Dig a 30 x 30 x 30 hole in 3 different locations in your garden.
Digging a hole in several locations in your yard will give you a good average picture. After all, there may just be a piece of debris, plastic or wood under the dug hole.

Then empty a bucket of water into each dug hole. Is the water drained away within half an hour then you have a good permeable soil. Which is certainly suitable for water infiltration.

Is the water still not completely gone after 4 hours? Then you know for sure that you have a poorly permeable soil. Often you then have a peat or clay soil, on this soil a water garden in which water can infiltrate well is often not recommended.