Hills covered with tropical forest on Boracay island need watering

Islands with low elevation have less water resources for the many months of dry season. To keep the island green year round lots of rain is needed to saturate the soil with water.
In another few months - by October/November the next dry season comes for sure and usually zero rain during dry season or if rain then only little rain just enough to give a beauty shower to all leaves and plants and clean all nature from dust and dirt.