Arrange the sentences P, Q, R, S and T in the correct order to form a meaningful paragraph.

P: The water is then led through a filter of sand and gravel into a pit.
Q: Rainwater falling on a roof is first collected in gutters along its edges.
R: From the gutters, pipes carry it down to the ground.
S: Over a few years, this raises the level of water in nearby wells.
T: In the pit, it slowly soaks into the soil instead of running off into the drains.