Awakino Sand Bar

Sand bars have developed at the mouths of each of the major rivers in North Taranaki. Here at the Awakino Heads we can see the largest of these in the local area, about 2 kilometres long. It has grown through a combination of the sand transported down the river being deposited on the river-side of the barrier, and from sediment when it enters the sea, transported north by longshore currents and waves.

Each of the major rivers in the area e.g., the Awakino, Mokau, Mohakatino and Tongaporutu rivers have a sand bar or barrier developed at their mouths where they enter the Tasman Sea. Some people might call them sandspits, but a sandspit typically grows by the buildup of sand by longshore drift moving in the direction of the tip of the sandspit. (A typical example is Farewell Spit which is building toward the east over time by sand being transported northward up the West Coast of the South Island.) What is interesting about these Taranaki bars is that they are all connected to the land at their northern end and have their tapered tip (or end) to the south. This orientation is opposite to the prevailing longshore drift direction which in North Taranaki is toward the north. The Awakino bar (and the other North Taranaki rivers), grow toward the north, from the sediment deposited by the river when it enters the sea, north away from the tapered end of the bar rather than toward it as might be expected.

In times past during exceptionally large floods, the river might be able to break through the northern part of the bar directly to the sea, but today, all the rivers have a right angle bend behind the barrier, and turn to the south before entering the sea. Part of the reason for this, is that the rocks below the river dip to the south, so the river follows this local gradient until entering the sea. The bars at the mouths of the rivers in North Taranaki are dynamic environments for sand movement. At the Mokau bar for example, coastal erosion by waves has been a major problem for decades.