The Temple Waters
"On that day His feet shall stand on The Mount Of Olives which lies before Jerusalem on the east; and the Mount of Olives shall be split in two [see Earthquake!] from east to west by a very wide valley; so that one half of the Mount shall withdraw northward, and the other half southward ... On that day living waters shall flow out from Jerusalem, half of them to the eastern sea [i.e. the Dead Sea, or The Salt Sea] and half of them to the western sea [i.e. The Mediterranean Sea]; it shall continue in summer as in winter. And The Lord will become King over all the earth; on that day The Lord will be one and His Name one." (Zechariah 14:4,8-9 RSV)
"Whoever drinks of the water that I shall give him will never thirst"
Water is vital to physical life, so water is an apt metaphor for the Holy Spirit of God which is vital to eternal life.
"Jesus said to her, "Every one who drinks of this water will thirst again, but whoever drinks of the water that I shall give him will never thirst; the water that I shall give him will become in him a spring of water welling up to eternal life." (John 4:13-14 RSV)
"On the last day of the Feast, the great day [i.e. the 8th day of the Feast Of Tabernacles - see Christ's Feast of Tabernacles and Christ's Eighth Day], Jesus stood up and proclaimed, "If any one thirst, let him come to Me and drink. He who believes in Me, as the Scripture has said, 'Out of his heart shall flow rivers of living water.'" Now this he said about the Spirit, which those who believed in Him were to receive; for as yet the Spirit had not been given, because Jesus was not yet glorified." (John 7:37-39 RSV)
Nevertheless, because there will still be physical humans on earth after Christ's return (see the Fact Finder question below), physical living waters will also flow from Christ's throne.
"Then he brought me back to the door of the temple; and behold, water was issuing from below the threshold of the temple toward the east, for the temple faced east [see Why Did They Face East?]; and the water was flowing down from below the south end of the threshold of the temple, south of the altar. Then he brought me out by way of the north gate, and led me round on the outside to the outer gate, that faces toward the east; and the water was coming out on the south side.
Going on eastward with a line in his hand, the man measured a thousand cubits, and then led me through the water; and it was ankle-deep. Again he measured a thousand, and led me through the water; and it was knee-deep. Again he measured a thousand, and led me through the water; and it was up to the loins. Again he measured a thousand, and it was a river that I could not pass through, for the water had risen; it was deep enough to swim in, a river that could not be passed through. And he said to me, "Son of man, have you seen this?"
Then he led me back along the bank of the river. As I went back, I saw upon the bank of the river very many trees on the one side and on the other. And he said to me, "This water flows toward the eastern region and goes down into the Arabah; and when it enters the stagnant waters of the sea, the water will become fresh. And wherever the river goes every living creature which swarms will live, and there will be very many fish; for this water goes there, that the waters of the sea may become fresh; so everything will live where the river goes. Fishermen will stand beside the sea; from Engedi to Eneglaim it will be a place for the spreading of nets; its fish will be of very many kinds, like the fish of the Great Sea. But its swamps and marshes will not become fresh; they are to be left for salt. And on the banks, on both sides of the river, there will grow all kinds of trees for food. Their leaves will not wither nor their fruit fail, but they will bear fresh fruit every month, because the water for them flows from the sanctuary. Their fruit will be for food, and their leaves for healing." (Ezekiel 47:1-12 RSV)
Fact Finder: Why will there still be physical people on earth after Christ's return?
See When Will You Be Judged?