Little Dunmow is at moderate risk of flooding, and the risk comes from rain more than from the river. None of the village is in a river or sea flood zone. About one postcode in eight still rates high on at least one flood measure. No flooding is on record. The valley is dry on one map and damp on another, and both maps are right.
The Environment Agency's mapping puts 0% of the area's postcodes in Flood Zone 3, the high-probability band for river and sea flooding, and 0% in Flood Zone 2, the medium-probability fringe beyond it. The village lies in the valley of the River Chelmer, and the zone map still leaves every postcode out. Whoever laid out the estate kept it out of the river's way.
Surface water is a different measure and a different question. Rain that falls faster than the ground and the drains can take it doesn't need a river to reach a house, and the zone map above ignores it entirely. It is folded into the postcode-level picture further down, and that is where the village's flood risk shows up.
The Environment Agency's climate-adjusted flood zone, its projection of where river and sea flooding could reach as the climate changes, also covers 0% of the area's postcodes. Whatever the next few decades bring the Chelmer, the modelling doesn't put it on these streets.
For insurance, an address outside the river and sea zones gets the easier conversation, and on that measure all of the village is outside them. Insurers increasingly price surface water too, so a quote can reflect the postcode-level flag described below even when the zone map is clear. It's worth getting a quote on the exact address early, while the conveyancing is still cheap to walk away from, because the insurer sees each postcode separately and not the village as a whole.
Counting any of several measures, including surface water alongside rivers and the sea, about 13% of the area's postcodes rate high on at least one of them, another 13% medium and about 43% low. A postcode flagged high on that wider measure may owe it entirely to surface water. A buyer who stops at the zone map has read half of the Environment Agency's work and the more comfortable half.
The Environment Agency's modelled flood extents put 0% of postcodes in the high-risk area with a defence present and 0% without one. With nothing in the high-risk extent, there are no flood defences to weigh up here. That only settles the river question. A drain that backs up in a cloudburst has no defence modelled against it either way.
No flooding is recorded in the area. That is reassuring, and it is also a record of what got written down, about an estate that has only stood for a couple of decades and a river that has run through the valley since the Bronze Age farmers at Tooley's Farm.
The flood risk is middling. The river looks well kept out on every map, and what flood risk exists is surface water, spread across about a quarter of postcodes in the high and medium bands.