into Town; this volume to be increased by the Storage Works in question at some future date when the Colony allows of it.
It is therefore now proposed to erect across the Valley, at the site of what was to have been dam, the high Embankment, a dwarf masonry wall in order to form a settling Pond whence to draw off the contents of the stream into the Conduit tunnel.
Before entering the latter, the water will be passed through a small quage basin furnished with a proper guage, as also with an overflow for the escape of surplus waters.
The Conduit Tunnel will be 2445 Yards in length having an internal diameter of 6 feet and is designed to act as a service tank.
Almost the entire portion will be driven through the solid granite. Where this is the case the heading will be simply cut and dressed off to the dimensions and section of the tunnel, no lining being necessary; should fissures be found they will be carefully stopped off with Cement, but springs of water if met with will be left open and utilized.
The tunnel will have a fall from its Inlet to its outlet of 4 in 2000, and at the latter the water will be received into another small guage basin in order to ascertain whether its volume has increased or diminished in its passage through.
After passing through the Guage the water enters the Conduit, which will be 2 feet wide by 2 feet deep in Cross section. The Conduit is 1356 yards long, and extends to a point shown on the plan where it will join the 18 inch iron main which forms the Syphon between the Conduit end and the service tank in Town, a distance of 600 Yards.
Between the Tunnel Outlet and the Syphon head there is a difference of level of 52 feet 6 inches and the Conduit will therefore have a uniform fall from one end to the other, the gradient being 1 in 68.
Any available hill side feeders will be caught into the Conduit in the manner already suggested by Mr. Rawlinson in his Sketchs prepared last year, and the Conduit will be provided with suitable...
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