Copper gutter
The water around your house is controlled by the guttering system of your home. The basement is protected from the moisture that can accumulate in your basement avoiding a lot of problems. Gutters can be made from lot of materials, a very popular one being vinyl.
Testing the strength of the gutter against rain is a thing you can only make by reading existing materials about this. You can only make a wise estimate about the gutter’s durability because there are no available standards or rating methods.
Check the vinyl thickness. For strong weather you should have a vinyl thickness of about 0.27”. But still vinyl is not so recommended to use in strong weather because it is a fairly lightweight material and when facing heavy rains and weather conditions it may break or warp. You can still prevent this from happening if you clean it regularly.