Water Industry Glossary

The eighth five-year investment cycle for the UK water industry, running from April 2025 to March 2030. Ofwat's PR24 Final Determination confirmed approximately £104 billion of investment across all regulated water companies in England and Wales during this period. AMP8 is the largest capital programme in the sector's history, driven by requirements to reduce storm overflows, cut leakage, upgrade wastewater treatment and improve water supply resilience. Scottish Water has its own regulatory framework but operates on a similar cycle.

The network of smart water meters, communications systems and data management platforms that enable water companies to collect consumption data automatically and continuously. AMI meters transmit readings hourly or more frequently (compared to annual or bi-annual reads for traditional meters), enabling real-time leakage detection on customer supply pipes. All UK water companies are rolling out AMI under their AMP8 leakage and per capita consumption performance commitments. NB-IoT is the dominant communications standard for UK water AMI.

A legal requirement under the Environment Act 2021 (mandatory from February 2024 for major developments) that new development delivers at least 10% improvement in biodiversity value compared to the pre-development baseline, measured using Natural England's Biodiversity Metric. AMP8 capital projects are subject to BNG requirements. Water companies and their Tier 1 contractors must calculate BNG metrics and provide compensation for any residual biodiversity loss through on-site habitat creation or off-site biodiversity units.

A method of pipe rehabilitation in which a resin-saturated felt liner is inserted into an existing deteriorated pipe and then cured (hardened) in place using hot water, steam or UV light. The cured liner creates a new, structural pipe inside the old one, without the need for excavation. CIPP is the dominant method for sewer and water main rehabilitation in AMP8 due to its low disruption, cost-effectiveness and ability to handle complex pipeline routes.

The UK's independent competition and consumer authority. Under the Water Industry Act 1991, a water company that believes its Ofwat price determination is fundamentally flawed can refer it to the CMA for an independent redetermination. Five companies (Anglian, Northumbrian, South East, Wessex and Southern) referred their PR24 determinations to the CMA. The CMA issued its final determinations in March 2026, confirming the overall £104bn investment level with marginally improved financial terms for the referring companies.

A point on a combined sewer (one that carries both sewage and surface water runoff) designed to overflow into a watercourse during heavy rainfall when the sewer would otherwise be overwhelmed. CSOs are legal under Environment Act permits but have attracted intense public and regulatory scrutiny due to excessive frequency of spills. AMP8 includes approximately £12 billion dedicated to reducing CSO spill frequency and volume. Also referred to as storm overflows.

The company responsible for operating the local electricity distribution network (cables from the National Grid to homes and businesses). DNOs are relevant to water sector capital programmes because electrical upgrades at water treatment works and pumping stations require DNO agreement for new or upgraded connections. Managing DNO timescales — often 18–36 months for new connections — is a critical programme risk on large AMP8 capital projects.

A competence framework and register for workers in the gas, power and water industries. EUSR manages the WIRS/WIRSAE schemes for the water sector and issues EUSR cards to certified workers. Holding a valid EUSR card — and the underlying competence record — is typically required for anyone working on water company sites. The card proves the holder has completed relevant training, holds the correct accreditations and has been registered against their National Insurance number.

Ofwat's binding regulatory decision at the end of each price review that sets the allowed investment, revenue and performance commitments for each water company for the following five-year period. The PR24 Final Determination was published in December 2024. Five companies appealed to the CMA; the CMA's final determinations were issued in March 2026. A final determination cannot be changed except through a CMA redetermination or a formal modification agreed by the company and Ofwat.

A trenchless pipeline installation technique in which a pilot bore is drilled at a shallow angle and then enlarged to accommodate the pipe being installed. HDD is used for crossing roads, railways, rivers and other obstacles where open-cut excavation is impractical or prohibited. Common for large-diameter water mains and rising mains crossing watercourses or infrastructure. A steerable variant allows complex curves.

The sub-discipline within MEICA covering process sensors, analysers, PLC/HMI systems, SCADA, telemetry and operational technology. ICA contractors design, install, commission and maintain the control systems that regulate water treatment processes and pump operations. OT (operational technology) cybersecurity is an emerging ICA obligation under AMP8 given increasing connectivity of water infrastructure to corporate networks.

A wireless communications technology used for IoT devices including smart water meters. LPWANs operate on unlicensed spectrum and are optimised for low data rates, long battery life and wide geographic coverage. NB-IoT (Narrowband IoT, operating on licensed 4G/5G spectrum) and LoRaWAN (operating on unlicensed 868MHz spectrum) are the two dominant LPWAN standards used in UK water smart metering deployments.

The umbrella term for process plant and control systems work in the water sector. A MEICA scope typically covers mechanical installation (pumps, valves, screens, mixers), electrical (MCC panels, cabling, earthing), instrumentation (sensors, flow meters, analysers), control systems (PLCs, HMIs) and automation (SCADA, telemetry). MEICA is the most in-demand and highest-value specialist skill category in AMP8, required at every water treatment works and wastewater treatment works upgrade project.

The standard form of contract used for approximately 80% of AMP8 water sector framework appointments. Published by the Institution of Civil Engineers (ICE), NEC4 is designed to facilitate collaborative working through shared risk, early warning obligations and active programme management. Key contract options include Option A (priced activity schedule), Option C (target cost with pain/gain share) and Option E (cost reimbursable). Most AMP8 subcontracts are let on NEC4 Engineering and Construction Subcontract (ECS) terms, back-to-back with the main contract.

A low-power wireless communications standard using licensed 4G/5G spectrum for IoT devices. NB-IoT has become the dominant communications technology for UK water sector smart metering following Thames Water's £48.5m, 204,700-meter contract with Vodafone. Its key advantages over proprietary mesh networks are deep building penetration, nationwide coverage on existing cellular infrastructure, and no requirement for the water company to operate its own radio network.

The economic regulator of the water and sewerage industry in England and Wales. Ofwat sets price determinations (every five years through the price review), monitors company performance against commitments, and can impose financial penalties, special administration orders or enforcement notices. In Scotland, the equivalent regulator is WICS (Water Industry Commission for Scotland). In Northern Ireland, the Utility Regulator oversees Northern Ireland Water.

Ofwat's regulatory price review process that determined water company investment and revenue allowances for the period April 2025 to March 2030 (AMP8). Ofwat published its Final Determination in December 2024, confirming £104bn of investment. Five companies (Anglian, Northumbrian, South East, Wessex, Southern) appealed to the CMA. The CMA issued its final determinations in March 2026, confirming investment levels with marginally improved financial returns for the five referring companies.

A formal procurement notice that contracting authorities (including water companies above the utility threshold) must publish before going to market for contracts over £2 million. Introduced under the Procurement Act 2023 (effective October 2024), pipeline notices give suppliers early sight of upcoming procurement — typically 12–24 months in advance. They are the most valuable early-warning signal available to water sector suppliers wanting to position themselves ahead of formal tenders.

A mechanism within an Ofwat price determination that allows a water company to apply for additional revenue funding during an AMP if its actual costs significantly exceed the allowed expenditure — typically because of an unforeseen event, new legal obligation or cost uncertainty that could not be anticipated at the time of the determination. AMP8 includes several defined reopener mechanisms including those for storm overflow delivery and large-scale strategic resource options.

The software and hardware system used by water companies to remotely monitor and control their treatment and distribution assets. A SCADA system aggregates data from thousands of sensors and instruments across a water company's network — treatment works, pumping stations, reservoirs — and displays it to operators in a control room. Water company SCADA upgrades are a significant AMP8 procurement category, driven by OT cybersecurity requirements and the need to integrate smart metering data.

An Ofwat enforcement mechanism applied to a water company with serious and sustained operational or financial failure. A company under TOR must meet defined turnaround milestones — set by Ofwat — as a condition of accessing its full AMP8 funding. Thames Water was placed under TOR in 2024 due to its financial difficulties and operational performance issues. TOR obligations add additional complexity for supply chain companies working on Thames Water programmes and require close monitoring of payment terms.

A cross-utility pre-qualification and accreditation database operated by Achilles, covering electricity, gas and water industries. Many UK water companies use UVDB as a pre-qualification requirement for their supply chains, alongside or instead of WIRS. UVDB modules include Community (basic health, safety and environmental information), Verify (independently verified module), and Technical (specific technical assessments by sector).

Electrical devices used to control the speed of pump and blower motors, allowing them to operate at the most energy-efficient speed for the required flow or pressure. VSDs are standard specification on new and refurbished water and wastewater pumping stations under AMP8 energy efficiency obligations. ABB, Siemens and Schneider Electric are the dominant VSD manufacturers in the UK water sector.

The rate of return that investors in a regulated water company require, blending the costs of debt and equity weighted by their share of the company's financing structure. Ofwat uses WACC as a key input in setting the allowed revenue for each water company — a higher WACC allows more revenue and therefore more financial headroom for investment. The WACC was a central dispute in the PR24 CMA appeals, with all five referring companies arguing that Ofwat's assumed WACC was too low given post-2022 interest rate levels.

EU legislation (transposed into UK law and retained post-Brexit as the Environment (Retained EU Directive) (Amendment) Regulations 2023) that requires all water bodies — rivers, lakes, estuaries, groundwater — to reach "good ecological status" or "good ecological potential." Water company obligations under the WFD drive much of the WINEP programme — particularly phosphorus reduction, improved wastewater effluent quality and abstraction reform.

The statutory programme of environmental improvement obligations that all UK water companies must deliver, developed jointly by Ofwat, the Environment Agency and Natural Resources Wales. WINEP obligations in AMP8 include: phosphorus removal improvements at wastewater treatment works, storm overflow screening and monitoring, abstraction reform to reduce environmental damage, flow to good ecological status improvements, and biodiversity net gain. WINEP work is funded within the PR24 allowance and is legally binding.

The primary contractor pre-qualification accreditation for working in the UK water sector, operated by EUSR (Energy & Utilities Skills Register). WIRS covers civil, mechanical and general water sector activities. WIRSAE (WIRS Authorised Electrician) is the scheme for electrical work on water company sites. WIRS registration involves verification of health and safety systems, competence frameworks and insurance — and is required by most water company frameworks as a minimum pre-qualification criterion.

A Water Treatment Works (WTW) is a facility that treats raw water from an abstraction source to drinking water standard before distribution. A Wastewater Treatment Works (WwTW) — sometimes called a sewage treatment works (STW) — treats wastewater from sewers before returning it to the environment. Both types of works are major capital investment locations in AMP8, with significant MEICA, civil engineering and process engineering scopes.