Hou water gereed ingeval die watertenk leeg raak.

Because this is a command or instruction. In Afrikaans, commands usually leave out the subject pronoun, just like English often does:

• Hou water gereed. = Keep water ready.
• Wag hier. = Wait here.
• Luister mooi. = Listen carefully.

If you added jy, it would usually sound more marked or emphatic rather than like a normal instruction.

Here hou means keep.

So Hou water gereed means Keep water ready.

This is a very common use of hou in Afrikaans:

• Hou die deur oop. = Keep the door open.
• Hou dit veilig. = Keep it safe.
• Hou kos warm. = Keep food warm.

So hou + object + adjective/state is a useful pattern.

Gereed means ready. In this sentence it describes the state the water should be kept in.

So the structure is:

• Hou = keep
• water = water
• gereed = ready

Together: Keep water ready.

This is similar to English word order in phrases like:

• keep it safe
• keep the door closed
• keep food warm

So gereed is not a separate action; it tells you the condition of water.

Yes. Ingeval means in case.

In this sentence:

• ingeval die watertenk leeg raak = in case the water tank runs empty / becomes empty

It is a normal and common way to introduce a clause about a possible situation.

You may also see related words like:

• indien = if / in the event that
• as = if / when

But ingeval is especially good for precaution or preparation, which fits this sentence very well.

Because ingeval introduces a subordinate clause, and in Afrikaans subordinate clauses usually send the finite verb to the end.

Main clause:

• Hou water gereed.

Subordinate clause:

• ingeval die watertenk leeg raak

That final raak is normal after a subordinating word like ingeval, as, omdat, terwyl, etc.

Compare:

• Ek bly tuis omdat ek siek is. = I stay home because I am sick.
• Bel my as jy arriveer. = Call me if you arrive.
• Neem 'n jas saam ingeval dit koud word. = Take a jacket along in case it gets cold.

So the end position of raak is a grammar feature, not a special meaning.

Good question. Raak can mean different things depending on context.

Here it does not mean touch. Here raak means something like:

• become
• get
• come to be

So:

• leeg raak = become empty / run empty

This is a very common Afrikaans pattern:

• moeg raak = get tired
• kwaad raak = get angry
• vol raak = become full
• weg raak = get lost

So in this sentence, die watertenk leeg raak means the tank may become empty.

Because leeg raak focuses on a change of state.

• leeg wees = to be empty
• leeg raak = to become empty / run empty

In this sentence, the idea is not simply that the tank is empty right now. The idea is that it might become empty, so raak is the natural choice.

Compare:

• Die bottel is leeg. = The bottle is empty.
• Die bottel raak leeg. = The bottle is getting empty / becoming empty.

Die means the, so die watertenk means the water tank.

This suggests a specific tank that the speaker and listener both know about, for example the tank in a house, building, or system.

If you said 'n watertenk, that would mean a water tank, which sounds less specific.

So the sentence is talking about a particular known tank, not just any tank.

Yes. Afrikaans normally writes compound nouns as one word.

So:

• water
  • tenk = watertenk

This is very common in Afrikaans, just as in Dutch and German. More examples:

• huisdeur = house door / front door
• sonlig = sunlight
• skooltas = school bag

English often uses separate words where Afrikaans prefers a single compound word.

Yes, depending on context. Water is the object of hou, so it is what you are being told to keep ready.

You could replace it with other nouns:

• Hou kos gereed = Keep food ready
• Hou kerse gereed = Keep candles ready
• Hou 'n flits gereed = Keep a flashlight ready

If water were omitted, the sentence would feel incomplete unless the object were already strongly understood from context.

Yes: hou ... gereed is a very natural Afrikaans expression for keep ... ready or have ... ready.

You will hear the same pattern often:

• Hou jou paspoort gereed. = Keep your passport ready.
• Hou die dokumente gereed. = Keep the documents ready.
• Hou ekstra batterye gereed. = Keep extra batteries ready.

So this sentence is not unusual or literary; it sounds like normal practical Afrikaans.

Yes, but the original order is very natural.

Original:

• Hou water gereed ingeval die watertenk leeg raak.

You could also front the ingeval clause for emphasis:

• Ingeval die watertenk leeg raak, hou water gereed.

That means the same thing, but it puts more focus on the possible problem first.

Both are correct. The original version sounds direct and instruction-like.

It is most commonly followed by a clause, as in this sentence:

• ingeval die watertenk leeg raak

That clause has its own subject (die watertenk) and verb (raak).

In everyday Afrikaans, people may also use expressions with vir ingeval in looser speech, but for a sentence like this, ingeval + clause is the standard pattern to learn.