La ruta de evacuación evita el riesgo doméstico.

Because ruta is a feminine noun in Spanish, so it takes la.

• la ruta = the route
• una ruta = a route

This is something you mostly have to learn with the noun. The ending -a often suggests a noun is feminine, and ruta follows that common pattern.

Spanish very often uses the pattern noun + de + noun where English might use a noun as an adjective or a compound noun.

So:

• ruta de evacuación = evacuation route
  literally, route of evacuation

This is a very natural and common structure in Spanish. Other examples:

• plan de emergencia = emergency plan
• salida de incendios = fire exit
• centro de salud = health centre

A more adjective-based version is sometimes possible in Spanish, but ruta de evacuación is the normal, idiomatic choice.

Because de + noun often works as a classifier in Spanish: it tells you what kind of route it is.

So ruta de evacuación means:

• a route used for evacuation
• an evacuation route

If you said ruta de la evacuación, it would usually sound like you mean the route of the evacuation, referring to a specific evacuation event, which is a different idea.

Compare:

• ruta de evacuación = evacuation route, a type of route
• ruta de la evacuación = the route taken in the evacuation / the route of the evacuation

Evita is the third-person singular present indicative of evitar.

So:

• yo evito = I avoid
• tú evitas = you avoid
• él / ella / usted evita = he / she / you avoid(s)

In this sentence, the subject is la ruta de evacuación, which is singular, so the verb is evita.

Because the whole subject is la ruta de evacuación, and the head noun is ruta, which is singular.

Even though the subject contains several words, it is still just one route, so the verb must be singular:

• La ruta de evacuación evita...

If the subject were plural, the verb would change too:

• Las rutas de evacuación evitan...

Because riesgo is a masculine singular noun, so it takes el.

• el riesgo = the risk
• un riesgo = a risk

The article also agrees with the adjective:

• el riesgo doméstico
• los riesgos domésticos

In Spanish, most adjectives normally come after the noun.

So:

• riesgo doméstico = domestic / household risk

This is the standard position for a descriptive or classifying adjective. Putting it before the noun would sound unusual here and could change the tone or emphasis.

Very roughly:

• noun + adjective = neutral, standard description
• adjective + noun = often more literary, subjective, or emphatic

So el riesgo doméstico is the normal order.

Here doméstico means something like related to the home or household.

So it can describe something that belongs to the domestic sphere:

• accidente doméstico = household accident
• riesgo doméstico = household / domestic risk

For English speakers, it is worth noting that doméstico does not always mean exactly the same thing as English domestic in every context. Depending on the sentence, it can mean:

• household
• home-related
• domestic

So you should learn it by context, not assume it always matches English perfectly.

Yes, depending on context, evitar can often mean either to avoid or to prevent.

In grammar terms, the sentence structure here is:

• subject + evitar + direct object

So literally:

• La ruta de evacuación evita el riesgo doméstico.
• The evacuation route avoids/prevents the domestic risk.

Which English translation sounds best depends on the context already given to the learner. Spanish evitar often covers both ideas more flexibly than English.

Because the personal a is mainly used before specific human direct objects.

Here, el riesgo doméstico is a thing/abstract concept, not a person, so there is no personal a.

Compare:

• Veo la salida. = I see the exit.
• Evita el riesgo. = It avoids the risk.
• Veo a María. = I see María.

So evita el riesgo doméstico is exactly what you would expect.

Evacuación has the written accent because the stress falls on the last syllable:

• e-va-cua-CIÓN

The accent mark shows that final stress clearly.

In standard Spain Spanish, the c before i in -ción is pronounced like th in think:

• evacuación → roughly eh-bah-koo-ah-THYON in Castilian pronunciation

In many other Spanish-speaking regions, it is pronounced with an s sound instead:

• eh-bah-koo-ah-SYON

Both are correct in their respective varieties; for Spain, the th sound is the usual one.

Doméstico is stressed on the syllable més:

• do-MÉS-ti-co

It has a written accent because words ending in a vowel are normally stressed on the second-to-last syllable, but doméstico is stressed earlier than that, so the accent mark is needed.

In Spain Spanish, a rough guide would be:

• doh-MES-tee-koh

The accent mark does not change the vowel quality very much; its main job is to show where the stress goes.

Yes, but it would mean something slightly different.

• evita el riesgo doméstico = avoids the domestic risk / household risk
  This can sound more specific or more general in a formal, abstract way.

• evita riesgos domésticos = avoids/prevents household risks
  This sounds more plural and more general: different kinds of household risks.

Both are grammatically possible. The choice depends on the intended meaning and style.

Spanish word order is somewhat flexible, but this version is the most neutral and natural:

• La ruta de evacuación evita el riesgo doméstico.

You could rearrange parts for emphasis, but that would usually sound less neutral. For example:

• El riesgo doméstico lo evita la ruta de evacuación.

That is grammatical, but much more marked and emphatic. For a learner, the basic subject + verb + object order is the best model here.