70
torrents have in numerous instances been violently diverted to avoid interference with public or private property, and in some cases instead of following the line of the street the culvert passes by an indirect route under houses and occupied areas. Recent experience has afforded convincing proaf that the natural order of things cannot thus be departed from without the risk of serious damage from flood. Unfortunately some of the mistakes of the past are not susceptible of an easy remedy.
Other damage within the City.
27. Besides the serious damage in the Albany and Glenealy Nullahs, the Tsing Kai Lane culvert in Wanchai was blocked and the neighbourhood flooded. A considerable laudslip from the cliff on which the Naval Hospital stands completely blocked the road to Bowrington and the Cemeterics, and another slip on the north side of the same hill destroyed the back premises of some Chinese houses. On the south side of Queen's Road East the back premises of several Chinese houses were destroyed by landslips from the steep hill side which rises immediately at the back. The approaches to the Bowrington Bridge at L. on plan were carried away.
28. In the western districts of the City considerable damage, though not of a serious nature, was done on the lines of the Po Yau Street, Richmond Nullah and Shek Tong Tsui drains. town the nullah which discharges into a culvert immediately above the Cattle Market overflowed, At Kennedy. and the water swept through the market destroying the boundary wall. A number of minor casual- ties from landslips and flooding occurred but none calling for special notice.
Tytam Water-works (Reservoir and Aqueduct.)
29. The nature of the accident to the service tank in the Albany Nullah has already been de scribed. Some 21,000 cubic yards of debris were deposited in the tank itself during the storm. The tank averages 230 feet in length and is 200 feet wile, and 30 feet deep. It has therefore a gross capacity of about 46,000 cubic yards. This solid deposit tended to reduce the pressure on the sides. Immediate steps were taken to further relieve the pressure by lowering the water level in the tank. It is satisfactory to be able to record, after careful examination, that no settlement whatever can be detected in the concrete structure, nor was there any leakage from the tank.
30. Along the line of the aqueduct which is carried under the surface of the Bowen Road, several landslips took place between the service tank and the mouth of the tunnel, a distance of about three miles. Of these, three were of formidable dimensions. They occurred on the steep hill sides above● the level of the aqueduct where it overhangs the Happy Valley (at M. N. O. on plan.) The debris swept across the road and aqueduct carrying away the roadway, and the superstructure of the aqueduct, for a length of about 120 yards. Fortunately the foundations remained intact, and consequently the repairs of the aqueduct present no great difficulty, either as regards time or cost, and are in fact now nearly completed.
31. Mr. COOPER estimates that during the storm at least 30,000 cubic yards of earth were carried by these landslips across the line of the aqueduct. This included besides earth, a large proportion of huge granite boulders, dislodged from the mountain sides, some of thein many tons in weight. After crossing the aqueduct the course of the principal land slips followed ravines which traverse the Public Cemetery in the Happy Valley. The bridges and part of the boundary wall were destroyed, the bed of the nullah was choked, and about 5,000 cubic yards of sand were carried through the Cemetery and deposited on the Race Course below, (at P. on plan) but fortunately not a single grave was in any way injured or disturbed.
32. The great Reservoir at Tytam, and the works connected therewith suffered no serious injury. The toe of the slope of the overflow weir, and some of the earth slopes below the concrete dam were washed away. It is satisfactory to be able to record that the manner in which the Tytam Water- works generally (ie. the great reservoir, the aqueduct, and the service tank and filter beds), have stood the severe test to which they have been subjected speaks well for the quality of the material and work manship, and for the care bestowed on their construction.
33. It will thus be seen that of the three grave cases of damage resulting from the storm, in two instances viz.: (1) the Albany or Military Nullahi (including the Tytam service tank) and (2) the Glencaly Nullah and culvert, the cause of the accidents may be traced, in part at least, to the opera tions of man, while on the other hand the great landslips along the line of the Tytan aqueduct above the Happy Valley, were entirely due to natural causes.
Damage to roads and other works outside the City and at Kowloon.
34. As already stated there was hardly a road or street in the Colony that did not suffer more or less. Landslips occurred in numerous cases, and many were on a considerable scale. bridges were also either damaged or destroyed. For full details respecting these injuries I beg to Some small refer
you to Mr. CorPER's report dated 26th ultimo (Appendix 19.)
35. To give some idea of the extent and number of the landslips throughout the Colony, I may cite as an illustration the view which presented itself from the house in which I was staying as the storm cleared on the morning of the 30th May. The view embraces the mountain side from the Victoria Gap to East Point, and may include a superficial area of from two to three square miles. The hill slopes which before the storm were covered with verdure, were now scurred in all directions by land lips. Of these I counted about thirty, and since others on the area indicated are concealed by the valleys, and the folds of the hills, it is probably considerably under the mark to estimate the nuni- ber of slips in this locality at fifty. Assuming the same proportion over other parts of the Colony we should have a total of some hundreds varying in mass from a few tons to several thousands.
Operations for repair of damage.
36. Immediately after the storm arrangements were made for repairing the damage, especial re- gard being had to the relative importance of the localities concerned.
37. Temporary works to allow of the supply of the Tytan water to the town, which had been entirely cut off by the effects of the atorm, were at once commenced, and completed in a few days, and the repairs to the aqueduct have since been pushed on, and are now approaching completion.
38. The repairs to the Tytani service tank and filter beds are progressing favourably. The prin- cipal obstructions in the streets and roads caused by landslips and debris brought down by torrents I have been removed, and the repairs to the culverts, especially that of the Glenealy Nullah, are being pushed forward; although the progress made has not been so great as it would otherwise have been, owing to frequent interruptions from the flooding of the work.
39. The following is a summary of the estimated cost of repairs to Goverument property caused by the late storm. The detailed estimates prepared by Mr. Cooper and Lieutenant-Colonel CHAMPER- NOWNE, R.E. are given in the Appendices D and E.
ESTIMATE OF STORM DAMAGE.
Aqueduct and Bowen Road, Service tank and filter beds, Tytam Reservoir,
Tytam Water-works.
Watermains and subsidary works,.
City of Victoria.
Cemetery and Race Course, Bowrington Bridge,, Removing landslips and repairs Eastern District, - Albany Nullah and Queen's Road adjoining same, Do. work done by Military,
$ 7,300
27,000
5,000
2,700
$42,000
Į
$ 1,465
1,300
1,956
7,040
384
Glenealy Nullab and streets adjoining,.......... Removing landslips and repairs to Western District, Minor repairs to roads, -
18.107
4,884
2,000
$37,136
Roads throughout the Island outside the City, Ronds und Streets, Kowloon,
13,050
1,800
$93,986
Contingencies 20 per cent.,.
18,797
$112,783
Total...
40. Although the damage caused by the late storin is very considerable, there is I think cause for satisfaction that no graver results followed, and that the community was spared from greater calamity to life and property.
Of the injuries to private property I have not sufficient data to form an estimate, but it may I think be safely assumed that (as is usual in similar cases) the popular estimates formed under first impressions will prove, on investigation, to have been exaggerated.
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