199 



drought being induced in most of our main rivei-s by the destruction of the 

 bush. 



There is more liability to sixch a contingency occurring in the smaller 

 streams, and perhaps in the East Coast rivers, and in some of the Wairarapa 

 rivers, where the country is more scantily furnished with forest. 



I recollect in the dry summer of 18G3-4, observing both the Whareama 

 and the Taueru rivers to have nearly ceased running, consisting of a chain of 

 pools connected by a very small run of water between them. 



Also the Aohanga river, at a place well inland whei*e it falls perpen- 

 dicularly over a ledge of overhanging rock for a height of about sixty feet, 

 seemed at that time a mere thread of water, which the gusts of wind at times 

 dissipated into spray before it reached the river bed below. 



On such rivers the preservation of the bush about their upper courses, and 

 on their feeders, becomes an object of importance. 



It will thus be seen, from the table of areas, that the Manawatu and 

 the Ruamahanga are the most extensive and important river systems in the 

 part of the province under consideration, yet the areas drained by them differ 

 much in charactei-, and the rainfall over them is affected by different 

 meteorological influences. 



The Ruamahanga, or Wairarapa area, has much more open country in it 

 than the other, and its supply is derived from the rain falling to the eastward, 

 only, of the main dividing range of the Tararua. 



It gets most of its water directly from the eastern side of this range, by 

 the head of the Ruamahanga itself, by the Waipoua, the Waingawa, the 

 Waiohine, and the Tauherenikau, which latter falls into the lake. 



It also gets the drainage from the eastern side of the Rimutaka range, by 

 many streams chiefly discharging into the lake. 



By the Tauheru and its tributaries it drains a large extent of elevated hilly 

 land, more or less open, lying to the N.E. of the Wairarapa valley. 



By the Huangarua, the Dry river, the Rahohuru, the Turanganui, and 

 many small streams, it drains the more open country lying on the west side of 

 the watershed between the lower part of the Wairarapa valley and the East 

 Coast. The melting of the snow in summer affects it by the rivers running from 

 the Tararua mountains, and this probably to a greater extent than occurs in 

 the Manawatu area. 



One noticeable feature in the Ruamahanga is, that it discharges itself, in 

 the first place, into the Wairarapa lake, and flows out of it again not far from 

 where it enters, with the addition of the waters collected in the lake by streams 

 falling into it directly. The river, after a course of a few miles, flows into the 

 lower or smaller lake, which is divided from Palliser Bay by a narrow belt of 

 beach, through which the river flows into the sea by a channel which sometimes 

 is closed entirely by the action of the heavy surf in Palliser Bay, and then the 

 water being dammed back fills the lakes, and floods a large area of low marshy 

 land about their margins, until the accumulated water again forces a passage into 

 the sea, when the lakes subside and relieve the adjoining low levels of the 

 surplus water. 



The nature of the passage into the sea of this river has withheld from the 

 Wairarapa the advantages of a navigable river, notwithstanding the large area 

 drained, and the numerous and large tributaries of the Ruamahanga. 



The state of this area has been much modified by its long occupation by 

 European settlers ; and the substitution of grasses for the growth of bush, fern, 

 and scrub, to a large extent, must affect the rapidity with which the rainfall 

 finds its way to the streams and rivers. 



The area drained by the Manawatu system of rivers, on the other hand, 

 is still nearly in a state of nature, except what change the native occupants 



