I'm a librarian running a Minecraft program where players will construct a city in a glass dome underwater. At the end of the program I want to flood the dome so they can see their city submerged. I can't quite get water to flood the area without going through and breaking each piece of glass. The best I've done is construct a flood gate with pistons on the top and sides of the dome to allow water to enter, but this does not fill the volume and stops after a block or two. Is there a more efficient way of doing this? Is there a mod? We run version 1.7.10.

  • 1
    Why are you in 1.7.10? That's almost 5 years old. Apr 10, 2019 at 22:43
  • Why can't they just build underwater? Survival or Creative? And do you want to fill the insides of the buildings, too? If not, what should define "inside" and "outside"? Does it have to be source water or can it be water flowing down? If it can be flowing water, you can just fill an area above it. Apr 10, 2019 at 22:44
  • We use 1.7.10 because we use Minecraft.edu, not to be confused with Educational Edition. That version never updated beyond 1.7.10. The players that come to the program tend to be very young (around 6 or so) and not very focused or adept at playing yet, so I need to design things to be as accessible as possible, and that means clearing the chamber of water first.
    – Serge
    Apr 11, 2019 at 13:44
  • Survival or Creative? And do you want to fill the insides of the buildings, too? If not, what should define "inside" and "outside"? Does it have to be source water or can it be water flowing down? Apr 11, 2019 at 14:05
  • Creative mode. If chambers are properly sealed they shouldn't flood. This is meant to test their building designs and demonstrate the challenge of building something like this. So ideally, water from the surrounding ocean would flow in and fill the open areas of the chamber.
    – Serge
    Apr 11, 2019 at 14:19

2 Answers 2


Making water fill an area the way you want (flowing into openings, but staying out of enclosed areas, etc.) is very difficult and would create a lot of lag when it gets applied. From your comments I figured out that just making the water first undetectable and then later detectable would solve your issue as well, you don't actually need the water to be gone at first. How do you make water undetectable? With a combination of a resource pack and a data pack.

This solution only works in Minecraft 1.13 and above. I don't know exactly why you are in 1.7.10, you have to figure out yourself whether you can upgrade. There's not really any way to do what I'm doing here in any way before 1.13.

First I created a resource pack with this layout:

    water_flow.png (a 32×32 completely transparent image)
    water_overlay.png (a 32×32 completely transparent image)
    water_still.png (a 32×32 completely transparent image)
    underwater.png (a 32×1024 completely transparent image)
pack.png (just a nice little image of a crossed out bucket)
pack.mcmeta with the content »{"pack":{"pack_format":4,"description":"Makes water undetectable, together with the data pack."}}«

*an empty sound file, downloadable here

I don't know if all of these are necessary, but it's always better to be safe.

Enabling this resource pack already does a lot for hiding water, but it still weakens light, makes the sky blue, reduces the view angle, lets you swim and so on. So there's additionally a data pack that removed these effects. To do that, it makes water not behave like water, by just overwriting the water.json tag with an empty list. This still changes the FOV inside water (due to the bug MC-147936) but it can be balanced by giving the player a speed 1 effect whenever they are inside water. This is done with a function. This function also gives everyone night vision so that they don't see the shadow of water. Due to another bug, this speed effect doesn't actually speed up flying players, so it should be fine. If not, everyone has to set their FOV wider manually in the game settings.

Here is the layout of the data pack:

   fov.mcfunction with the contents »effect give @a night_vision 11 0 true«(new line)»execute as @a at @s anchored eyes if block ~ ~ ~ minecraft:water run effect give @s speed 1 0 true«
    water.json with the contents »{"replace":true,"values":[]}«
    tick.json with the contents »{"values":["minecraft:fov"]}«
pack.mcmeta with the content »{"pack":{"pack_format":3,"description":"Makes water undetectable, together with the resource pack."}}«

What still happens with these two packs is that blocks like torches are flooded away by the water, but that would happen as soon as you add the water later anyway. Also, mobs can spawn and other effects of low light levels can still happen below water, but since this is a Creative building server, that hopefully shouldn't be too much of an issue.

How to apply:
The resource pack has to be linked in the server.properties file under the resource-pack option of a server, if it's running there, see here (archive). Otherwise it just goes into the usual resource pack location (archive) and has to be enabled from the resource pack menu.
The data pack goes into the usual data pack location (archive). Then enter /datapack enable "file/disable_water_data_pack" into the server console or into chat if you have command permissions. You might also have to do the same with /reload.
Here are zip files of the complete resource pack and data pack, both don't even have to be extracted, they already work as zip files.

  • I updated the datapack so that it now works without unpacking. Jun 14, 2019 at 19:25
  • Subtitles of water sounds still show this way, I will correct the resource pack one day. Jun 14, 2019 at 19:27
  • Actually, it seems like a lot of things are still not disabled with this: particles when entering and leaving water, general underwater particles, a bunch of sounds, a bunch of subtitles, … Not all of those are completely consistent either, for example a lot of subtitles are missing in Vanilla already. And the resource pack format has changed since I wrote this answer. So I will only update and complete if someone requests it. But I have at least updated the resource pack so that it actually works without unpacking. Dec 28, 2019 at 10:26


A) Install worldedit for 1.7.10

B) Do it manually. (Go into creative, get a water bucket and spam right click)

  • The bucket would work, but the kids wouldn't have the patience for it. I'll look into Worldedit. I've also been investigating Buildcraft's floodgates to this end. Thanks.
    – Serge
    Apr 11, 2019 at 13:46
  • If you're going to use worldedit, make sure to learn how to use it. Because sometimes people install worldedit on their servers and then they just mess the server up. youtu.be/SOOvommDpUA
    – Whitcheef
    Apr 13, 2019 at 9:11

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