Industry bosses were summoned to Whitehall last week by Environment Secretary Caroline Spelman to discuss plans for water restrictions after parts of Britain suffered their driest spring in 100 years.
Severn Trent, which serves eight million customers in the Midlands and Wales, has warned it might have to impose hosepipe bans, prompting criticism from trade unions.
The industry also faces the most fundamental reforms to the way it is regulated since privatisation more than 20 years ago. A white paper this autumn could herald the introduction of elements of competition in an industry dominated by regional monopolies.
Speaking last week, Spelman also said the white paper, due by the end of the year, would look at the rules for taking water from rivers.
TLG refused to comment on specifics, but confirmed the appointment by Severn Trent. Association of Professional Political Consultants records show Severn Trent previously used College Public Policy.
The latest APPC register confirms other water companies also have public affairs advisers in place. South West Water and Anglian Water are both using Edelman, while the All Party Water Group - funded by Anglian Water, Southern Water Services, United Utilities, Water UK, Wessex Water and others - uses Connect Communications.