Blocked Drains in Milton Keynes

A city built on Oxford Clay. Milton Keynes sits on Oxford Clay, the same clay that fed the Bletchley brickworks from the 1890s until they closed in September 1990. Clay ground in the south east of England shrinks in dry summers and swells in wet winters, and the British Geological Survey lists tree roots drying the soil as a cause of that movement. A drain run laid in clay moves with it. Joints open, roots find the opening, and the first sign is a blockage that clears and comes back. With 22 million trees and shrubs in the city’s public open space, root ingress is a Milton Keynes problem as much as it is a Victorian one.

Victorian clay pipes in the old towns. Wolverton’s railway terraces, from the 1840s onward, Stony Stratford along Watling Street, Newport Pagnell around the High Street and the 1810 Tickford Bridge, and Old Bletchley around the church. The original drainage here is salt glazed clay in short lengths with many joints, often laid to falls that were generous once and are not now. It cracks, it displaces, and it lets roots in. A camera survey before you buy in these streets is cheap against a collapsed run found after exchange.

Shared runs on the post war and new town estates. The Lakes Estate at Water Eaton follows the Radburn layout, with houses turned towards footpaths rather than the road, and where the 1970s terraces face onto courts and footpaths the drainage will often run behind and between the houses rather than under the street. That is exactly the kind of shared run that passed to Anglian Water in 2011, and knowing which chamber is yours and which is theirs is the first thing we work out on a Netherfield, Beanhill or Coffee Hall call.

Surface water and the balancing lakes. Milton Keynes was designed with its rain in mind. Willen and Caldecotte are balancing lakes that hold flood water from the River Ouzel, Willen alone having capacity for a further 1.3 metre rise, and the floodplains of the linear parks run to about 4,100 acres. That system works at city scale. At house scale, a gully full of leaves, a soakaway that has silted, or a driveway that was paved without thought for where the water goes will still put rain into the house or the neighbour’s garden, and those are the surface water jobs we get called to.

Fats, wipes and the new town kitchen. The same as everywhere. Fat sets in a cold pipe, wipes do not break down whatever the packet says, and together they build a plug that rods push further in. Jetting is the answer, and a five minute conversation about what goes down the sink stops it happening again.