Assuming there is an internal room behind it wouldn't be possible to install the water blade into the wall itself for two reasons; you require quite a substantial depth to accommodate the unit and it needs to be accessible for maintenance.

Perhaps there is a solution to extending the wall above the eaves to combat the above, but I would be extremely cautious about having continuous water running down a wall.

Garden Design to New Build Property - Sneyd Park, Bristol · More Info

Garden Design to New Build Property - Sneyd Park, Bristol · More Info

Just a practical point if you tend to sit facing into the garden you wont be able to see this feature - and though the sound is lovely in itself, being able to watch the water must be at least half the point. These features tend to be built into deliberately created walls as part of the landscape design - have not seen many on house walls.

It is worth considering how much sound any water feature will be making. A little bit of tinkling is probably what you would want. A wide blade of water falling one or two feet or so is likely to seem much too loud after a short while.

Some thing you could safely put on your wall without lots of expenditure or technical troubles would be a mosaic.