seems to have been built to stop the tide - not to allow flood water to escape. The tidal barrage is 10m wide, the bridge is 23m wide to the top of bank.
The drain itself looks reasonably clear but maintenance is needed to widen the channels.
In 2003 there was plenty of weed in the drain beside Burstwick Golf Club.