Ways to get enough water to use Shape the Flowing River

[Aquillion]

Shape the Flowing River is one of the few good (and efficiently-costed) Four Elements Monk abilities:


As an action, you can spend 1 ki point to choose an area of ice or water no larger than 30 feet on a side within 120 feet of you. You can change water to ice within the area and vice versa, and you can reshape ice in the area in any manner you choose. You can raise or lower the ice's elevation, create or fill in a trench, erect or flatten a wall, or form a pillar. The extent of any such changes can't exceed half the area's largest dimension. For example, if you affect a 30-foot square, you can create a pillar up to 15 feet high, raise or lower the square's elevation by up to 15 feet, dig a trench up to 15 feet deep, and so on. You can't shape the ice to trap or injure a creature in the area.

Per Sage Advice answers, anything you shape lasts indefinitely (https://www.sageadvice.eu/2016/01/30/does-shape-the-flowing-water-last-for-the-action-only/), and "can't trap" just means you can't directly affect a creature - you can still surround them with walls or a cage made of ice as long as you don't try to eg. freeze their ankles in ice directly.

But of course the ability has one massive drawback - to use it, you need lots of water in the area (ideally at least 30 feet long in one dimension to maximize what you can create.)

What options are available to get lots of water onto the battlefield quickly? Ideally, at minimal cost and capable of working indoors?

[Unoriginal]

Carry a huge jar filled with water?

[Degwerks]

Decanter of Endless Water an uncommon magic item

[Unoriginal]

Decanter of Endless Water an uncommon magic item

Good idea.

[Aquillion]

If you can get your DM to guarantee that you'll get your hands on one early, that sounds like an actually fun build. One ki point to shape ad-hoc semi-permanent walls of ice in whatever shape the party needs is a pretty good deal.

That said, even at geyser level, it's only 30 gallons (about one medium-sized barrel's worth) - that's enough to cover the floor, but not very deeply. I suspect many DMs would limit what you can shape with that much water.

You could produce more water if you have time to prepare the battlefield, of course... now I'm picturing a monk who insists on spending a half-hour flooding each dungeon from the outside with the decanter before entering.

(I feel that one thing the subclass would really benefit from is similar "shaping" abilities for the other three elements - the creativity and potential power that Shape the Flowing River offers at a low cost is probably the sort of AtLA bending stuff people want out of the class.)

[Desteplo]

You can go the classic, two buckets suspended on a long pole over the shoulder. That’s like 6 gallons easy.

Most monks don’t have much to carry anyway

If you have a cart, you can carry around a barrel or two. You’ll need to refill water skins anyway so double purpose

[JackPhoenix]

You can go the classic, two buckets suspended on a long pole over the shoulder. That’s like 6 gallons easy.

Most monks don’t have much to carry anyway

If you have a cart, you can carry around a barrel or two. You’ll need to refill water skins anyway so double purpose

It's less impressive when you realize 6 gallons of water is less than one cubic foot. Even with 40 gallon barrel full of water, you only have a little over 6 cubic feet to work with. One 5' space on the map has a volume of 125 cubic feet.

Those 40 gallons of water also weights 400 pounds on top of the 70 pounds for the barrel itself, and you'd need to get it to where the fight happens somehow, it's useless on a wagon parked in front of the dungeon. Good luck with that. Even those two buckets are over 60 pounds.

Conclusion: water is heavy and (after having to do the math) imperial units are stupid.

[Aquillion]

Yeah, it's a shame. I guess it's a talk-to-your DM thing. Shape the Flowing River is so good as long as the entire campaign takes place in a swamp or tundra, though.