From Dust

You can get this as of the 4th level "First Power"
You will encounter a volcano with a never ending supply of lava for you, you will need the lava to build up the walls to complete you goal to finish the level but that is achieveable without reaching the amount you need to move for the achievement.
From my calculations you need about 50 full loads so if you want to speed things up hover over a lava pool hold LT and when the control vibrates signifiying a full load let go of LT and then press RT & LT together (This does an instant dump of all the lava)

Note: The achievement is cumulative so if you don't get it the first time it doesn't mean starting again, you will more than likley get this through standard playthrough but if it is an issue later in the game you will encounter more volcanoes and will have the power 'Amplify Breath' which will speed things up immensley

You can get this on the first island you encounter the Volcanoe, just keep draining the lava pools and using it to reinforce your tsunami wall. Hover over the lava pools and hold LT to pick it all up.