Does Longrock flood?

What the Environment Agency's rivers-and-sea flood-risk data says about Longrock

Ordnance Survey places 28 postcodes in Longrock in the Environment Agency's rivers-and-sea flood-risk dataset (Risk of Flooding from Rivers and Sea). Each postcode is counted once, under the worst band any of its properties reaches; together they hold 282 properties in the EA dataset's likelihood bands.

This dataset covers flooding from rivers and the sea only — one of five flood sources. Surface water, groundwater, sewers and reservoirs are assessed separately, so a postcode missing from it is not proof that a place cannot flood. The band describes the land around properties (allowing for defences), not any single address and not today's conditions.

Rivers and live river levels near Longrock

Environment Agency gauges within 10 km of Longrock watch Lariggan River, Newlyn Coombe River, River Hayle, River Stennack, North Cornwall Coast.

• Penzance Alverton
  Lariggan River · 3.9 km away 0.06 m
  normal range · steady · 1 h ago
• Newlyn Tidal
  Tide · 4.2 km away 2.06 mAOD
  rises and falls with the tide · 1 h ago
• Newlyn Coombe
  Newlyn Coombe River · 4.3 km away 0.11 m
  normal range · rising · 1 h ago
• St Erth
  River Hayle · 5.7 km away 0.19 m
  below normal · steady · 1 h ago
• Relubbus
  River Hayle · 6.8 km away No recent reading
  last reported 10 Sep 2026 16:45
• Hayle Tideflap Tidal
  River Hayle · 6.9 km away 2.96 mAOD
  rises and falls with the tide · 1 h ago
• St Ives Consols Farm
  River Stennack · 8.5 km away 0.02 mASD
  normal range · steady · 1 h ago
• St Ives Tidal
  North Cornwall Coast · 9.6 km away 2.90 mAOD
  rises and falls with the tide · 1 h ago

Distances are from the middle of Longrock's at-risk postcodes. Tidal and structure gauges are shown as readings only — the tide and sluice gates move them, not floods. A gauge with no recent reading shows no level.

Flood warning areas near Longrock

10 Environment Agency flood warning areas lie within 10 km of Longrock. The EA has issued 664 flood warnings and alerts for them since 2006, most recently on 2 Mar 2026.

• South Cornwall coast at Mounts Bay, properties located behind the sea front in Newlyn, Penzance, Longrock and Marazion
  6 warnings and alerts since 2006, latest Oct 2023 0.1 km
• Lands End to Lizard Point including Mousehole, Newlyn, Penzance, Longrock, Marazion, Praa Sands and Porthleven
  135 warnings and alerts since 2006, latest Feb 2026 0.2 km
• South Cornwall coast at Mounts Bay, seafront properties in Newlyn, Penzance, Longrock and Marazion
  37 warnings and alerts since 2006, latest Dec 2025 0.4 km
• Riverside properties and roads along the Newlyn Coombe River at Newlyn including The Strand, The Coombe and Tolcarne 4.4 km
• River Hayle from Relubbus to St Erth including Relubbus, St Erth and Hayle Causeway
  16 warnings and alerts since 2006, latest Jan 2026 6.5 km
• Lands End to Chapel Porth including Sennen, St Ives, Carbis Bay, Lelant, Hayle, Portreath and Porthtowan
  59 warnings and alerts since 2006, latest Dec 2025 7.0 km
• Lands End to Chapel Porth including Sennen, St Ives, Carbis Bay, Lelant, Hayle, Portreath and Porthtowan
  206 warnings and alerts since 2006, latest Feb 2026 7.0 km
• Penzance, Newlyn, Crowlas, Porthleven, St Ives, Hayle, Camborne, Portreath and Perranporth
  158 warnings and alerts since 2006, latest Mar 2026 7.5 km
• Lands End to Lizard Point including Porthleven Harbour, Mousehole, Praa Sands and Mullion Cove
  37 warnings and alerts since 2006, latest Dec 2025 8.7 km
• Low-lying areas around Copperhouse Pool including the B3301
  10 warnings and alerts since 2006, latest Sep 2024 9.5 km

Recorded floods near Longrock

Floods whose mapped extent (EA Recorded Flood Outlines) reached within ~5 km of Longrock, most recent first. Absence of a record does not mean a place has never flooded. See them on the map →

• 8 Apr 2024 — Penzance Sea
• 8 Apr 2024 — Newlyn Sea
• 23 Mar 2023 — Newlyn (site 14 - opp Heritage Centre) Sea
• 22 Mar 2023 — Marazion, St Micheal's Mount car park Sea
• 22 Mar 2023 — Penzance (site 4 - harbour) Sea
• 22 Mar 2023 — Penzance (site 6 - footpath / prom) Sea
• 22 Mar 2023 — Newlyn (site 13 - Old bridge) Sea
• 3 Nov 2022 — Marazion Main river
• 31 Jan 2021 — CW9668 - St Erth
• 16 Dec 2020 — CW9662 - Penzance Sea
• 20 Aug 2020 — CW9643 - Mounts Bay Ordinary watercourse
• 13 Feb 2020 — Marazion Main river

…and 54 earlier recorded floods on the map.

Rainfall near Longrock

The nearest rain gauge, Rainfall station (4.8 km away), recorded 0.0 mm in the last 24 hours and 27.2 mm in the last 7 days (latest reading 1 h ago).

At-risk postcodes in Longrock

Every postcode Ordnance Survey places in Longrock that appears in the EA's rivers-and-sea dataset, worst band first. Each links to its own flood-risk page.

High likelihood (16)

Medium likelihood (6)

Low likelihood (3)

Very low likelihood (3)

Postcode districts

Sources

FloodRadar summarises public flood data. It is not a flood-risk survey of any property, and it does not replace official GOV.UK flood warnings or the GOV.UK long-term flood risk service.