4 
There is, however, only a distance of 1^ miles between a 
bend of the creek and the Enoggera Reservoir, and tbe ridge is 
very abrupt, with a height of 190 feet above the Reservoir. 
About 20 chains of tunnel and 3 miles of pipe would be sufficient 
to convey water from the upper part of the north branch of 
Moggill Creek into the Enoggera Reservoir. 
The watershed of the north branch of Moggill Creek, which 
would be available for a reservoir, is about 3,000 acres, while 
there is every facility for constructing the necessary works for 
storage. 
In carrying out this work it is proposed to commence at 
the Enoggera Reservoir, and make a cutting in the slate rock for 
20 chains, when it would reach a depth of about 30 feet ; then 
to tunnel through the ridge separating Enoggera Creek from 
Moggill Creek a distance of 20 chains, and a second cutting of 
10 chains, all having a rising grade of 10 feet per mile ; arid that 
for this total distance of 50 chains the water would flow in an 
open conduit, as the rock is sufficiently hard without lining with 
masonry, and thus the expense of more than half a mile of iron 
pipes would be avoided. 
From this open conduit iron pipes would be laid down the 
ravine 50 chains to the north branch of Moggill Creek, and then 
up that valley about 150 chains to a point where the channel of 
the creek is about 25 feet above the surface of the Enoggera 
Reservoir, and there is a narrow gorge suitable for the con- 
struction of a dam, which, if made 80 feet high, would back up 
the water in the valley for about one mile, with a probable 
storage capacity of seven hundred millions of gallons. 
The valley being narrower than that of Enoggera at the 
Reservoir, it would not be more costly to build a dam of 80 feet 
than that of 60 feet at Enoggera ; and it is important both in 
regard to evaporation and freedom from weeds to secure the 
greatest available depth of water in storage reservoirs. 
From the dam to the open conduit, a pipe nine inches 
diameter, with a mean fall of ten feet per mile, would deliver 
400,000 gallons per diem, and as the additional head of water in 
the Reservoir would generally double the pressure, the pipe 
would deliver 600,000 gallons per diem. 
The passage through the 50 chains of open conduit would 
improve the water by contact with the air, besides saving the 
expense of cast-iron pipes. 
The most formidable item of this scheme is the tunnel 
between the Moggill and the Enoggera valleys, but as it would 
be only four chains longer than the principal tunnel already 
made on the line between Enoggera and Brisbane, and the rock 
cannot be of a harder description, the cost may be put at about 
£3,000, or £7 per yard forward. 
