Question 1

Does Selsey flood?

Accepted Answer

From rivers and the sea, parts of it can. 85 of Selsey's 360 postcodes have their centre point inside Environment Agency flood zone 3, the highest band, and 14 more sit in zone 2. These zones cover rivers and the sea only and ignore flood defences. Rain is a separate risk: on the Environment Agency's surface-water map (read 2 November 2026), 125 of the 360 postcodes (35%) have high or medium risk within 25 metres of their centre point. Groundwater isn't mapped in either, and a postcode is not a house: check an exact address on GOV.UK.

Question 2

Will Selsey flood more in future?

Accepted Answer

Yes, noticeably more, on the Environment Agency's climate change scenario. Its long-term flood maps, unlike the flood zones above, count flood defences. From rivers and the sea, 69 of Selsey's 360 postcodes have their centre point at high or medium risk today, and 141 under the scenario, which runs to the 2050s with sea level rise to 2065; at high risk alone, 38 today and 136 then. From heavy rain, 125 have high or medium risk within 25 metres today, and 174 under the scenario. High risk means at least a 1 in 30 chance of flooding in any year, and medium means between 1 in 100 and 1 in 30. The maps were read on 2 November 2026.

Question 3

How often does Selsey get flood warnings?

Accepted Answer

The Environment Agency issued a flood warning for part of Selsey on two days in the ten years to June 2026, most recently on 9 April 2024. 121 of its 360 postcodes sit inside three Agency flood warning areas: "Medmerry" (The Solent, English Channel), with warnings on one day; "Sidlesham" (English Channel), on one; and "Selsey East Beach" (English Channel), with none. No severe flood warning, the level that means danger to life, was issued in that time. Flood alerts, the earlier message that flooding is possible, went out on 20 days in that time, most recently on 8 January 2026. Warnings cover flooding from rivers and the sea, and groundwater in a few places, not heavy rain on its own. Each count is of days on which a new warning or alert went out, so updates on an event already running are not counted again.

Question 4

Is the coast at Selsey eroding?

Accepted Answer

Not where homes are, on current plans. The shoreline plan for the 9.4 km of coast within 500 metres of Selsey's postcodes is to hold the line, keeping the existing defences, through to 2105. None of its postcodes has its centre point in land the Environment Agency's erosion map expects to be lost by 2105, if that plan is carried out and with its higher central allowance for climate change.

Question 5

Are there old landfill sites near Selsey?

Accepted Answer

Yes. The Environment Agency's record of historic landfill sites shows four within 500 metres of a Selsey postcode, and twelve of its 360 postcodes (3%) have their centre point on one or within 250 metres of it. The one closest to most postcodes is West Street, for which the record gives no dates or waste types. The others are Sidlesham Ferry, Golf Links Lane and West Sands Caravan Park. A historic landfill is an old tip with no environmental permit in force: one that closed before tips were licensed, or whose licence has since ended. The Agency says much of its record comes from a national survey in the early 1990s, so it may be incomplete, and some boundaries are only approximate. An old tip nearby does not by itself mean a problem; the council's contaminated land register, or a search on an exact address, says more.

Selsey flooding and flood risk

Does Selsey flood?

Future flood risk in Selsey

How often does Selsey get flood warnings?

Is the coast at Selsey eroding?

Are there old landfill sites near Selsey?

Flooding and land in nearby places