The Hurunui.

The Hurunui is the last river to be mentioned which has its sources on the eastern side of the Southern Alps, reaching the central divide. Its main sources descend from the ranges on both sides of the page 217Hurunui Pass, but are not of glacier origin. For the first eight miles of its course it has rather a narrow bed, although the valley is already of considerable width; it then expands and assumes the usual charac ter of our broad shingle rivers, till 18 miles from the Pass it enters Lake Sumner. This small lake, with a length of seven miles and an average breadth of one mile, is bounded on its northern and southern sides by fine ranges, covered to a considerable height with beech forest. It owes its origin to the existence of large morainic accumu lations at its eastern end, by which the waters brought by the river, after the retreat of the glacier, have been retained. North of it, and separated by a large isolated range, lie several other lakes, at various altitudes, of which Lake Taylor, the outlet of which joins the Hurunui three miles east of Lake Sumner, is the largest. Lake Katharine, nearly at the same level as Lake Sumner, without doubt formerly an arm of it, was cut off by the advancing delta of the Upper Hurunui. It communicates with the main lake through a huge swamp by a meandering creek, which, according to the height of the one or the other lake, is said to flow in a different direction.

For about seven miles after the' Hurunui leaves the lake, its valley is of considerable width, morainic and alluvial deposits forming terraces on both sides. At the end of this distance, the most important tributary, the Southern Hurunui, joins it. The sources of this large stream are close to those of the North Hurunui in the central chain. After first flowing through a narrow valley, the Southern Hurunui enters, in its middle course, a small plain, once the bed of a lake, and in which roches moutonnees and morainic accumulations prove the presence of a large glacier in former times; after emerging from this plain, the confluent stream again flows through a narrow valley before uniting with the Hurunui. For the next ten miles, this river occupies a deep rocky gorge through the ranges, receiving numerous smaller tributaries from both sides. It then enters the Hurunui plains, where its channel widens considerably, bordered on both sides by high terraced alluvial banks which gradually sink, so that at the eastern termination of the plains, where the Waitohi joins on its southern banks, they are only a few feet above the river bed. For the next 30 miles, measuring along the principal bends of the river, its bed is mostly narrowed, rocky mountains of middle height forming its banks on both sides. Here also, before it enters the sea, the Hurunui receives numerous affluents on both sides, of which the Waikari is the principal one in Canterbury.