The answer because it must make its way
through tiny pore spaces. A speed of 1 foot per day or larger is
a high rate of movement for ground water,
and ground-water speeds can be as low as 1 foot per year or 1 foot
per decade. In contradiction, velocities of streamflow usually are calculated
in feet per second. A speed of 1 foot per second is equivalent round 16 miles
per day.
