Baldur’s Gate 3: How to Solve the Abandoned Cistern’s Water & Temple Valve Puzzle in BG3

The Sewers of Baldur’s Gate is full of filth, gnarly enemies, and, as it turns out, some puzzles. While exploring this region of Baldur’s Gate 3, players might run into the Abandoned Cistern’s Water and Temperature Valve puzzle.

To solve it, players must interact with the Water Level Valve and the Temperature Level Valve. Interacting with them will cause the water and temperature levels to increase, respectively. The goal of manipulating these valves is to open the vault door on the lower floor and possibly access a load of goodies.

How to Get to the Abandoned Cistern

If you haven’t yet come across the Abandoned Cistern, you’ll find it far west in the in the Lower City’s sewers. You can access the sewers by interacting with the manhole in an alleyway near Bloomridge Park. This will put you by the City Sewers waypoint, and you’ll want to travel up and to the left.

Eventually, you’ll come across a giant pipe you can climb onto and a few cultist enemies. Just past them, you’ll find the Abandoned Cistern’s valve puzzle which will open the Abandoned Cistern itself. If you’re following Jaheira’s High Harper questline, you’ll come here while chasing after Minsc, who will be fleeing the Counting House Vault.

How to Solve the Abandoned Cistern Valve Puzzle in Baldur’s Gate 3

To solve the Abandoned Cistern’s water and temperature valves puzzle, follow these steps:

1. Use the blue valve to the left to increase the water level.
2. Once the water level is at “Perfect Water Level,” use the red valve to the right to increase the temperature level.
3. Once the temperature level hits “Perfect Warmth,” the sluice gate below should open. Head downstairs and exit through the Vault door. 

In the next area, some of Bhaal‘s worshippers await. Short or long rest before stepping in might be a good idea. We also strongly recommend you take Jaheira with you if you’ve progressed past the Counting House Vault in the High Harper questline.

How to Solve the Gardener’s Basement Puzzle to the Abandoned Cistern in Baldur’s Gate 3

Alternatively, you can get to the Abandoned Cistern through the Gardener’s Basement underneath Lady Jannath’s Estate. This is the large mansion located west in Lower City, near the Baldur’s Gate waypoint. Here, you’ll have to solve a different kind of puzzle.

Related: Baldur’s Gate 3: Best Feats For Fighters In BG3

To solve the Gardener’s Basement Puzzle, follow these steps:

1. Ungroup the party to make sure each party member can take a different place.
2. Make one party member stand on the plate on the left side of the Gardener’s Basement.
3. Make another party member stand on the plate on the opposite side.
4. A third party member should go to the now uncovered secret room.
5. Just before entering the underground room, Group the party once again so they follow to the next area.

This leads to the same room with Bhaal’s followers in the sewers near the Abandoned Cistern, so prepare for battle. Once all of Bhaal’s lackeys have been defeated, bring out the strongest companion available. In our case, this was Lae’zel with Astral Knowledge: Strength cast.

Then, interact with the valve to the Vault Door’s left and pass an Athletics check to open the Vault Door in the Abandoned Cistern.