Four Mile Beach (T 816) is an exposed 6.2 km long southwest-facing high wave and wind energy beach dominated by a wide surf zone and backed by active dunes. The beach commences in the south at the mouth of Hoyle Creek, which drains out against the southern rocky section of shore and beach T 815 (Fig. 4.163). It trends to the northwest for 5 km curving round the west into Ahrberg Bay, in the lee of a lower rocky section of shore that trends 1 km southwest of the northern end of the beach. The entire beach receives waves averaging 3 m, which break across a 300 m wide double bar surf zone. The outer bar is usually rhythmic with widely spaced rips, while the inner bar varies from transverse to rhythmic bar and beach with usually 15 beach rips spaced about every 400 m dominating the inner surf. The northern corner of the beach is slightly sheltered by the northern point with usually cleaner and slightly reduced waves. In addition to the high surf there is a 1 km long section of reefs off the centre of the beach, and seven creeks draining the hinterland and dunes to cross the beach including Hoyle, George Town Packet, Newdegate and Surprise creeks. The result is a very unstable foredune and backbeach with active dunes transgressing up to 1 km inland and older vegetated dunes up to 2 km inland rising to 40 m. The active dunes are extensively deflated down to the water table with numerous small lakes and wet areas linked to the beach drainage system, as well as feeding groundwater seepage across the beach. Only the northern south-facing section of beach has a well developed and vegetated 20-30 m high foredune. The southern Top Farm, central Wilson Road and a northern 4WD track reach the dunes and beach area, with the northern track continuing out to and around the northern headland. In summary this is an exposed high energy rip-dominated beach backed by some of the most active dunes on the west coast. read more

Beach Length: 6.2km