Without the full context, it will be somewhat difficult for the ordinary person attending Mass to grasp the point of the first reading. We may, however, take a hint from the responsorial Psalm and meditate on the theme of water as the prophet Elijah prayed for rain.
The Psalm is essentially a meditation, reciting the different ways and places in which God gives us rain to water the earth and the different life-giving effects of this essential gift. Such a recitation is a form of the prayer of thanksgiving.
Concern for the ecological well-being of our Earth has had the good effect of making us more conscious of our use of water and more sensitive to the waste of water that not infrequently accompanies our life's activities.
Scarcity of water and the manipulation and monopolising of water sources leads to political tension and even threatens war. As far as we can, we must be conscientious in our use of this precious gift of water and of the life it fosters.
Father in heaven, as stewards of your creation, we thank you and praise you for the gift of life and for the gift of all the elements which sustain life. By your grace make us always consciously and joyfully responsible for the proper use of your gifts.