Lot's of Freshwater, But NOT WHERE It's Needed

Precipitation, commonly called rain, the predominant source of freshwater, is more than enough for a 10+ billion human population plus the other species and nature's ecosystems that must have freshwater.
Rainfall

Source - countryofsb.org

From the very beginning, rain has supplied the freshwater needs of human, other species and nature's ecosystems in two ways: 
- Either, by dropping manna-from-the-heavens directly onto crops and where the freshwater was needed and/or 
- Replenishing lakes and other bodies tapped by humans, other freshwater species and nature's freshwater ecosystems.
Total Rainfall on land

Source - sciencemag.org

A total of 98,500 cubic kilometers of rain is estimated to fall on land every year.
This liquid precipitation is in addition to the 12,500 cubic kilometers that fall as ice and snow on land.
Ignoring for a minute that this rainfall in not geographically uniform and that it has extreme spacial and temporal variations, the 98,500 cubic kilometers/year
= 270 cubic kilometers/day
As 1 cubic kilometer = 264 billion US gallons,
the average rainfall of 270 cubic kilometers/day
= 71,280 billion US gallons/day
For a 10 billion human population (the projected human population in 2050), this rainfall
= 7,128 US gallons per day.
Why Freshwater Scarcity?
Ignoring freshwater accessed over long distances from surface bodies (lakes, rivers, etc) and underground aquifers, with so much rainfall available per person per day, why do we have scarcity anywhere in the world?
The answer: Scarcity is the result of rainfall not being uniform all over Earth's land mass and the unpredictable spacial and temporal variations of rainfall.