82
With reference to paragraph (c) of my minute of 1st June, 1921, I find that out of tl 76 days when there is a velocity of less than 24 feet per second, there are 33 days when a velocity of 2.25 per second or more corresponding to a tidal range of 3 feet or more, is obtained.
I would however point out that a higher standard of efficiency can, if desired, be provided by increasing the diameters of the sewers and other minor alterations provided the main principles as laid down, are adopted.
Although this system of drainage has not been adopted or suggested elsewhere so far as I can ascertain from any book of reference or record of drainage works completed, I am confident of the success of any such scheme, where conditions are such as obtain in the Kowloon Peninsula, and, in view of the low cost of construction and upkeep and its efficiency compared with any other scheme, I strongly recommend its adoption.
6th June, 1921.
E. NEWHOUSE.
Annexes 11 to 17 inclusive submitted by Mr. L. Gibbs.
Annexe 11.
Cost of Providing Salt Water.
Peak Estimated cost of works to pump 15,000 gallons a day $182,000 at 7% $12,740 a year.
15,000 gallons a day- 5,475,000 gallons a year.
12,740
5,475 add
$2.33
1:00 pumping
→
$3.33 per 1,000 gallons.
Middle Levels.-Estimated cost of works to pump 60,000 gallons a day $235,000 at
$16,450 a year.
7%
60,000 gallons a day
=
21,900,000 a year.
1,645,000
0.75
21,900
add
0.50 pumping
$1.25 per 1,000 gallons.
Kowloon Point.-Estimated cost of works to pump 280,000 gallons a day $227,000 at 7% $15,890 a year.
280,000 gallons a day
102,200,000 a year.
1,589,000
0.16
102,200
add
0.20 pumping
$0.36 per 1,000 gallons.
L. GIBBS.
30th May, 1921.