Following are a number of back-translations as well as a sample translation for translators of Joel 3:18:

• Kupsabiny: “When that day comes,
  there will be much sweet wine on the mountains.
  Milk in/on the hill will be much
  and there will be water in all the valleys of Judah.
  A spring will come up/forth from the Homestead of God
  and pour its water into the valley of acacia.” (Source: Kupsabiny Back Translation)
• Newari: “On that day, sweet wine will flow down from the mountains
  and hills will flow with milk.
  All the rivers of Judah will flow with water.
  A fountain will burst forth from the temple of the Lord
  and will wet the valley of Shittim. ” (Source: Newari Back Translation)
• Hiligaynon: “In that time I will-bless you (plur.). Your (plur.) new wine will-be-abundant from many grapes in mountains. Your (plur.) milk will- also -be abundant from many cows and goats that graze on the hills/[lit. small-mountains]. Your (plur.) streams will- never -dry-up. And the spring from the temple of the LORD will-flow and it will-cause-to-be-watered in the dry place-where- water -flows that has acacia-(trees).” (Source: Hiligaynon Back Translation)
• Kankanaey: “At that time, the mountains will be planted with grapes and cows will become-many on the hills. There will also be much water in Juda and there-will-be a spring that comes-from the Temple of God which waters the valley/plain Acacia (i.e. plain called Acacia or Acacia Valley).” (Source: Kankanaey Back Translation)
• English: “At that time, there will be vineyards covering the hills,
  and your cattle and goats on those hills will produce plenty of milk.
  The streams in Judah will never dry up.
  And a stream will flow from my temple into the Acacia Valley northeast of the Dead Sea.” (Source: Translation for Translators)