Northleach has some flood risk, and most of it is unlikely to come from the river. Only a sliver of the town sits in the river flood zones. About one postcode in nine rates high on at least one flood measure once rainwater is counted. Nothing is on record as having flooded. The risk is real for a small number of homes, and they can be identified.
On the Environment Agency's river-and-sea flood zones, about 3% of Northleach postcodes fall in Zone 3, the highest-probability band, and another 3% in Zone 2, the medium-probability fringe just beyond it. The two bands don't overlap, so the zoned area is small, and it follows the valley of the River Leach, the only river the town has.
Surface water is a separate risk. It comes from rain that runs off fields and roads faster than drains and soil can take it, and it can reach homes nowhere near a river. The river zones leave it out entirely. In a town on a valley floor below open Cotswold slopes, it belongs on the list next to the river.
The Environment Agency also models how the zones would grow under a changing climate, and on that allowance about 7% of the town's postcodes fall inside the flood zone. That describes how far the modelled water could reach. It doesn't say when.
For insurance, the homes that matter are the ones inside the zones or on a high surface-water rating. Those are where insurers are more likely to ask questions, load the premium or raise the excess. Most of the town should be routine to insure, and a quote on the exact address before exchange shows which group a house falls into.
Count every measure the site uses, rivers, sea and surface water together, and about 11% of Northleach postcodes rate high on at least one, 11% medium and 21% low. A postcode counts if any single measure flags it, which is why this figure runs well ahead of the river-zone shares.
Counted as homes, the Environment Agency's rivers-and-sea mapping covers 320 properties in the Northleach postcodes that carry any risk at all. Of those, 18 are rated high, 28 medium and 46 low, and 8 of the high-risk properties are homes. Postcodes with no river risk don't appear in that count. Eighteen properties is a short list, and the Environment Agency's long-term flood risk service will tell you, address by address, whether the house you're viewing is on it.
The town's flood defences make no difference to the figures. About 3% of postcodes fall in the high-risk river extent with no defences in the model, and the share is still about 3% with defences included. Either nothing in the model stands between the Leach and those postcodes, or it doesn't change the result. In neither case does "defended" mean much here.
The nearest tide gauge is at Portsmouth, where the sea rose about 2 millimetres a year on the record from 1962 to 2023. That is the rate measured at the gauge, and it matters very little to a Cotswold valley town this far from the coast. The sea is the one flood risk Northleach can ignore.
No flooding is recorded in the area's historic flood record. That is reassuring as far as it goes. A record only shows the floods somebody wrote down.
Flood risk in Northleach is middling: low for most of the town, real for a short and identifiable list of homes along the valley, and worth checking address by address.