Ons vermy dehidrasie mits ons genoeg water drink.

Mits means provided that, on condition that, or as long as.

It introduces a condition that must be met. So the idea is:

We avoid dehydration, provided that we drink enough water.

Compared with as (if), mits often sounds a bit stronger or more formal. It suggests a real requirement, not just a possibility.

Because mits introduces a subordinate clause, and in Afrikaans the verb in a subordinate clause usually goes to the end.

So:

• Main clause: Ons vermy dehidrasie
• Subordinate clause: mits ons genoeg water drink

That final drink is normal Afrikaans word order after conjunctions like mits, omdat, dat, as, and others.

Compare:

• Ons drink genoeg water.
• ... mits ons genoeg water drink.

Normally, no. Each clause needs its own subject, so ons appears in both clauses:

• Ons vermy dehidrasie
• mits ons genoeg water drink

English does the same:

• We avoid dehydration provided that we drink enough water.

So the second ons is not unnecessary repetition; it is just standard grammar.

Because Afrikaans verbs usually do not change form for different persons in the present tense.

For example:

• ek drink
• jy drink
• hy drink
• ons drink
• hulle drink

The verb stays the same. That is one of the big differences from English, where you get forms like drink but drinks.

The same is true for vermy:

• ek vermy
• ons vermy
• hulle vermy

In this sentence, dehidrasie is being used as a general abstract noun, so Afrikaans does not need an article.

That is similar to English when we speak about something in general:

• We avoid dehydration
• Ons vermy dehidrasie

If you were talking about a specific case of dehydration, you might use die:

• Die dehidrasie was ernstig.
  = The dehydration was serious.

But in your sentence, it means dehydration in general, so no article is needed.

Because genoeg here works as a quantifier meaning enough, and in normal Afrikaans it comes before the noun:

• genoeg water = enough water
• genoeg tyd = enough time
• genoeg geld = enough money

So ons genoeg water drink means we drink enough water.

Putting genoeg after the noun would sound unusual here and would not be the normal way to express this idea.

Grammatically, it is in the present tense, but in meaning it expresses a general truth or general rule.

So it does not just mean something happening right now. It means something like:

We avoid dehydration if/provided we drink enough water.

Afrikaans present tense often covers:

• what is happening now
• habits
• general truths
• sometimes near-future meaning

Here, the general-truth reading is the natural one.

Yes, you often could, but the nuance changes slightly.

• as = if
• mits = provided that / on condition that

So:

• Ons vermy dehidrasie as ons genoeg water drink.
• Ons vermy dehidrasie mits ons genoeg water drink.

Both are understandable, but mits sounds a bit more like a condition that must be satisfied. It can also sound slightly more formal or careful.

It is a normal Afrikaans word, even though it is clearly an international/learned word and looks similar to English dehydration.

That kind of vocabulary is very common in Afrikaans, especially in health, science, and formal contexts. So dehidrasie is perfectly natural here.

You may also come across other words in some contexts, but dehidrasie is standard and clear.

A rough learner-friendly guide would be:

• genoeg ≈ khuh-NOOKH or ghe-NOOKH
• dehidrasie ≈ dee-hee-DRAA-see

A few useful points:

• The g in Afrikaans is usually a throaty sound, not the English g of go.
• The oe in genoeg sounds like oo in food.
• The stress in dehidrasie falls on DRAA.

Even if your g is not perfect yet, people will usually still understand you from context.