Heswall Dales offers wonderful vantage points from which to view the Estuary of the River Dee and the hills of Flintshire. It is approximately 6.5km (4miles) wide here. The river has its source in Snowdonia and flows for 110kms to enter Liverpool Bay. The Estuary is internationally important for wildfowl and wading birds. It is designated a Site of Special Scientific Interest under the Ramsar Convention and is the fifth largest UK estuary featuring hundreds and thousands of birds passing through and feeding while transiting from southern Europe to Scandinavia, Greenland and other parts of the Arctic. These include birds such as Knot, Redshank, Godwits and Brent Geese.
The Estuary was not eroded by the river on its journey to the sea. Rather, it was carved out by the passage of ice moving south eastwards from the Irish Sea some 10,000years ago. Hence, the Estuary is silting up, not with material transported downstream by the river, but with sand and gravels washed inland by the sea. Such rivers are known as “misfits”. The mud and sand flats exposed at low tide are nutrient-rich for the birds.
The channel from Thurstaston, past Heswall and on up to Parkgate, shows a small (10-20cm) tidal bore, best seen from Heswall Fields.