Sessional_Paper_1902 — Page 882

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weather flow, at or above high-water mark spring tides, and conveying it into the If this were done the nuisance would be mainly that due to filth washed in by the tide and the wind.

sewers.

of drains.

19. Without having a complete record plan of drains and nullahs it is impos- Record plan sible to make any definite and finite recommendations as to the amelioration of the drainage system. When the scavenging of both sewerage and drainage systems is under one and the same Authority, a material improvement will probably result.

20. I will now briefly recapitulate the recommendations which have been made Recapitula- with regard to drainage in this and previous reports.

(a.) Let covered drains or nullahs be avoided to the utmost extent

possible.

(b.) Let the inverts of drains, at their outlets to the sea, be at mean

sea level or higher if possible.

(r.) In the case of flat areas near to the sea, whenever covered drains are necessary, as in the case of the Praya Reclamation and other Reclamations, let them run by the shortest possible route to special, outlets to the sea, and do not attempt to connect them to main drains or nullahs which are tide-locked.

=

(d.) In laying out new districts let the alignment and levels of streets be so planned as to minimise the length and size of underground drains. (.) Let it be remembered that the main object of sewers is to keep sewage out of the drains. It is more important to exclude sewage from the drain than rain-water from the sewer. With the gradients which obtain in Hongkong it is almost always possible to provide storm overflows should any sewer become gorged with rain-water. (f.) Let a complete Record Plan be prepared of the drains of Hongkong, covered or otherwise; this being in existence a definite scheme may

be prepared.

tion of recom- mendations.

21. I have not in this and other reports concerning the sewerage referred to Sewerage at Kowloon. I have altogether refrained from so doing because I look upon the Kowloon. sewerage system of Kowloon as provisional or temporary only. It may not .be necessary to carry out a complete scheme of sewerage for some years to come. Nevertheless, I am of opinion that a definite scheme should be prepared and adopted so that all work done may ultimately fall in with the sanctioned scheme and so that nothing done, or to be done in future, will require to be undone.

ment of surface Irains.

22. I have recommended that surface water be carried off to the utmost extent Arrange- possible by means of the side-channels of the streets, or other open drains. There is a little difficulty in so doing in the matter of intersections of streets.

One way of dealing with the matter is shewn in the following sketch :-

A

C

D

B