BRIDGE AND NOTCH FALL.
In this case the usual practice of placing the bridge downstream of the fall has not been followed.
The gauge well is seen on the left bank.
To face p. 87.
For cisterns below falls the usual rule for the depth is
K = H + ∛H √D
where H is the depth of water in the upstream reach, and D is the difference between the upstream and downstream water levels. Another rule for distributaries is
K = H + D3
the length of the cistern being 3 H and its width the bed width of the channel.