Central Drains

It sounds like the natural fall of the land runs towards the storm drain in the road anyway. when paying your water rates you’ll notice a section covering the road drainage around your property also. it is generally legal to divert rainwater from your property to the street or a public drain as long as it does not cause any damage, flooding or blockages. however, it is always best to check with your local council or water authority to ensure you are not in breach of any regulations or bylaws. additionally, it is important to consider the impact your actions may have on the environment and neighboring properties.

Would this downspout be coming from the roof guttering by chance ? it is possible to have a combined network. in which both storm and foul leaves your property on the same line. but this is not always the case. factors of any sort of building extensions also come in to play. your local water authority should be able to tell you if you have a combined or separate network from their records.