Image by Jaanus Jagomägi


Client: Thames Water


Thames Water is the largest water and waste water company in the UK, providing services to millions of people across London and Thames Valley region. 

To support its Price Review submission to Ofwat, Thames Water sought to compile updated and improved evidence on the effect of transience (movement of population into and out of residential properties) upon its area of operation compared to that of other water companies across the UK.

Transience is a key determinant of variable levels of water debt, particularly in those areas where private rented accommodation proliferates.


The new evidence on transience was formulated by Edge Analytics using a number of sources, each providing a particular perspective on the relative effect of population movement on residential properties served by the water companies of England & Wales.

The latest migration statistics from ONS (both domestic and international) provided the basis for transience analysis from a demographic perspective.

Property and transactions data from the English Household Survey, Census, Land Registry and Zoopla provided transience statistics from a property perspective, classifying based on tenure type (owner occupied, social rented, private rented).

The project deliverable consisted of a report summarising key findings and providing details of methods, data and assumptions. This was accompanied by a Transience Model workbook containing detailed data, allowing closer scrutiny and further analysis of the spatial variations evident in the movement of population into and out of properties by tenure.