There is both a practical reason, and a spiritual comparison.
Practically speaking, it was most often the women who went to the wells of the area to draw water for household use, and sometimes to water the animals. So, if you hung around the wells you were likely to see most if not all of the women in that community.
God draws the comparison between water necessary for bodily and physical life to that necessary for spiritual life.
"My doctrine shall drop as the rain, my speech shall distil as the dew, as the small rain upon the tender herb, and as the showers upon the grass:" (Deu 32:2, KJV)
God's truth and doctrine was as the rain, and the Hebrews associated rain with His prophetic judgments. This surely is drawn for the most obvious association with the judgment that came upon all the earth / lands during Noah's flood, but is demonstrated in Micah 2:6 which reads in the English translation as:
"Prophesy ye not, say they to them that prophesy: they shall not prophesy to them, that they shall not take shame." (KJV)
but, according to Clarke's Commentary is literally:
"Do not cause it to rain; they will cause it to rain; they cannot make it rain sooner than this; confusion shall not depart from us." To rain, often means to preach, to prephesy; Ezekiel 20:46, Ezekiel 21:2; Amos 7:16; Deuteronomy 32:2; Job 29:22; Proverbs 5:3, etc." Source: here
Wells were sources of living water to sustain physical life. God's word is living water to the soul.
"For my people have committed two evils; they have forsaken me the fountain of living waters, and hewed them out cisterns, broken cisterns, that can hold no water." (Jer. 2:13, KJV)
"17 When the poor and needy seek water, and there is none, and their tongue faileth for thirst, I the Lord will hear them, I the God of Israel will not forsake them.
18 I will open rivers in high places, and fountains in the midst of the valleys: I will make the wilderness a pool of water, and the dry land springs of water." (Isa. 41, KJV)
The wife / lover in chap. 4 of Song of Solomon is compared to a fountain and a well of waters.
"12 A garden inclosed is my sister, my spouse; a spring shut up, a fountain sealed.
13 Thy plants are an orchard of pomegranates, with pleasant fruits; camphire, with spikenard,
14 Spikenard and saffron; calamus and cinnamon, with all trees of frankincense; myrrh and aloes, with all the chief spices:
15 A fountain of gardens, a well of living waters, and streams from Lebanon." (KJV)
And, in meeting the Samaritan woman at the well where she came to draw water, she met the Messiah, Yeshua through whom we have the spiritual life of the true living waters.
"10 Jesus answered and said unto her, If thou knewest the gift of God, and who it is that saith to thee, Give me to drink; thou wouldest have asked of him, and he would have given thee living water.
11 The woman saith unto him, Sir, thou hast nothing to draw with, and the well is deep: from whence then hast thou that living water? ...
14 But whosoever drinketh of the water that I shall give him shall never thirst; but the water that I shall give him shall be in him a well of water springing up into everlasting life." (KJV)
(Bold emphasis is mine.)