DRAINING THE TAIERI PLAIN.

Otago Daily Times, Issue 14461, 2 March 1909, Page 2

DRAINING THE TAIERI PLAIN.

ENGINEER'S PRELIMINARY PKSPKCTfON. AN INTBRT-iriNfi REPORT. ■ The Taieri Drainage Hoard, at its meeting yesterday, received a report from its engineer (Mr M. Klliott, M. ]i.rt. 0.K.). on the question of draining its- district. Tbe rp|»rt [which is given below] contains much interesting information and many valuable suggestions, ami shows iliat Mr Elliott is attacking his enormous task in a maimer ihai augurs well for its fiucce-s----ful completion :—-

TilE SIM'KRRTREAM PROBLEM. Since the last meeting of the hoard I have maile some investigal ions relative to the discharge of the Siivcrstream into iiio T.'iieri River. Levels .of the country have been taken between Uladfield read ami Allanton, Tlit- eouise of the .S-ilversfreani a f Gladfield road is undefined; the wafer spreads out over the country and finds its v.-'iv to the river bv two separate courses. 0110 of theoois at Mr Win. Shanil's house, and appeals to be the original course. The other is known as the straight: cut and is situated about half a inile farther up tho Taieri ltivcr. There also discharges through llicfp oullels various streams from the East Taieri district, the "largest, being the Mill Stream. I find that the levels of I'm various points between Gladfield-road ami Allanton are as followstor convenience of reference Iht; levels are reduced to a temporary datum and will ho reduced to low water sea level later wl>er. isucli has been ascertained, 'flic level of the water in the Taieri River at- tbo mouth of straight cut 37.95. The level of road bridg.o over straight cut. 100.00. Lowest level of land in lagoon 91.00. vSilverst'ream lx>d Gladfield road 103.00. Mr tvirklnnd's verandah 107.11. Mr Win. Sh'atid's liottio 10181. Water level Taieri River at Mr Win. Slnind's 87.51. Red of Owliiro Crock 011 road C3.OL Rail level Gladfield station 102.10. Lowest point on Gladfield read between Silverstream and station 97.40. Tied of drain 011 Uhidfield road culled centre ditch 52.55. Junction of loads centre Mcsgiel, near Mr Kirkland's, 101.10. At junction cf centre Mosgiel road and Riocarton roal 119.12. Bridge at Allaaiton 105.01. Level. Taieri Kivcr, Allanton, 85.67. Tlio fall of Ihe river from the upper and lower inlets of tlio Silverstream lo water level at Allantojt is 2.81 and 1.81 respectively, the distance from the upper inlet to Allauton being two miles mid tlio lower one inilo and n-half. The flood level at the housa of Mr Kirklnnd is 106.50. There may possibly lie sonic tidal influence in the river at Allanton which will bo subject to further investigal ion. AN OUTLET FOll SILVERSTREAM. From the information obtained it is obvious that there is not much to be gained by carrying the .S>ilver»tr?am to Allanton. This brings the, problem lo the discharge into the river by t.ho original inlet at Mr Shand's or the inlet known as the, straight cut. Tim objection to llio straight cut- inlet is that, the course of the Taieri River at that, point is unfavourable for a junction. At present the Taieri and Silvoretream meet, from exactly opposite directions, so that it will be necessary to curve tli« junction of the river and use soino protective ivork. The direction of course; at Mr Shand's are dcoidvdlv more favourable, hut there is not much room to work in between the buildings of Mr Kirkland and Mr Shand. There is also another consideration in favour of the straight, cut junction. There is a depression here which permits the water from the Taieri to flow out anil submerge a largo area, of land. Under present conditions a nee of 4ft in the Taiori will swamp the lagoon. A rise of 9ft will put water over the Übultield road. A rise of 14ft will covcr ibe rails at Gladfield station. The depression- in the natural bank of the river in the vicinitv of the straight cut sweeps back in a, crescent shape with a dip at the. crown of 12ft, so 1 hat with a rire of 10ft above the present river level, there is a. considerable area for cscapo for water from tlio river. This area, increases as the river

rises. It will be necessary to construct im embankment here to keep Iho river water in.

PROPOSED ALTERNATIVE SCHEME". I propose to prepare plans for carrymy the Silveretronm out at the alternative points to ascertain Iho most suitable scheme to he adopted. If the Silverstream is carried from the (4ladli"ld road to the Taieri t.hero will require lo be some provision mad?, for the di.sno.-at of the waters of the various streams on the north side of the Silverstream. The bulk of this water will have to bo turned - into the Silverstream on the east side of the Gladfwld road by au embankment chaiuid. The remainder will bo syphoned under the Silverstrcjir,, and carricd down to the Ov.'hiro and pumped into'it, except at times when iho river is at summer level, such as at_ present, or slightly higher, v.ihon it. will discharge by gravitation. The drainage on the south side of (lie Silverstream and between it, and Owhiro, which is small, will bo treated in a similar maimer."

works necessary on the own 1110. The Owliiro will require enla,rgfin" and embanking. II also discharges "water from the Taieri Rivor upon the plain to a considerable extant. At Albmton tire Owliiro is a well-defined channel. Tiio baaiks are sft higher Ow. tho hind a ntiW and a-lialf tip the plain. The Owliiro is not a difficult problem, tiiul will not lxj an cxpsmivo streaiii fa deal with. The Silver-st.i-e.im carries down a largo <|uantity of gravel which necuniulales on Ihe slack grade;. This will be it source of trouble, and prov'-sion will liavo to be made for liftmif it out or eke timdinu; the channel up. TIDE LKVKLS |\ TIIIC T-UFIU All examination ha s been made' of 11,0 mlo levels at Henley „e,| I,„k.- Waipori. The range of ~ |„1„, al Tlliori A| ' omh is 411 nin. Lhc, rumfe at mud bnd"o -,t •Maori km It Springs 2ft 2ii„ ]f( 10in; railway bridge ]ft Uin'. U t 'Sin; outlet at r.iihc Waipori Nprin<- lft 4im, neap lft 2iin; at .unlet of Waipor, River info lake; lft 3in; hridi;e on llenlev to Berwick road, S.lin; at lierwick, 3iii Mr .Stevenson, of llenlev. has sent me -i plan ratio by Mr T. I Wham : copy is also in the Public Works Otliee. This plan was made in 1894, and shows Ihe maximum depth of l,uko Waipori 3ft Sin below low water. It. also stows a number of bench uutrlw and sectional lines Unfortunately there are no levels on the plan. Mr Furkorl: has kindlv written to obtain III? information Mr Porlmm proposed to imi lie a new out let from Lake Waipori from Iho outlet into l!u, Creek, across to tho prc-ssnt slictiiu-a. distance of about half a mile. There will bo no difficulty in keeping- Hie tide out of Lake Waipori, but since the range is only Iff the, lotvcriiiff of Elio lake will rot 1,0 considerable. TO RECLAIM LAKE WAIPORI. It, lias lieen proposed to reclaim Lake Waipori. Possibly fiie lake is more silted up shice Mr Perliam made the survey. Thero is no difficulty in the w;i.y of const melius u channel for Ihe Waipori River through the lake awl embanking- it in. Investigations will require to be made as to tho value of the soil for cultivation. THE RIVER. AT HENLEY. A Survey has been made at tho erosion of the liver bank at Henley.. The survey shows that the river is considerably contracted at the point, and a large bank of sand has been de posited on I ho south side. This has been causjd by willow tree s blocking the former ehannj. The depth of the river at 40ft from, the bank i.s 19ft. The present embankment is considerably damaged, and will require to be moved further from the river. This will require about- an acre of laud. Mo far as I have ascertained by the sections taken, l!! 3 under-waier slope is about 2ft ]in. The sandbank on the south side of the liver in to bo- dealt with in some manner to bo determined after further examination. There is a fense along the outside of ihe hank which is broken down ami in a bad state of repair. The fence appear.; to have been moved out to allow Ira flic to pass the broken part of the tnib-ir.kment and connect with a road. At present, it is not in a state sufficient to prevent, siock crossing it. The damaged part is about, five chains in i length. VARIOUS REMARKS. I have itispecUd the timber stacked at the Otokia manse, tit:d have made an inventory of it. There is also a stock of l'K>!=, qum-Ujois, and nails in the county hut which lo hoard. Mr (!ibson wouo-es to creel a pump on the outlet drnin near his farm, so a." to pump '..lie I from the Unci; Creek into the river I at this |wi:ii. l'lie j.r.uip i.s at pr<>:-nf near the ruined wheel pump. It. would be aji. advantage to bave the pump erected

anil ready for life in ease of need. There is no on.uin? attached to llio (jump. Tlio poMtoi; iii which it is propo?cd to crcct ill" pump is within a short distance of Duck Creek, and would do some good when ill working order. At ilie same l imp. it. is only a suggestion to make us?, if possible, of some of tin- plant Ou the lands of the board. The erection of the pump is only a temporary expedient. Mr (til.son drove me to <or- a drain leading front Kirk's drain lo the wheel pump at. the little lake. Tins is a <111-111 drain carrying the wnK-i of a large drain. The urain is undoubtedly in a tad state, ami cleaning may do some good. At the same liin? ii >s uselessly small. The repoit was rawed.