The Environment Agency’s Hydrometry teams monitor water quantity across rivers, streams, lakes, and groundwater aquifers. Hydroacoustic instruments are used to measure water discharge in these environments. A hydroacoustic contract is required to secure specialist services and equipment that utilise sound in water to achieve objectives not feasible with other technologies. Area Hydrometry and Telemetry teams purchase and operate these instruments, with technical support and procurement guidance provided by the National Hydrometry team. The Environment Agency has selected hydroacoustic instruments as a highly accurate, long-term, and cost-effective solution for measuring water. These instruments support both routine measurements and long-term monitoring programmes, which are critical for: Trend Analysis – Tracking changes in river flows, lake levels, and groundwater over time to understand hydrological patterns. Flood Risk Management – Providing accurate discharge data to improve flood forecasting and early warning systems. Climate Resilience – Assessing the impact of climate change on water resources and informing adaptation strategies. Regulatory Compliance – Meeting statutory obligations for water quantity reporting and supporting environmental legislation. Infrastructure Planning – Supplying data for water resource management, reservoir operations, and sustainable development. The instruments fall into three main categories: Mobile profiling instruments Waded point-velocity instruments Fixed-deployment profiling instruments To facilitate procurement and ensure continuity of long-term monitoring, the Environment Agency intends to establish commercial agreements for a fixed two-year period with an optional 1 year extension covering the following lots: Lot 1. Mobile acoustic profiling instrument 0-20m depth Lot 2. Mobile acoustic multipoint velocity waded instrument 0-1m depth Lot 3. Short range fixed velocity profiling instrument 0-5m Lot 4. Long range fixed velocity profiling instrument 0-100m The following UK public sector bodies are authorised and enabled to use the contract, The Environment Agency (EA), Natural Resource Wales (NRW) and the Scottish Environment Protection Agency (SEPA).