WATER AND DRAINAGE.

Manawatu Herald, Volume XXXII, Issue 803, 25 January 1910, Page 3

WATER AND DRAINAGE.

[to the editor.]

Sir. —As the question of water and drainage are now being energetically pushed forward by the Council, I think that a little healthy criticism would stimulate interest upon the subject, so I crave your kind indulgence for a short space. As the first proposition I would say that ihe water scheme could be considerably reduced, and the surplus added to the drainage scheme with far better results than at present proposed. The first consideration is, of course, the artesian well, its size and position, a six inch pipe is proposed, but I think a four inch pipe as a trial bore would be better, as, should there be obtained anything like an ordinary flow of say at least 50 gallons a minute, that running for the 24 hours would give 72,000 gallons, more than this township could consume in the time, for many years to come. The Christchurch 6 inch wells, just installed for the same purpose, give about 190 gallons a minute or nearly 270,000 gallons in the 24 hours, a perfect waste for our small community. The storage capacity of the two tanks proposed is 150,000 gallons, 75,000 gallons at high pressure supply, at the top of a stand erected 116 feet high, and 75,000 gallons on a level with the well, for a reserve to pump from in case of fire. Now, as we could not use 75.000 gallons in the 24 hours, it would considerably reduce the size ot the staging of the stand to put a lank of only 50,000 gallons on the top and the balance of 100.000 gallons in the J'crro concrete reservoir on a level with the well. The 116 feet stand could then lie further reduced in cost by about three-quarters (or say twothirds) by doing that, and by placing only the top 50 leet of it, on the top of the highest part of the Ferry Hill, the height of the tank then would give us ample pressure for all household purposes, and quite enough for a couple of hoses to put out any fire if taken In time, or at the worst would keep it in check until the engineer got the pump connected with the mains, and pumped direct from the 100.000 tank on a level with the well, which would be continuously running into it, but not perhaps as fast as it could be pumped out. The hydrants would theu be brought into use and the fire soon extinguished. The position of the well is a very important question, from the specifications I see that it is to be on the Ferry Reserve, so I presume that it will be placed on the high ground at the back of the Pound, but we should be warned by the failure of the artesian at the top of Main Street, aud not make any more expensive experiments. It would be certainly better to put it at as low a level as possible, and let the extra power of the pump used do the extra raising of the water, which in this case would make but little difference. I am convinced that it

would be more reasonable to expect a better flow to the surface at a lower level, so if the well was put down opposite the Pound, below the roadway on the river bank, we may almost be certain of getting an ample flow of water into the 100,000 gallons tank that could be excavated there, the debris from which would make a good roadway around above high water mark and provide room for a pumping plant instead of placing it any higher up, a force pump can derive the water higher if it has not so far to pump it from. The coke gas engine proposed for driving the pumps is much cheaper to work than either steam or oil, but if two engines were required, as proposed, to provide against a breakdown, one could be an oil engine, as it could be started much quicker than the others in case of lire. Now comes the question of the size of the pipes, as the specifications say 9,8, 7, 6 and 4 inches, perhaps 8, 6 and 4 inches would be ample for any increase of the population we are likely to get for the next 100 years, and it is not wise to burden ourselves too much to the advantage of our posterity, who in all probability will be far better able to bear the burden than we are. With regard to the drainage scheme, the old adage would very well apply viz., “The proof of the pudding is the eating,” as from the size of the pipes proposed, and the impossibility of getting a necessary fall, without resorting to artificial means, it is very problematical if it will be of any use without constant flushing as proposed, which could be easily done with great force from the water mains, but if that is resorted to, too much solid matter will be forced into the river to float past the mills on the outgoing tides- I think it would be better if a main 12 inch drain was carried through Johnston street from the Avenue Road to the septic tanks in Purcell street, and the 10, 8 and 6 inch drains connected with it, from the Main, Union and other streets as required. As I should say that the 9, 6 and 4 inch drains as proposed are too small, for the fall, from 4 feet below the crown of the road at the top of Main Street to the level of high water mark in Purcell street, is very small indeed for an effective run in small drains. Again, as too much clear water destroys the effectiveness of the septic tanks, it may perhaps be better to lower them below high water mark to give a better fall, and install a pumping plant instead, to pump out the one that should be running into the outgoing tide, were the levels sufficient for the purpose. Apologising for

intruding so much upon your valuable space.—l am, etc., Aquarius. P.S.—Since writing the above, I think that if even the 12 inch drain in Johnston Street is too small, if 3.000 people are expected so soon.