CO129-117 - Public Offices - 1866 — Page 177

to prevent any pressure, washing,

or wasting of the base of the Bank.

Concrete is shown beneath the

base of the Bank

on both sides of the paddle wall. I do not

however see drains indicated

beneath the outer half of the seat of the Bank.

The concrete to receive

puddle wall should not have

a level surface,

but be cross-hatched as under

Bank. Outside Puddle Wall

Bank Inside Drainage

surface Ground

Concrete

The material on

both sides of the puddle wall should be water tight

for 30 feet in width at the least.

This material should be the best

and firmest of the subsoil, specially selected, and be carried up with the puddle wall in thin layers. If walked and trampled during the process of formation,

the embankment will be better consolidated.

The outlet culvert should be

tunnel or made

in solid rock or

of drift-way

and of the ground proposed.

on one side,

proposed. 25 feet above the bottom of the

Reservoir, it may be used as a

water escape during

the progress of the works, and to advantage during flood.

Cross Section of Puddle trench

The Culvert.

This Culvert may be lined