Riddle

1. I fall from pinnacles that are perhaps reachable,
Plopping against the surface; sometimes silent, sometimes violent.
I can clean entire cities with my careful cover,
Or destroy entire districts with a trouble-free drift.
Some take pleasure in my presence and even anguish in my absence
Entire communities depend on my charity.
I am the cup-filler and the wet-leak,
That foster fields and feed the flowing-blue-stallions.

2. Inevitable at every instant;
People typically have trouble with me,
I am either protracted, or go by too promptly.
I determine when everything starts and everything ends.
I am the steady thitherto, the constant course span,
Ticking-by-day, never ending, never stopping, and never waiting.