CO129-204 - Acting Governor Marsh - 1882 [11-12] — Page 379

details of the bye-wash works

best designed

may

374

however be

may on the spot after the ground has been opened out and the actual position of the underlying rock ascertumed. The sell the overflow weir be placed at a lovel of four feet below the level of the dam. The foundations should be carried down to - the rock... Near the Weir the rock floor of the bye-wash

roughly quarried into steps to leaven the velocity of the everflow-

and at intervals of eight or ten feet dwarf

may be

grande piers may

be erected

of the Weir with vertical

grooves cut down

along

the top

on

edge from

the

water and

their sides to admit of stop planks, four

inches thick, being inserted

pier to peer to love

up

may

be

raise the top level of the reservoir by another 24 inches - These planks lowered into place towards the end of rainy season when there is no further likelihood of freshets and their joints may be made watertight by caulking.

The

27. Concluding remarks While the excavations for the foundations in the bottom or cenke of the Gorge are. being proceeded with, the ground may be kept day by passing the whole of the Tylam sheam through a line of iron -pipes laid temporarily from a small provisional dam above Stream When the concrete Substructure is being erected a

Ꮴ

I shaped gap may be left in the centre for the passage of the waters, and the work around the Valve well and Cubirt may be pushed on with until the whole of the surrounding mas barch, When the inlet and outlet Culverts

to the height of a few feet above

the crown of the

are

: completed the V shaped gap.

73.

in the dam