Drainage on a long narrow Warwick plot has one recurring problem: distance. A run from the back of a deep garden to the connection at the front has a long way to travel and not much height to do it in.
Fall is the whole game. Too little and it silts up and blocks repeatedly; too much and the liquid outruns the solids with the same result. On a plot that runs a hundred feet back, the difference between a drain that works for fifty years and one that blocks every winter is a matter of millimetres per metre set correctly at the start. We survey the levels rather than eyeballing them.
Where a run belongs to the water company rather than to you, and since 2011 a great many do, building over or close to it needs consent granted before the concrete goes in. It is a routine application and a serious problem to be caught without, because it emerges during a sale.
In the historic core there is an extra consideration. An excavation may attract an archaeological condition, and a drainage trench is an excavation like any other. Where that applies it changes the programme, and it is better known when budgeting.
Our drainage work page covers surveys, repairs and new connections.