EROSION PROBLEMS

Chronicle (Levin), 17 July 1946, Page 3

EROSION PROBLEMS

^ — ITEMS FROM CATCHMENT BOARD MEETING ! , The followiug matters of general in- ' terest were dealt with by Ihe Alanawatu , Catehment Board at its monthly meet-, i ing held in Palmerston North yesterday t wlien the eliairman (Mr. J. T. J. Jtieatley) presided over Alessrs. J. B. Car ruthers, G. L. Ewcn; W. Mclvay, T. A. «I olinston, Al. O- Grainger, C. Borbes, ,1. Jlamblyn, H. W. Barber, B. A. C. ; Barby, J. 1). Aitchisou, li. Lind, E. ' Bruee Levy, J. B. Chrystall and li. lb deiisen: — A request was received from tlie Manakau Land Syndicute tliat ihe board shouid consider the purclnise of a,n urea of 3«8J acres in the Taungata survey district, Otaki liiver catclnnont urea. The block had })reviously been oll'ered to tlie »Soil Oonservatiom and Rivers Control Couneil, and turned down. The syndicate poiuted out tliat if the board did not mako the purcliase; it would have to niiil tlie tiinber and clear tlie busli for firewood as a re-i-onipen.se for the rates and- land tav paid over a great number of years. J\Ir. S. A. C. Darby, (.'ouservator of State Lorests in Balmerston Xorth, said the urea had already been milleil for limiier. Au adjacent urea of 1.0,000 acres was shortlv to be milled. Although the board was conceruod lo ratahi cover 011 the land, it would liave to stcp warily in eonsidering laud purclmses, he thought. Mr. K. Bruee Levy: "We miglit be expected lo buy Ihe whole of tho Tararua foothills. ' The matter was refcrrcd to the board 's All'orestation Oommittee for consideration. A request for assistance was received from Mr. P. J. Cole, Lhannon, for preventing erosiou ua liis jiropertv, caused by tlie Otara Stream. A re.cent serious wiishout had gravely threatened a road bridge. ll was decided tliat an ins]iection of Ihe atea shouid be made for tlie purpose of making a recommeudalion. Raukawa Bend Problem The Oroua Oounly Couneil ugain dicw atteiitiuu to the serious troulile bcing caused at Raukawa Bend in tlie Manawata River where u setller had erected a stop bank across au accretion. It was suggested tliat the board shouid put a cut through tlie accretion. Mr. \V. Mclvay: The erosiou l liere is llirealeiiing the. roadway. The acting-engineer (Mr. L. Baly) po'tnled out tliat Ihe stopbunk was across the course of the proposed cut tliat was part of tlie board 's major com l ro] sclieme for Ihe river. lle thought it would be unwise to ma ku a preiimture cut in tlie accretion. Althougli siu-h action might relieve Ihe position at the Raukawa Beud it would cause serious trouble on Lhe other side of the cut. It was reported tliat Ihe stone groyne ereeteil |>y a setller across the overilow I'lianuel had been demolished. A'n inspection is to be made of the area, and a report brouglit dowu to tlie ne.xt meeting of the board. The district eugineer, PAV.l)., "Wellington, adi ised tlie issue of a monetary aulhority in the sum of £75 (£1 for £1; fb'f /•nation cohtrbl oii 'AIRni 's pVbperly'/ and £bs(J (£1 lor £1) for MiJne's erosiou, botli localed ou the Mangatainoka River. Mr. Baly reported tliat vork on Allen's erosiou had been completed. The river had created a sharp bend seriously threatening Ihe access road. The remedial nieasures advised were the ojiening up of the old channel and the const ruction of a siiingle stopbank to hobl the river in its old course. This work had been completed and was o[»erating sat isfactorily. After tlie completion of Allen's jo!>, it was considered expedient and ecoiiomical to carrv on w.ith tlie wor >c at .Milne's. This joli would be completed uithin the nest few days. An i nspect iou had been made of the erosiou on Mr. Cuwiu's proporty at Konini. The river had developed a hairpin bend with very active erosiou aloiig the concave bank. Levere daniage to tho railway embankment was taking place a sliort dislance above tlie- bend. A cut-oH". apjiroximalely four chaius in lengtli, through the railwav reserve ajqieared to be tlie obvious" solution and a survey of the area had been carried out. A plan and an estiniiite of the cost of the work was beiug prepared. Walton Park Erosion Advice was received from th'e Loil ( 'onsen al iou and Rivers Control Councir tliat an additional grant oi' £22 had been made to cover expeuditure in oxcess oi' the estimate for the corree tion of erosion at Walton Park on the Mangatainoka River. The sum of £2i)U has already been spent on t.his work, the amoiiiit beiug a free grant from Ihe couneil. In regard lo McQuire's erosion at Siunrt's Bend in Ihe Manawata River, .Mr. Baly reported tliat further erosiou ; of Ihe bank occurred during the recenl llood and tlie river at this point was only a few chaius uway from a farmhouse and the road. As serious daniage could resull from another llood aud the cost of rcpair work would have been iucreased, it was decided to proceed with the profeetion work. An inspection of Walker 's Cut was made on .lune .'!() while the river was ilooded and it was observed tliat the cut was functioiiing quito well.

Beveral inspectious had been made of Cowdrey's erosion and the positiou appeared to be deterioraling with each llood. X'aluable farmland, as well as city couneil property, was tlireateued. The problem of protecling this aroa became more diliicult aud costly as timo uent by. Alternative sclienics had been forwarded to the >Soil Conservation aud Rivers Control Couneil for their approval and a subsidy. Plans for Ohau Klver A survey covering approximutely two miles of tiie Ohau River had been conipleted. The section of river surveyeil was located between the foothills aird a point half a inile downstream from tlie railway bridge. This river had a fall of feet to tlie miie along this section ; and had seriously eroded Jirst chiss ' farm laud on botli banks and was threatening the abutiuent of tlie railway bridge. At a point aliout half a iiiile above the bridge tlie shingie de-

posits were bank liigh aud a major break through by the river was imniinent. Tlie pi'opost'd sclieme was to divert ihe river into ihe old ehanuei, conslruct several training groynes and stopbanks. The groynes would be construcled with iron rail piles driveu to a depth of 10 feet aud would be fueed with trees. This tvpe of groyne had proved niost successful in other partof this river. Tlie estimated cost xt the work was £1500. An inspection of ihe head water of the Ohau River was carried out by tlie Afforestation Conunittee during June.