Water is everywhere in The Lion King—everywhere that there's life, at least.
Allow us to explain. Water and water-specific imagery show up in places that are safe and nurturing. For instance, there's the watering hole and winding rivers in the Pride Lands and the giant lake in front of Timon and Pumbaa's jungle mountain.
As Simba is falling in love with Nala, the two of them romp around in a mini-waterfall. All of these places tend to be positively connoted with love, safety, and security.
Where there isn't water, however, there's bound to be evil or danger. Simba and Nala wander into the bone-dry elephant graveyard and nearly get eaten by a pack of hyenas. Scar plans all of his evil plots in the very same elephant graveyard, where green lava flows everywhere. Simba nearly dies in a waterless desert. The absence of water means our characters are in trouble.