What is the meaning of rendered here?

Question

800 km of district roads and 266 km of provincial roads were RENDERED impassable, 403 bridges became unusable and 12 ports and piers destroyed.

Answer 1

In this context it means "made" ... or "became" impassable by whatever happened/transpired (ie weather, accident, fire, etc.)

roads were made impassable

roads became impassable

Answer 2

Yes. "provincial roads were MADE impassable".

Answer 3

in that context the meaning is "caused to become"