Hayle's coastal and estuarine location means that it is potentially vulnerable to flooding from fluvial, tidal and surface water flooding.
Areas that have often flooded include Foundry Square and Commercial Road, Angarrack and Loggan.
- An 1875 report mentions several houses partially submerged in Angarrack and Loggan.
- In 1970 there was flooding in the Commercial Road area from the Angarrack Stream. Also in 1971 the War Memorial flooded, presumably from surface water runoff.
- In 1974 Foundry Square, Loggan’s Cross, Marsh Lane, Penmare Hotel and Golden Sands Caravan Park flooded. This was from the Angarrack Stream and Loggan’s Mill Leat.
- In 1978 Penmare Hotel flooded, from assumed fluvial sources. In 1979 Foundry Square and Loggan’s Cross area flooded from the Angarrack Stream and Loggan’s Mill Leat.
- In 1981 Foundry Square and adjacent residential areas were flooded due to a combined fluvial and tidal event.
- In 1983 Marsh Lane flooded due to unauthorised operation of a sluice. In 1985 Foundry Square flooded when water rose through the culverts. In 1988 Marsh Lane flooded due to surface water drains being locked by high river levels.
- In 2004 the Cornish Arms, Wheal Alfred Road and Commercial Road flooded due to surface water runoff. In 2006 there was small scale flooding due to spring tides. In 2008 there was flooding on the road and car park following high spring tides, strong winds and storm surge.
- In 2011 intense rainfall over one hour caused fluvial and surface water flooding. The pumping station became overwhelmed, and water flowed down Marsh Lane.
- 2016 saw flooding of the road at Foundry Hill between Foundry Square and the Mill Pond. At the same time a stream at Marsh Lane came out of bank leading to flooding of Philgray Close. Further flooding was reported along Commercial Road, Strawberry Lane, Marsh Lane and Guilford Rd.
- In December 2019 more than 50 properties flooded in and around Hayle and the A30 was closed due to flash flooding.
