Garden Flooded with Sewage

<p>For the third time this year our garden has been flooded with sewage. Jhb Water is quick to respond to unblock the sewage pipe which runs through our garden but I would like to exscalate this problem as there has to be a more permanent solution to this. The guys who come to unblock have said they think the pipes are old and the roots from the many trees along the pipeline have grown into the pipe causing teh pipes to get blocked more frequently. We have children, pets we CANNOT have sewage in our garden every few months. Unblocking the pipe is a reactive and temporary solution to a problem which is getting worse and worse! What do we do????!!!</p>