How many times is "water" mentioned in the Bible and how significant is it?

I have run the references to water (or derivatives of it) in scripture and come up with 722.  The significance of water in scripture is a huge question, and one that will take up more space than I have here. Perhaps I can give you just a few thoughts that will wet your appetite for further study.

The first mention of water in scripture is found in Genesis 1:2And the earth was without form, and void; and darkness was upon the face of the deep. And the Spirit of God moved upon the face of the waters.
See All... and the last mention is found in Revelation 22:17And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.
See All.... In between those two books water flows right through the pages of scripture. This should teach is that there is a great spiritual significance to it.

Water speaks of physical (or natural) birth

In Genesis 1:20And God said, Let the waters bring forth abundantly the moving creature that hath life, and fowl that may fly above the earth in the open firmament of heaven.
See All..., we read of the first mention of life, and this life comes from water, "...Let the waters bring forth abundantly the moving creature that hath life...". This thought is again repeated in the New Testament in John 3 when Nicodemus, a ruler of the Jews is asking questions of Jesus. In verse 5 we read, "Except a man be born of water and of the Spirit, he cannot enter into the kingdom of God." Notice here, the water birth (physical) comes before the Spirit birth (spiritual). We see the reality of this when a woman is in labour and the baby is about to be born. We wait for the 'waters to break' which surround the baby until birth. We cannot be spiritually re-born until we have first been naturally born.

Water speaks to us of the word of God

In Ephesians 5:26That he might sanctify and cleanse it with the washing of water by the word,
See All..., concerning the church we read, "That he might sanctify and cleanse it with the washing of water by the word." The Psalmist in Psalm 119:9Wherewithal shall a young man cleanse his way? by taking heed thereto according to thy word.
See All... writes "Wherewithal shall a young man cleanse his way? by taking heed thereto according to thy word." Reading the Bible has a cleansing effect on the reader. Christians would do well to sit and read, study and meditate together on the word of God. In the Tabernacle in the Old Testament, we read in Exodus 30:18Thou shalt also make a laver of brass, and his foot also of brass, to wash withal: and thou shalt put it between the tabernacle of the congregation and the altar, and thou shalt put water therein.
See All... that Moses was to make a laver of brass and put water in it. This was to be situated between the Tabernacle and the altar. The priests were to wash their hands and feet in this when they went into the Tabernacle "that they die not". They needed to purified. The Lord was telling them that they constantly needed to have their feet cleaned. We see a picture of this in John 13. The Lord Jesus washes the disciples feet. They were already washed, but needed their feet washing.

Consider the words of verses 9-10 "Simon Peter saith unto him, Lord, not my feet only, but also my hands and my head. Jesus saith to him, He that is washed needeth not save to wash his feet, but is clean every whit: and ye are clean, but not all."

Note that Lord (v14) then tells the disciples that they ought also to wash each others feet, "If I then, your Lord and Master, have washed your feet; ye also ought to wash one another's feet." It seems to me that this is a future instruction, as at this point their feet were clean. Surely, spiritually speaking, we wash each others feet through reading the word of God. That's why the Lord said in John 15:3Now ye are clean through the word which I have spoken unto you.
See All... "Now ye are clean through the word which I have spoken to you." In the Christian life, we all need to be purified from the filth of this world, we all need our feet cleaned.

Water speaks to us of the purification of the Christian

This is really linked to the previous consideration, but the following verses are interesting to ponder on. Concerning the nation of Israel in a future day, the following words are recorded in Ezekiel 36:25Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you.
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Ezekiel 36:25Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you.
See All... Then will I sprinkle clean water upon you, and ye shall be clean: from all your filthiness, and from all your idols, will I cleanse you.

This is a promise from God for a time when Israel returns to Him (see vs 24-38). However, there is also clearly an application here for the sinner who comes to Christ when we compare this verse with Hebrews 10:22Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
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Hebrews 10:22Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
See All... Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.

Water speaks to us of spiritual life

In Genesis 2 we read of the perfect conditions of the garden of Eden. This garden was watered by a river (v10). Without water, the garden would have died, as plants, animals and humans cannot survive without water. It seems to me that this river is a beautiful picture of the life that Christ gives to His children through the Spirit of God. Consider the following verses that speak of this:

Exodus 17:6Behold, I will stand before thee there upon the rock in Horeb; and thou shalt smite the rock, and there shall come water out of it, that the people may drink. And Moses did so in the sight of the elders of Israel.
See All... Behold, I will stand before thee there upon the rock in Horeb; and thou shalt smite the rock, and there shall come water out of it, that the people may drink. And Moses do so in the sight of the elders of Israel.

Isaiah 12:2-3 [2] Behold, God is my salvation; I will trust, and not be afraid: for the LORD JEHOVAH is my strength and my song; he also is become my salvation. [3] Therefore with joy shall ye draw water out of the wells of salvation.
See All... Behold, God is my salvation; I will trust, and not be afraid: for the LORD JEHOVAH is my strength and my song; he also is become my salvation. Therefore with joy shall ye draw water out of the wells of salvation.

Isaiah 55:1Ho, every one that thirsteth, come ye to the waters, and he that hath no money; come ye, buy, and eat; yea, come, buy wine and milk without money and without price.
See All... HO, every one that thirsteth, come ye to the waters, and he that hath no money; come ye, buy, and eat; yea, come, buy wine and milk without money and without price.

Jeremiah 2:13For 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.
See All... 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.

John 4:14But 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.
See All... 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.

John 7:38-39 [38] He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. [39] (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)
See All... He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water. (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given: because that Jesus was not yet glorified.)

This water   is the everlasting life that we enjoy now in Christ. That's why the scripture says in 1 John 5:12He that hath the Son hath life; and he that hath not the Son of God hath not life.
See All... "He that hath the Son hath life; and he that hath not the Son of God hath not life." Without water there cannot be life: Without the Lord Jesus Christ there cannot be eternal life. It's interesting to me that the greatest expanse of water in the world today is the sea. The sea in scripture is a fascinating subject, and one we can't go into here. However, I would encourage you to look at the references and you will see that the sea often speaks to us of restlessness and tribulation (See Matthew 14:22-33 [22] And straightway Jesus constrained his disciples to get into a ship, and to go before him unto the other side, while he sent the multitudes away. [23] And when he had sent the multitudes away, he went up into a mountain apart to pray: and when the evening was come, he was there alone. [24] But the ship was now in the midst of the sea, tossed with waves: for the wind was contrary. [25] And in the fourth watch of the night Jesus went unto them, walking on the sea. [26] And when the disciples saw him walking on the sea, they were troubled, saying, It is a spirit; and they cried out for fear. [27] But straightway Jesus spake unto them, saying, Be of good cheer; it is I; be not afraid. [28] And Peter answered him and said, Lord, if it be thou, bid me come unto thee on the water. [29] And he said, Come. And when Peter was come down out of the ship, he walked on the water, to go to Jesus. [30] But when he saw the wind boisterous, he was afraid; and beginning to sink, he cried, saying, Lord, save me. [31] And immediately Jesus stretched forth his hand, and caught him, and said unto him, O thou of little faith, wherefore didst thou doubt? [32] And when they were come into the ship, the wind ceased. [33] Then they that were in the ship came and worshipped him, saying, Of a truth thou art the Son of God.
See All..., Mark 6:47-52 [47] And when even was come, the ship was in the midst of the sea, and he alone on the land. [48] And he saw them toiling in rowing; for the wind was contrary unto them: and about the fourth watch of the night he cometh unto them, walking upon the sea, and would have passed by them. [49] But when they saw him walking upon the sea, they supposed it had been a spirit, and cried out: [50] For they all saw him, and were troubled. And immediately he talked with them, and saith unto them, Be of good cheer: it is I; be not afraid. [51] And he went up unto them into the ship; and the wind ceased: and they were sore amazed in themselves beyond measure, and wondered. [52] For they considered not the miracle of the loaves: for their heart was hardened.
See All..., John 6:15-21 [15] When Jesus therefore perceived that they would come and take him by force, to make him a king, he departed again into a mountain himself alone. [16] And when even was now come, his disciples went down unto the sea, [17] And entered into a ship, and went over the sea toward Capernaum. And it was now dark, and Jesus was not come to them. [18] And the sea arose by reason of a great wind that blew. [19] So when they had rowed about five and twenty or thirty furlongs, they see Jesus walking on the sea, and drawing nigh unto the ship: and they were afraid. [20] But he saith unto them, It is I; be not afraid. [21] Then they willingly received him into the ship: and immediately the ship was at the land whither they went.
See All...). Note, in all of these passages, the seas were calmed by the Lord Jesus. When we follow these thoughts through, we read those lovely words in Revelation 21:1And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea.
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Revelation 21:1And I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea.
See All... AND I saw a new heaven and a new earth: for the first heaven and the first earth were passed away; and there was no more sea."

No more sea in Heaven, no more restlesness, no more tribulation, all calmed by the Lord Jesus Christ forever. However, although there will be no more sea in Heaven, there will be water, eternal water that flows forever.

Revelation 22:1-2 [1] And he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb. [2] In the midst of the street of it, and on either side of the river, was there the tree of life, which bare twelve manner of fruits, and yielded her fruit every month: and the leaves of the tree were for the healing of the nations.
See All... AND he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb. In the midst of the street of it, and on either side of the river, was there the tree of life, which bare twelve manner of fruits, and yielded her fruit every month: and the leaves of the tree were  for the healing of the nations.

There may be other spiritual types for water that I haven't considered, but the above are the ones that spring to mind. I'll leave you with the final reference to water in the Bible found in Revelation 22:17And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.
See All...:

Revelation 21:17And he measured the wall thereof, an hundred and forty and four cubits, according to the measure of a man, that is, of the angel.
See All... And the Spirit and the bride say, Come. And let him that heareth say, Come. And let him that is athirst come. And whosoever will, let him take the water of life freely.