Greetings in the benevolent name of our Lord and Savior Jesus the Christ, after reviewing some of the responses, I am compelled to share a thought of wisdom. Truth as you know it is not always truth! Kids beleive there is a santa clause to this very day because of a lie that was implanted as a seed in their conscience, further some believed in the boogie man and other susperstitious idioms or beliefs.
The Word of God is Truth, that is fixed, the Word of God as we believe it may be truth as we know it but not truth according to the Word of God. This is why Sunday School and Bible class is very important to the Development of your Spiritual Life.
The phrase "open the floodgates to heaven" can be allegorical or metaphorical, and just because it is not specifically phrase that way in the Bible, does not render this phrase illegitament. If I choose to use this metaphoric vernacular, it is my expression or my request to my Father to do something that's already promised in His Word!
If what's behind the gate is what I want, and it's is not denied to me in His Word, then aske according to His Word I beleive His Word said, "ask the Father what you desirel, in His name, that your joy may be full." So my request to "open the floodgates of heaven" means Lord I have been obedient to your Word, and you told me to prove you now herewtih, so I request that the "floodgates of heaven be opened" because I act according to your Word and now I'm asking according to your word, and by Faith in your Word I shall receive it, because I'm entitled to it because of your word. Maybe before I wasn't entitled because I didn't act according to your word and as a result I could not recieve the promises, that you promise because I failed to do what was required to get the benefit or promise that I desired.
So I must agree with Sister T, don't take a dogmatic approach to the word, it's your way or the highway, rather it's God way and that's all to it. The Bible wasn't written in English, nor did anyone at that time speak English, it would be foolish of us to hold the English version in strict compliance since it is a traslation of the Vulgate, which is a translation. Use your word study and do some research of the Hebrew language and the Greek and then act according to 2 Timothy 2:15:)
Have a Blessed Day,
Robert S. Ellington-Snipes