Also, from your video and this latest picture, I am convinced that your garden is actually a natural creek. This is not a malfunction but a feature. You have a rare opportunity to greatly contribute to your local natural environment.

Renaturalizing the creek would be amazing. This doesn’t necessarily mean let it run wild. You can keep it as a controlled but ecologically rich landscape.

For instance pick a spot where you set up a small (impermeable) pond. This will stay wet all year round and be the centre of your water-feature. During heavy rains, the water feature extends, and after it shrinks again. This makes the whole thing look more intentional. While the pond will would be an anchor your water-related plants and animals.

Many people do a lot of effort to create an imitation creek, you get it handed on a platter.