THAMES NEWS.

Thames Star, Volume XLVII, Issue 10380, 6 December 1912, Page 4

THAMES NEWS.

THAMES HARBOUR IMPROVEMENT

THE KAUAERANGA CHANNEL.

BNiGPNEiEIRi THOMPSON'S 'REPORT

ESTIMATED COST £14,000

At the special request of several j \ Thames rpsideiilts interested in tdie i; question of harbour improvement we pubjlisihi in full the special report submitted to the Thames Harbour |' Bttilrd by Mr J. 81.B 1. Thompson (drain- j' ago engineer) on tihe feasibility of j 1 improving the Kaiuaea-angi.'. Channel. .' and thus niiakinlg 1 adequate harbour j provision at Shortland. A summary i of the report wias published! at tihe '; time, but in view of the fact that | the Htarlbour Bbturd again discussed , the proposals, we have been, -request--; ed to furnish the report in. detail. In it Mr Thompson says: — . 'In accordance witili Jthe instructions of the Under-Secretary .for : Lfiimds Thereafter bag 1 to report up-j on. the feasibility of improving the j Kauaieraaigial OiiOiiinel. Owing tohit ray pressing matters I have been tunable to supply the report to yaw Bbard um|til the present moment. DATA AVAIL.ABIL.EI R£! KAUAEi- ■ KiAN^A CHANNEL*. I ha.ye had obtained by my staff such longitudinal and ciross-sections of the present channel as circumstances permitted!, but as no records j of borings whatsoever were avail- I "able in your Board's office I halve! therefore' had to assume the under-! lying strata likely tp be met with,as, the work of putting; cUrwn .borings could not be done by this Depart-. memitt." -•■■■■ .... _;■;_._ ■;;■■ GENERAL. • ' ' . .Before making any suggestions as . to the practicability -of '■ improving the Kauaeranga .Chainnel, • I may say that' I have carefully read the letter forwarded to me toy your secretary, under date of Novemiber 17th, 1911, wherein wias outlined the. matter , that it was de&ired my report- should , cover, aaid'hare to state thaiti as far as making tihe channel available for , the lp.s>. Wakatere is concerned, I have decided! not to go into this ■•matter. I am of the opinion that . ."thei" project would b© very costly as it would, be useless to think of simply, dredging a very long- channel lip to ''S-hprtlaiKL Wharf, without taking!'"pre'claMtiions t*> miaintaini slame against silting flroin itihe extensiveniudba'niks/ Again, a; turningj basin of exceptional area would havb to be mlade at the Shortland Whairf, and I need hardly point out the difficul-. ties anS expense of keeping this cilear of silt. . Generally speafeing, I oonsidei* thaiti youii* Bbai-d should; go- fulV into the whole question of harbour accomtmod'aitioni, nia.viga.tion', and for shore improvemeiits a« a; whoie, and not tio dd any,work unilessi it formr ed part of future projectedl woiflsai. Any Very material giain in naivigation: ,bff ithei Kiaiilalei I'aai..giai Clharewiet, must be an ercterjsiv'e w-ork, and the !?ugge*st{e!d) im-paiovteanenltisi , that 1 hihall mialde are limited in. scope by the outside tidal a.n'cl physical conditions of your foreshore, aaid it is a. question whether the • wpproxiniiatc co'rit of same wifKi-ld wiarrant your Board jri proceed injr with same at all.' .■,■...-" -PRESENT- CiONDTTIOK Of TH' r|

. . .KATJAEiR,ANftA CfILANMSiL At the present time ...the. above channel is sufficient for general purposes working from the most seaward end of Slim-bland Wharf upstream, and it is from, the same end of wharf working 1 down.stream* that trouble is experienced ill. s-ui*essfu!iv naviga,tinigi stune. Tliiei miaiin trouble lies in the vast expanse of miad flats met with between the wharf and low; water mialiik, aad through Avhicli the channel takes a moire or less tor-

tuous course. One great obstacle is the accumulation of gravel deposits in the bend nearly abreast of the "lamp-post." Asia-swell-known this gravel is carried down during periods of freshes, iuid is a trouble that will always be more or less experienced. There are also in ■ all probability , many submerged snags embedded in the shingle drift. From the l.ongitudin-

' al and .ciross-sp-ctions it will be seen • : that, the existing chaoinelie of vary- ' ing depth,, and tbaft there is' greater depth of water at the^wharf .breastwork. It will nilso. be. noticed, that low" waiter mlark at tide wharf is mot ' in aoobrd with the same nilaa*k u'f> say the 18in lines but is about 1.7 above samel; this is largely .tvccounted for by the gra.rel bar which, tends to keep the level of wlater at wharf up. Stt'GOEIST!E.D IMPROVEMENTS. In Older ito improve the' channel the proposal is to dredge a channel straight from* the end of the present wharf past the lamppost until the cut ..strikes the present channel again at the point marked E' On plan,, a distance of 2900 ft. The dredging, however, yroufd 1106 Have to be. carried--out for all this distance as the channel- is at the present momentdeep enough for boats of seven feet draught, for a distance of S&O'ft from ■tjb© ■ wharf, toward^''tihe lamp-post, which leaves a distance of 2'lOOft to be dredged. A new channel dredged from this point 60ft wide on bottom with the presenjt bottom of the channel at B and would be about one foot deeper, bringing 1 bottom, grace of new cut or to line shown as 35ft above datum) would give a navigable depth of at> least Bffc throughout at high w'atar on all ordinary tides, and would allow of launches drawinig 3ft of water to work the channel easily afc all half tides. Beyond point B I do not suggest that at tihe present i stage anything else in the, Way of i dredging be done, as in all pro- i