Project

Thames Tideway Tunnel

United KingdomEnvironmental Infrastructure, Wastewater Infrastructure, Water Infrastructure, Tunnel Infrastructure, Urban InfrastructureReviewed 18 August 2026

Major regulated wastewater infrastructure project beneath London, delivered through a standalone infrastructure provider and financed through private capital supported by regulated customer revenue.

Status

OperationalStatus
CompletedProcurement Status

Value

GBP 4.7 billionProject Value

Scale & Capacity

25 km kmMain Tunnel Length
7.2 mMaximum Tunnel Diameter

Overview

Location
London, United Kingdom
Structure
Regulated Infrastructure, Specified Infrastructure Project
Delivery Model
Regulated Infrastructure Provider Model
Financing
Private Equity + Long-Term Debt / Regulated Utility Finance
Revenue / Payment Model
Regulated Customer Revenue
Scale / Scope
Major wastewater tunnel system beneath London comprising a main tunnel, connection tunnels, deep shafts, interception structures and associated infrastructure.

Participants & Roles