Here is my situation.
We have a large storm drain that runs exactly parallel to the front wall of our house and we have 2 drainage pipes that lead from our garden straight into the storm drain. Both the pipes are about 10cm diameter. They lead from our garden at about a 20 degree angle into the main drain.
Now, when it rains really hard or if the the main storm drain can't handle all the water, our garden and house flood because all the water comes out of the storm drain, through the 2 pipes and into our place.
Does anyone know of any kind of valve system I could fit to the drains to stop this happening?
I can't just block them up because we need them most of the time for drainage.
Any ideas?