A toilet that uses less water than a standard one during flushing, for the
purpose of conserving water resources. The units are about the same size
as older designs but use about half the water – 1.6 gallons instead
of 3.5 gallons per flush – and consequently have less flushing power.
Replacing conventional toilets with low-flow models has the potential to
save up to 12,000 gallons a year in a typical household. However, the benefits
can be offset by the need to flush more than once to remove solid wastes,
and by difficulties caused by stoppages and overflows. These problems of
low-flush have been largely fixed by manufacturers modifying the passageways
to move a reduced amount of water more vigorously into the bowl.