28 
BULLETIN 1408, IT. S. DEPARTMENT OF AGRICULTURE 
lift should be kept as 
low as possible, how- 
ever, this often requir- 
ing the walls of the 
structure to be de- 
signed to prevent the 
entrance of water. A 
plant in operation on 
the Sacramento River 
was designed to 
withstand a head of 
water 20 feet above 
the floor, with walls 
and floor several feet 
thick to prevent float- 
ing. 
The suction bay 
must have a greater 
depth than the main 
canal and a sufficient 
area to permit move- 
ment of the water to 
the intake pipes at low 
velocities. A screen 
must be provided to 
protect the intake. If 
the suction bay is not 
an integral part of 
the concrete house or 
foundation, its sides 
must be well protect- 
ed with sheet piling: 
and in case sand boils 
develop, the sides and 
bottom must be made 
of reinforced concrete 
designed to withstand 
upward pressure. In 
fixing the elevation of 
the floor, allowance 
should be made for 
subsidence where 
muck or peat soils 
exist. 
Where the discharge 
pipe passes through 
the levee, extreme 
care must be taken 
to prevent seepage by 
construction of cut- 
off walls. The dis- 
charge bay, made of 
reinforced concrete, should be substantially protected against wash- 
ing and undermining, with elevation such that the outlet pipes will 
Grout in above 
this line after 
pump and motor 
are set 
^l8"Well casing 
SECTION ON CENTER LINE 
Fig. 
18. — Pump house for drainage wells, Salt Riv er Valley, 
Ariz. 
