South Ockendon is out of reach of the rivers and the sea, so its flood risk comes from rain. None of the town is in a river or sea flood zone. Around one postcode in eleven is still at high risk on some measure. Another one in five is at medium risk. The water here comes down from the sky when the rain is heavier than the drains can take.
On the Environment Agency's mapping of the river and sea flood zones, none of South Ockendon's postcodes fall in Flood Zone 3, the highest-probability band, and none fall in Flood Zone 2, the medium-probability band that surrounds it. The two zones don't overlap, and both are empty here. The Thames is close by, but no part of this town is mapped as being at risk from it or from the sea.
That leaves surface water. Because none of the town is in a river or sea flood zone, the postcodes that do show risk get it from the other things the wider measures count, mainly surface water. That means rain falling faster than the ground and the drains can carry it away. Surface water can collect on one stretch of a road and leave the next stretch dry, so the risk varies from house to house.
The Environment Agency also models how the river and sea flood zones would look with a climate-change allowance, and even on that basis 0% of South Ockendon's postcodes fall inside them. The extra rainfall that climate change brings would show up in the surface-water figures instead. Those don't include a climate adjustment.
For insurance, the lack of river and sea risk counts for a lot, because those are the risks insurers price most heavily. Homes on a surface-water hotspot can still get higher quotes or questions about past claims. Because surface water is the town's main flood risk, look up the exact postcode on the Environment Agency's long-term flood risk service and read the surface-water result, not just the river and sea one.
When all the measures are counted together, surface water included, about 9% of the town's postcodes are at high risk on at least one of them. Another 20% are at medium risk and 51% at low risk on at least one. A postcode lands in the high group even if only one of those measures puts it there.
The Environment Agency's modelled flood extents put 0% of the town's postcodes in a high-risk area with defences and 0% in one without. In other words, the defence question doesn't come up here, because the modelled river and sea floods don't reach the town. Where a defence does appear in the model, that only means a defence exists, not that the house behind it will stay dry. In South Ockendon there's nothing between the town and the river for the model to count.
The nearest tide gauge with a long record is at Dover, which measured sea level rising by about 2.2 millimetres a year between 1961 and 2010. That's a rate recorded at a gauge a long way down the coast, over a period that ended some years ago. For a town with no coastline and no part of it in the sea flood zone, it's background only.
The Environment Agency's records show no historic flooding in the area, with 0% of postcodes inside a recorded flood outline. That's a good sign, but it only covers floods someone recorded and mapped. A brief surface-water flood that cleared by morning may never have made it into the record.
Overall, South Ockendon's flood risk is middling. Rivers and the sea are no threat here, and roughly one postcode in eleven is at high surface-water risk.