WAIMATAITAI BEACH.

Timaru Herald, Volume LXXXIII, Issue 12912, 1 March 1906, Page 3

WAIMATAITAI BEACH.

AI/ii-lUKD BY THE XEW MOLE

Within the past three or four weeks tf c'-r.: i.:c:-..b!e ci-ougs lias been caused in the cvi..;:ii,>;i tf the VVaimataitai beach. A lilili tar.ier. surprise was occasioned by the ;:;[.ou.uito of shingle n:ia <-.ind along ihc fj.«u df Benveuuc chiT. extending to the sands «: Caroline Bay. and uilim.-itdy the wh:.lc of this was d;i;icd to the Kind and i:e;.pod up as a rial spit a'ong the foot of :he Dairy Factory spur. The shingle and t»aud came from the Waim.Uakai spit, and consideration of the' ciicum»la:ices at the time led to the conclusion that the material was thrown round the northern corner of the Bcnveuue cliff protective rubble mound, by a rush of water out of the lagoon, iu tne last flooding rain. It seemed to be necessary to count on the aid ofy the outflow from the lagoon, because at that time the low-water line of the beach was too far back to permit the sea alone to carry shingle round the corner; and a rtroas stream from the lagoon certaislv carried i a large quantity of shingle beyond the .normal beach line. The result of that particular action appears to be cow exhausted. Practically all the material tben started round the north corner has reached the southern end of the Benvcnnc cliff. It is quiti remarkable how narrow is the path it was driven along, as indicated now by the scouring of weeds and bhell-fixh off the rubble; and equally rcmarkiibl* is the almost perfect removal* of other traces of its passage. Even in d«p and intricate interstices among the boulders there is iu mest cases no sand or gravel left, whero the cleaning up has been completed. More recently a tendency has been developed for the whole of the Waimaiaitai beach to drift southwards, with a probability that mere or less of it will be drifted to the sands. At low tide the surf line on the Waimataitai spit is now quite outside the north end of Benvenne cliff, there being a beach of sand clear of the rubble, and 'one could wait on sand, stepping between the ton* of rubble blocks, as far as the remains of the old wreck. This change has been brought abeut by a few moderately heavy easterly and southerly seas, within "the hwt month or so. The whole length of the spit has bsen affected. Previously the spit presented an almost straight line from end to end; now there is a decided curve or angle in it, the consequence of a large addition to the southern end. of material drifted from the major portion of the length of the spit. Of late years, until now. tne southern end of the spit La* been the weakest; it was theie that the racoon when full broke out or was let out. \ow except for the gap scoured bv tho last escape of a flood, the southern 'end of the beach is the widest, and at the present moment( eave for the gap just mentioned, (winch a heavy sea muv fill up any day) tie weakest part of the beach is at the extreme north end. Apart from considerations of possible consequences of the drift of the beach along the Benvenue cliff, tie most remarkable alteration iu the aspect 01 the beach is to be eeen at the northern end. Those who have been familiar vith Jt will remember that ever since the *pit trapped there has been a space of beach two or three chains long, near the northern end,-'coveted thickly on tlie «eaward face with'dolcriie boulders, JLat the waves had dragged from the tumbled rvl ble beyond, or drifted from the south; ?td that this rubble was mixed with and backed by big Waitafci boulders. Recent action of the sea has drifted many of the*e boulders southward*, and they "lie thickly scattered along the bench slope for fully "s thiid of the length of the spit. There still remain two heaps of these boulders near the north end, one a small one, mostly composed of Waituki boulder*, near to the plantation: She other, a larger one, composed of big dolerite boulders, further sbutli than where they used to be. The earlier tendency was for the sea to drive these boulders northward, until they were stopped by the backwash from the new rock face at the north pide of the spit. A new tendency has shown itself, to drive them southwards, and looking from tie beach tothe new mole, it is evident, that this tendency must continue, for the mole will cut off th; seas that formerly caused the north ward drift. Sen* that can shift these dolerite boulders con of course easily drift "shingle, and concurrently with thesout-V ward drift of the boulders the northern end of the beach gent rally has been considerablv cut away, and the material brought along and laid down nl the south end. This alteration is well seen in the expceuie of tie two old stumps, which have been landmarks since ihs great storm of ISB2. One of them is now lying on the seaward slope, and the othev has been taoured out and capsized, jwt on the new eroU <?i denrdatioii. The change is also well seen in thj exposure of the clay beneath the shingle or. the seaward side, tie clay being now vis ible :it a number of points along tin- li;r.«h from the stumps ntuihward. In view of the shelter from «-outher3y seas afforded by the new mole, it seems probable that "the southerly drift of the Waimataitni beach, lately manifested, will continue. Northerly seas will drive the> I beach southward directly, and easterly and southerly seas by reflection from the tumbled rocks mi the north side of the new bay; and no waves can reach the beach so as to cause a return drift. Some interesting consequences ni3y be looked for. Formerly it seemed likely" that the beach Tvould be gradually shifted landward, regaining its present direction', in casethe railway line would presently require further protection, and before man? yews

bad passed a diitkuhy would ,-jjiM; m main-l-dIIJIVg jllC C!jM>C «5 jb« «>di under J&C line. Xow. with a beach dialling mmh' i ward, the railway and the creek outlet will be safe fwr a much longer ti«w.. The north end of she spn may be thrown bs<is ni«fc rapidly than ever, bar a? h~* a *w.d ; way to go to ijj c railway, and 3c«g 1 **<*»• it ivachtw the coibanJiincnl. ?3»c brarb Jiuc ; must .i»j?i,sc a direction übidh will cobM' jj tcr.icl the drifting action. What ".be effort jof tic Mratihicrly drift wjM be on She €■«**- j line Hay wnd* <sf material thai Snivel* along she *f<**t, «f Ilcnvctiuc cliff. So far a* "the >»>;i'l <ju»». I tity thai ha* cotne along j* wftocrfied. ji jhas been kept very dc*cly together, ajvd ,flwc to the star*, except a, Jew pcbb3c* which have bees Mattered *3<>riji *and jby fcse rush of (effected waves. The *.«t»c : result may be anticipated, if % larger upastily conies along. If a large and rc^lar drift is *«t up along Iktrraiue diff, a practical mischief may iwoe from the di» minutkin of the quantity of material in the spit. The solid groucd underlvwis the spit k fortunaKly a very tough" clay at the top. aad powdbly thai w wcgne »h]t>g3« beneath which wosld help to mMiAhir, t*-,e spit. At tie beginning of the )•«;«•&-srard drift of the north cad there wa* wait iui-ocb blue shingle washed up. bus tlars d<w:» v,« appear to bav,e been any of the *amc kind ! rcoJcd up lately. Thtwe who Sa-W as in- I tcrcst in the effect* of the Imbour wojk*| on Uie adjactnt coast line trill do well to \ keep an eye on tibe Waimatait-aa »fiit. |