OPINIONS ON WAIHIRERE.

Gisborne Times, Volume VI, Issue 156, 13 July 1901, Page 4

OPINIONS ON WAIHIRERE.

In the course of the water supply debate at the Council meeting last night. Cr Lysnar quoted opinions which he had received in regard to Waihirere.

Tiic questions referred to by Cr Lysnar were as follows : 1. How long have you been in this district, and are you intimately acquainted with the nature of the soil and its formation in this district generally2. Ho you consider it is practical in this district to make a dam and hold water in it. depending only upon the natural foundation of the country to stop the water percolating or wasting away through the surface behind the dam covered with water ? 3.

Do you consider it practical to make such a dam in the gully above Waihirere halls, so as to absolutely rely on holding ail water caught for any length of time after an allowance of, say, 00 per cent, for percolation or absorption has been made at the time of catchment of the actual rainfall in the locality? 4. What fit anything) in your opinion should be done to make certain of the water being retained behind such a dam without loss, for any length of time ? 5. What would be the effect (if any) assuming that the dam stood and the water was retained behind it upon the kills against which the water is backed ? Jilt 1\ MCLOI’ttULIN. The following replies were received from Mr I’. MeLouglilin, contractor :■ — 1. Sixteen years. 2. I do not consider it practicable withoutconcreting. o. Ido not, as there is no solid rock in this district to my knowledge; even the limestone rock at l'atutahi is full of shakes. 4. It must be concreted, 0. Ido not know. Jilt THOMAS BYIiXK. 1. Eleven years, road contracting all tiie time. 2. My experience is that brown papa or limestone in this district is very broken and shaky, but the blue papa foundation is all right. At the lhitutahi quarry the blue papa foundation is right below tiie limestone ; this is to be easily seen there. o. I have never had ail opportunity of seeing Waihirere and examining it; but I would uot like to live under it if a dam were built there. 4. To open u)) the whole of the foundation of the proposed dam, and see that all broken and shaky rocks are removed, until you work down to solid foundation ; this may be costly, as you may have to work through a good distance of shaky rock, 3. If the hills are steep the water will soften the bottom portion of the soil, which may cause slips, and till up the dam, and that may require dredging, and bo expensive. A. MCKENZIE. The following replies wore received from Mr A. McKenzie, a well-known settler of Ormond :—l. 1 have been in the district over thirty years, and hftvo lived at my present place of abode all the time, thus having had full opportunity of judging the Waihirere country. 2. No ; so far as my opinion goes, you cannot, o, 1 do not consider that it would hold water, because the country is too broken and rotten, and the foundation is not there to hold water. Besides the water would break through and come out below, as you see it generally does all over this district. As a proof of this, the creek behind my house comes from the same i ranges as Waihirere, and in the summer time it in places runs into the earth and [ disappears altogether, thus showing that the ground is porous ; further, there is also a natural dam made by a slip about n mile behind my house in the hills ; it would hold about half an aero of water, i but in the summer time it goes almost dry, and while there is no water running over the dam the creek is running bclow : thus showing that the water percolates through the hill. Lot the Councillors come and see my creek, and I will be able to show them where the water runs away. 4. I would not like to say, because I do not think it safe to put a dam . there at all. 5. It is no use my answering this question, because I am positive thal the, dam will not hold water. MI: O. MALONE, CONTRACTOR. 1. I have been a resident hero for 22 years, and am intimately acquainted witl soil and formation of this district. 2. J think that it is not practicable to make i dam and have water behind it in this dis triet. d. I have quarried over iiOOO yard: of stone at the Waihirere quarry, am consider that a dam cannot be built on tin present surface to hold water, as there i: too much louse stone and rubbish in th< bed of the creek, which will cause tin water to drain underneath. My experi cnee of the rocks at Waihirere is thal there are some largo loose boulders in tb< hill, from 15 to 20 tons, altogether do taclicd from other rocks, and covered uj among earth and loose rubble. The for niatiou here is strange —you will find t largo extent of good hard stone there three yards below that you will conn upon very soft stone. 4. It would b( necessary to excavate down to the solic rock and then make a bed of concrete up to the base of the filling. 5. I do not . think that it would have much effect.

AN KNUINUEIt’s OPINION. Mr W. O’ltyan telephoned from Waipiro as follows:—1*. Have been in the district 25 years. 2. Everything depends upon the nature of tho ground. There is some country in this district which will hold water, as for instance llcpongaerc Lake, Kcmpthornc’s Lake, —■ — Lake, and others I know of. Whether the water would percolate behind tho dam would entirely depend on the nature of the under ground. Assuming the ground is suitable, I consider it practicable to make a dam. 3. It would be impossible for mo without any data to make an absolute statement. I see no reason why a dam could not be built to hold. There, is very little experience of dams in this district. I have built one or two hero in a small way. They have hold water up to the discharging point. Everything depends on tho country being suitable and solid. Tho dams I made have iilled with silt, but I made them so for road purposes. 4. It would bo impossible to answer this without knowing the nature of the subsoil. 5. I do not anticipate there will be any effect of any consequence, the ground having already assumed its natural angle of repose. Tho ground would bo likely to retain that angle under water as well as over it. I think tho soil would have a natural tendency to slip above, but I think the pressure of the water would help to maintain it in its place.

MR E. DEVF.EY, MAXGATU. J. Have been in the district 29 years, and am well acquainted with its nature. Have been contracting in road work on and off all the time. 2. No, I do not. 3. No, 1 do not consider it practical; and, further, I think if would bo a risk of life to tho small settlers underneath through the danger of it breaking away. The country is so rotten I really would not like to sleep under it myself, as it would be, so dangerous. 4. To go down to the rock and b'uild all over tt with a strong concrete foundation or something to substitute it. 5. It would only bo a question of time when the dam would get full by slips or siit. I know where there was a large slip which caused a dam at Waipaoa about six years ago. Behind the dam it got tilled up until the whole thing was washed away bv a flood.

V.Ji e. gray’s opinion. Without replying categorically to your questions, I will give you my opinions about the clam in question. I have lived in this district since 1878. I am intimately acquainted with the nature of the hills adjoining the proposed dam, my house being within about two miles of it. I am of opinion that if the dam is made, in course of time, probably some time within the next 20 years, one of two things will happen-—either the dam will silt up or the water will break away on ono Of other side of it, the consequence of Which will he most uisastrous 10 seiners living below it. Few people would believe the eti'ect of water scour on these hills unless they had taken particular notice of it. We are subject in this district to very heavy falls of rain over a limited area. One such fall occurred in 189-1, when I consider about 25 per cent, of the surface of the hills on my land was washed away. Some of the effects of this rain can be seen to this day where the big slip occurred on the Waimata road. If the Waihirere water is taken to supply Gisborne, where is the water to come from to supply the needs of the settlers along the Waihirere creek'? The farmers adjoining the creek are dependent upon that for the water supply of their stock, and if this is taken away, which it assuredly will be in dry weather, it will be a great hardship to them.