Case Study: 1Spatial achieves rapid, low-cost private sewer mapping with Ordnance Survey

1Spatial - Customer Case Study

water companies faced a major data gap after thousands of private sewers transferred to company ownership, with current quantity estimates carrying a +/-40% confidence interval and Ofwat’s cost pass-through due to end. 1Spatial used geospatial products (leveraging OS MasterMap® and AddressBase®) and the English House Condition Survey matrix to infer private sewer layouts quickly, offering a rules-based, non-programmatic approach to build baseline asset knowledge.

1Spatial implemented common‑language inference rules that combine property boundaries, building age/type and public sewer data to generate fully connected wastewater networks across a company area in hours. The solution—run repeatedly and written into asset metadata as “inferred” records—delivers a connected network at a fraction of previously estimated cost, highlights survey hotspots, links assets to properties, and (working with Tobin Consulting Engineers) supports sampling to reduce the +/-40% confidence interval on transferred-asset quantities.

1Spatial

Mike Sanderson

Strategy Director