The coastline at Winterton has historically been well known as one of the most hazardous parts of the British coastline due to shifting sand banks. On visiting Winterton-on-Sea in 1722 Daniel Defoe remarked on all the houses of the village being made from the timbers of wrecked ships. The hazardous nature of the coastline at Winterton-on-Sea is marked by its lighthouse whose history extends from James I to the First World War
In the late eighteenth century marram grass was planted to stabilise the coastline against sea encroachments and by the early nineteenth century there was a barrier of dunes between high water mark and the ridge on which the lighthouse stood, leaving a valley (The Valley) between. ["Lights of East Anglia", Neville Long, 1983]
During World War II, anti-invasion defences were constructed around Winterton-on-Sea. They included a number of pillboxes. The beaches were protected with unusually extensive barriers of scaffolding and large numbers of anti-tank cubes.
Over the second half of the 20th century the coastline at Winterton-on-Sea has changed significantly, resulting in some loss of the dunes. The village (like other parts of the Borough) has a flood siren installed which can be used to warn inhabitants. Erosion and flooding are potential risks to the village of Winterton-on-Sea and the Winterton Dunes; as the area is mostly situated at approximately sea level. Although it should be noted that the recent local flooding has occurred in urban areas such as Great Yarmouth were due to inefficient drainage rather than coastal erosion and the Environment Agency's model for flooding indicates that most of the village property would not be affected. However much of the land in Winterton to the North of the village which is part of Burnley Hall Estate; and the nature reserves in the Winterton Dunes, which are home to some species not found elsewhere and a unique habitat not found elsewhere in the country are at risk. The loss of either of these would result in a serious and possibly irreparable loss of wildlife Duffles Pond, a Seal Sanctuary and the local allotments are also at risk.
On the 12th of January 2007 the Environment Agency issued a statement regarding the Flood Defence budget for 2007/8. The budget; planned and distributed on a national basis apportioned £33,000,000 to the Eastern Area. The Anglian (Eastern) Regional Flood Defence Committee expressed their disappointment at this; being £5,200,000 less than the 2006/7 budget due to other areas nationwide taking priority. The Committee were particularly disappointed to hear that funding had not been allocated to realise proposed schemes for development of flood defences from Eccles to Winterton. Proposed schemes for Ipswich and Jaywick also did not receive funding for 2007.