For example, the toilets use only one gallon of water that is pumped by hand into raised tanks and flushed only when necessary.
(the toilets; use; only one gallon of water that is pumped by hand into raised tanks and flushed only) (only one gallon of water; is pumped; by hand; into raised tanks) (only one gallon of water; flushed only; T:when necessary)
the toilets only one gallon of water only one gallon of water
use is pumped flushed only
only one gallon of water that is pumped by hand into raised tanks and flushed only
by hand into raised tanks
T:when necessary