SURFACE DRAINAGE.

Hawke's Bay Tribune, Volume II, Issue 52, 14 February 1912, Page 3

SURFACE DRAINAGE.

Till: <()’ TliLV'.'l) L‘i: A I V. COST ()[’ IMPiIOVEI) MAi.\ TL? AM’E. A VEXED D-UESTIOX. At the Etv.-.k-’ Er.;. < '.. tnty (ir.in eil meeting yesterday the question of drainage came up upon receipt ol the foliov. ing letter, dated Btli February. from the Hastings Boroue’u Council “In regard to lire proposed ex penditure of L’lsOO by your council in enlarging the Southland Drain. I am directed to inform you that the sub-committee of the Hastings

Borough Council held a meeting this morning to further consider the matter, when they passed the following resolution: “That tliis committee eannot recommend tli'-ir council to contribute anything to the cost of the proposed enlargement of the Southland drain, nor yet to the purchase of any land in connection therewith. In support of their decision. the sub-committee direct me to call your attention to the -III: paragraph of All - . Kennedy’s report in n hieh he s;:.vs : — “During last week's tery heavy rain 1 inspected the locality and. found that the drain was ad ing well and meeting requirements.’’ In the opinion <•! the sub-i ommittce the foregoing paragraph indicates, that apart ij ;.a the dra: shm ■ f the Al;.' or.t ami Raureka setJerm-nts. which is no concern of the Hastings Borotign Connell, the drain as it is at present is of >.t’ffit-i.?ut size for the st 1 eel drainage f’owitur into it." Ln view of the difference of opinum between the two bodies it might be well to publish th? report which reads as follows : - This coum'-’tlee auroe t.-> r - com mend, to their respective Councils, “that the wotk of improving the Southland drain from the river to ’Maraekakaho road 1 e proceeded with in aecordanc:- with the svhcnr prepared by Mr. Kennedy that the Government he asked to pay hail the cost of the necessary improvements win re Ci own laud bounds the drain—and that the E- rough and Countv Council each contribute halt trie cost of tb.e work. The Government grant of £l5O to be expended on the above-mentioned portion ol the drain and half of the sum is *o be credited to each contributing body. —.Signed. Thomas Crosse. Southland Drain. —Air. C. D. Kenre(lv. County Engineer. r< ported as follows :— ”I have go're over the pro-

posed ueitr.ihin to tne noi.:i. through part of the borough. Laving its outlet at the Washpcol. If the country traversed by this propose.; line were not subdivided into small sections with numerous roads it would ha vp been a better line ■ u adopt as it follows the natural slope of the country and saves distance : owing to close settlement and the cost and inconvenience of taking a large drain through Hastings and its suburbs. 1 regret to say that this route is not practicable. 1 have also given further cons’.deration to the district engineer's proposals and bad some holes dug on the old Xgarurore river bed along and near his proposed line, tiie water rose freely in the h-'les to wiihiu a few iir.dies m the surface, with a perceptible movement downstream, and this at a point where ;t was necessary to make a drain over five f >et deep. 1 reluctantly advise you to abandon this scheme. There now remains the present line of dram. 1 a n toi.t that last year the dram was in a very foul eondiiin.i. m>t baling been cleaned tor over three years. a-u. also that the rainfall was abnormal, very heavy rain falling while the ground was thoroughly saturated. The drain was cleaned last spring and is at present being cleaned in a very thorough manner but the work is only partly done. Dta'.ng last week’s very heavy rain 1 inspected th.e locality and found that the drain was acting well and meeting requirements. Tiie drain is uneven in section. tb.e width on the bottom varying from *1 to 8 feet anil tb.e side slopes from vertical to 2 horizontal and 1 \eiliciil. .Flirt cquai tei s ot a niiie through sandy ground have bee.l planked to a height of -tfi- tint Al itch of this is decaying anil requires renewing ; in addition a simitar distame requir. s support. 1 consider it advisable to use concrete

.-.labs in future ; culverts cross th? Alaraekakaho road and the itulway line do not provide sufficient waterway and iiiust be enlarged. Numerous slip.s have taken place since the last heavy rains. The notes and sections on the attached plans s tpply further details and it is Lar-by rca sonablc to e;-:pcc!. provision to be niad ’ for a dmin that, will immediate! v carry away tiie whole of an abnormal rainfall, but it is neers-

,-arv to provide drains of sufficient capacity to cairy the whole ut uie water during moderately heavy rains ami to provide quick ri kef after iraordinary rains. In calculatirg the capacity of drains in the fr-n districts- of Lincolnshire th? old engineer provided for the due to the water arising from a continuous rainfall of a quarter of an inch o> rain in 21 hours, making no deductions f<zi- soakag? or evaporation. This calculation was also adopted by Sir John Hawksbaw fur drainage of the East Ten ami by Sir John Cood? for the drainage <>t the North Level. In Holland the quantity vafim- from s to i of an inch of rain in 24 lioui-,. In Ireland for the hathdowny drainage. provision was made in the channel for a discharge ot C'X) cubic ffi t per square miie per minute, equal io a continiio-.’.s rainfall of about of nr. inch in 21 hours-the soil being a deep alluvium. Owing to the torr-Ptial' rain these allowances would not Mifiice in this country am! it would not h? advisable to allow for n rainfall of les:- than j of ar. inch in 24 no-ars. making «:<• deduction f >r tu-.ika.ge or evaporation—the present drain at its crossing with i’-f Maraekakaho road lias t» dischargo the ot-r Lorn r.b.mt 4-r.Ni a. r. 7: of an inch of rain in 21 b. over this area i< eqv.ivab'nt to 7500 cubic feet per minute which *o-atd be accomplished by a drain having a fall of five feet in a mile.

jfl. wale on the bottom, having sale ■slopes of to 1 ami running -lit- Gin. dcr-p. If a drain of these dimensions were kept thoroughly dean it would in my opinion cany all th? lamfal! during a period of heavy ram and afford quick relief after abnormal rain. 1 estimate the cost of enlarging the drain to a uniform capacity as suggested above, replacing decaying timbering with concrete slabs and further similar wo; k v.here n<‘cessarv at blStiO. In :vldit’.nn to this, provision should be man? to, an annual expenditure of £2OO toi repairs and to enable the dram to be kept thoroughly dean.’’ After dealing with the matter of tb.e Southland Drain as reported in our report of the Counly Council meeting, the chairman said he considered it was time the council went into the vexed quest ion of dtainage generally. Their solicitors hail advised them that it was their duty to look after siteh constructed drains as affected the roads, while it was the duty of the Riv, rs Board to look alter all natural water-courses. It was time they had a conference with the Rivers Beard and arranged to keep these drains in order. It was

dearly the duty of the Rivers Board io keep all natural water courses jr. proper condtf ion. C’r. Gordon concurred and gave ■lluslration of how dillicult it was to do any good while dealing with individuals.’ it v.as impossible to arrive at any finality -in the matte: - . Cr. Cruse was also of oninion that the Rivers Board should be conferred with. In the past they had 'o deal with nearly all Ing holdings ivhile now t.nic'i of the land alfeetrd by these drains was held in small holdings, and it was time th”y arranged for a clearing im. The conference will be held.