The Auckland Star: WITH WHICH ARE INCORPORATED The Evening Morning News and The Echo. MONDAY, MARCH 31, 1913. FLOODS AND FORESTS.

Auckland Star, Volume XLIV, Issue 76, 31 March 1913, Page 4

The Auckland Star: WITH WHICH ARE INCORPORATED The Evening Morning News and The Echo.

MONDAY, MARCH 31, 1913. FLOODS AND FORESTS.

For the cause that lacks assistance, For the wrong that needs resistanat, For the future in the distances And the good that we can do.

The destructive floods which have just been experienced in Southland should have the effect of calling public attention once more t<j the source and origin

of these constantly recurring disasters, and suggesting the means by which they can be prevented or averted. In Southland, as in so many other parts of 2vew Zealand, a large proportion of the native -bush has been cleared from the ■banks of the streams on their upper readies, and. the natural consequence is that whenever heavy rains come the low-lying ground near the mouths of the rivers is always liaible to destructive flood-. The record of Hawke"s Bay, of the Marlborough, of the VVanganui district; in fact, of every part of the country where bush-clad hills have been cleared has beeu the same, and we need hardly add that in this respect X<mv Zealand is only corroborating the experience of older countries like France, and Italy, and Switzerland, and of comparatively young countries like, the United .States, -where deforestation has ahravs bronght floods in its train. The jreat inundation* that have ju.-L devastated the Ohio Valley, inflicting enormous

pecuniary damage, accompanied by deplorable loss of life, arc for the most part directly due to the cutting down of Lhp forests; and it is high time that the people of this country camp to realise the disastrous consequences of deforestation, and set about applying the only effective remedy. It is not difficult to appreciate the. necessary connection between deforestation, and lloodtt when once the facts are clearly stated. Trees ami the undergrowth thai, surrounds them play an extremely important part in our natural drainage system. "The water from heavy rains," says an eminent German authority, "checked in it* descent by meeting first with the foliage of trees, is better retained on forest, soil than on 'hare land. Under a close cover of trees there collects a 'humus' soil formed from the decay of fallen leaves. Through this sponge-like covering the rain water slowly filters, and its passage is further retarded by -th« ste.ms,., ,ao4root- of the trees. In this way the erosive effects of violent rain-s upon liare hillsides is obviated." But when the bush is cut away there is nothing U> check lho fall of the rain, to help it percolate through the soil, or to hold back the rush of the storm-water as it sweeps over the hardened surface of Uic ground. As Professor Trotter tellr. us: "In a region denuded of trees the heavy dash of rains washes away the loose earth, carrying it into the stream.-?, which become firrbkl torrents. In the spring, when the ground is still hard from frost, the rainfall runs off the slopes, leaving only a small part to Rink into the ground. This- immediately swells the brooks and tributaries of a river basin beyond their carrying capacity, causing freshets which tear a"way the ba , nks and obstruct the channels at various points with aeciimmulations of stones and other debris. The over-full brooks discharging into the larger tributaries raise 'the waters of the rivers into mighty torrents that sweep sea-ward, often causing disastrous floods in the valleys." Thin i<. in brief. the history of nearly nil river basins where timber lias been cut down wholesale. It has already 'born admitted by the leading engineering authorities otUwhed to our Public Works Department that t-he some series of events lias been

set in motion here; and the time has now surely ennie to pra-pple -with this prreat problem in a .practical way, and

iiot only to prevent further damage to t-he conn try frrtni this cause, but, as fAr as may be. to repair tlie injnry already done iby the reckless destruction of our native

It would takr far more space than wo have at our disposal to describe the consequences of Deforestation in regard to floods in Central and Southern Europe and in North America. For over a century the French Government has been spending money lavishly to combat the evils of Deforestation in L.anguedoe and Auvergne; while in Italy and Switzerland, where the same causes have produced like results, it is now generally recognised that the only effective remedy against the floods which periodically devastate the valleys and plains is the conservation of the forests, or, where that remedy comes too late, the systematic replanting of trees on scientific lines. In New Zealand, as in America and so ranmy otbor eonntriea, great damage has already been done; though, happily, it is not yet irretrievable. Incalculable injury has already been inflicted on the country, and heavy losses have been suffered by its settlers, not only through Hie direct damage due to floods, but through the other destructive consequences of Deforestation. The denudation of the hillsides is followed everywhere by the erosion of the Boil; the fertile earth ie washed from the uplands, and tihe val-leys-at the foot of the hille sre overlaid with gravel *nd clay (brought down by the disintegrating pow-er of wind acd weahher when once the sheltering bush is out away. The streams aTe flooded, productive "fields are overlaid -with bar-

ren debris, watercourses age choked tili the current changes ite course and carriee more coil away, harbours are silted up, and untold "wealtih must be epent in protecting the river banks, deepening the river -beds and making our ports and waterways navigable. Much more might be -written on this subject, but we have probtubly said enough for the time to emphasise the ruinous injuries inflicted by Deforestation on this country. Yet the remedy lice ready to hand. For a systematic policy of replantation and affrrreetation -would not only save us from a continuance of these lofee«, ant l

provide ue -with a practically inejth.iust'.ble supply of timber, but would put an end to the recurrence of such destructive floodis ais tibat which the farmers and settlers on the plaine of Southland h:ive now such good r-eaeon to depkrre.