CO129-526-10 Water supply- Shing Mun Valley Scheme with plans of the dam and reservoir sites 8-5-1930 - 10-9-1930 — Page 152

- 5 -

189

Dam C.C.

Dam D.D.

I estimate it would cost $4,700,000 to construct or at the rate of $2,350 per million gallons.

Dam on Line C.C. slightly above Dam B.B. would have a maximum depth of water of 190 ft. a maximum depth to bottom of foundations of 245 feet and impound approximately 2,000 million gallons. I estimate it would cost $4,400,000 to construct or at the rate of $2,200 per million gallons.

Dam on Line D.D. is slightly above Dam C.C. and is just outside the gorge. This dam would have a maximum depth of water of 182 feet have a maximum depth to bottom of

foundations of 220 feet and would impound a little less than

2,000 million gallons. I estimate the cost of construction

would be $4,550,000 or at the rate of $2,275 per million

gallons.

As the level of Pine Apple Pass is 542 A.O.D. I

have included in the above estimates $250,000 which I

estimate as the cost of the necessary dam at that point.

It would appear from the above figures that it

would be much cheaper to eliminate the Village Dam Reservoir

and raise the Gorge Dam to a Top Water level of about 600

A.O.D. and thus secure the 2,000 million gallons storage in

one reservoir.

With storage of 2,000 million gallons and taking

the direct drainage Area only, a supply of 64 million gallons

per day would be ensured throughout the driest known period.

As the existing temporary intake works produce approximately

2 million gallons per day, this would mean an addition of

approximately 4 million gallons of gravity water per day to

the Colony's supply.

Of the three Dam Sites discussed above, from the

information now available I would favour the Site on Line

D.D., although this does not work out the cheapest Dam.

Dam