Here is a guide for 11 miscellaneous achievements around Paradise Killer, with this one being the third one.
1. Go to the north end of the map, to the fields.
2. There is a big bridge to the west, and a small one to the east. Go to the east one.
3. Just before the bridge is yellow construction equipment on the left. Here is a valve wheel. Grab it.
4. The next one is just south of this, by a walk way over the water path.
5. The third one is right next to this between the rows of (idk what the rows are made of).
6. South of this is a building, climb it.
7. There will be 3 valve pipes. Put the wheels on to turn on the water.