Most canyons are formed by flowing rivers through erosion over long periods of time.
Rivers, rainwater, well water and most lakes contain fresh water.
Canyons are formed by rainwater.
What are canyons formed by?

(1) clouds
(2) stars
(3) erosion
(4) loose soil
(5) wind
(6) ice wedging
(7) rainwater
(8) calcite