Flow Survey Services for Flood Risk, Drainage and Sewer Networks
Flow surveys provide accurate data on how water moves through rivers, watercourses, culverts and sewer network catchments. By measuring flow velocity, depth and discharge, Cura Terrae Water builds a clear, defensible picture of how a system behaves under different conditions, supporting flood risk assessments, drainage modelling, pollution investigations and infrastructure design.
Local authorities, developers, water companies, engineering consultancies and infrastructure owners commission our surveys when they need reliable flow data for planning applications, consent assessments or network capacity studies. This page sets out what we do, how we do it, and what you can expect from the process.
Ready to discuss your project? Contact Cura Terrae Water to request a proposal, talk through site conditions, or send existing model and network plans for review.
What Is a Flow Survey?
A flow survey measures the movement of water through a river, culvert, sewer network or open channel over time. It captures flow rate, velocity and depth data to support regulatory compliance, infrastructure planning and environmental management.
Whether you’re planning a flood alleviation scheme, assessing catchment response, or gathering baseline flow data, we offer a full-service solution tailored to the monitoring needs of natural and engineered watercourses.
Our Flow Survey Services
Cura Terrae Water offers an end-to-end flow survey service, from survey design and installation through to data processing and reporting. These can be commissioned as a complete package or selected individually to support existing project teams.
Survey Design and Site Scoping
Every survey begins with a thorough understanding of your site and project objectives. This includes assessing catchment characteristics, access, expected flow conditions, and the purpose of the data collection. A tailored flow survey strategy is then developed to identify the right monitoring points and create the right data collection approach for the project objective, whether you need data for modelling, planning consent, or post-event analysis.
Flow Monitoring and Data Logging
We deploy high-accuracy sensors to record flow rate, velocity and depth, with flow data logged at 2-minute intervals during a flow survey and collected over several weeks to ensure a representative dataset across a range of weather and operational conditions. Our equipment includes area velocity probes, pressure transducers, ultrasonic flow meters, velocity profilers and bi-directional flow monitoring, allowing us to monitor baseflow, stormflow and intermittent discharges with precision for assessing performance and network performance under changing weather and operational conditions.
River Gauging and Velocity Profiling
For open channels and rivers, we perform river gauging using multiple instruments across a measured cross-section. This involves measuring flow depth and velocity through the water column, establishing cross-sectional area, and resolving accurate flowrates over time. Cross-sections are selected to minimise turbulence, backflow or bed movement. Where standard methods aren’t feasible, we use dilution gauging as an alternative approach.
Rainfall Monitoring
Rainfall plays a crucial role in interpreting river flows. We install automated rain gauges at strategic points around the catchment to record rainfall intensity and volume at high resolution. This rainfall data is synchronised with flow data to support event analysis, model calibration or consent assessments.
Event-Based Flow Surveys
To capture the dynamics of specific flow events , such as storm surges, CSO spills or flash flooding , we deploy event-based monitoring. Equipment is triggered by rainfall exceedance, river level rise, flow rate thresholds, or manual or remote activation. This ensures key data is captured during short-duration or high-impact events that typical monitoring might miss.
Dilution Gauging for Complex Conditions
When conventional flow measurement isn’t practical, for example in shallow or turbulent rivers, we use dilution gauging. This involves introducing a tracer into the flow and measuring its dilution downstream to calculate discharge. It’s ideal for small channels, culverts and difficult-to-access locations.
Data Processing and Flow Analysis
All flow data is quality-checked and analysed by our in-house data team. We provide detailed and summarised reports, including daily minimum, maximum, average and total flowrates, time series graphs and hydrographs, event-based discharge volumes, and flow duration curves and statistical summaries. We deliver data in a format ready for regulators, modellers or planning submissions.
Remote Telemetry and Live Data Access
For sites requiring live data or rapid response, we offer telemetry-enabled flow monitoring systems. These stream data to our secure portal, allowing live access to flow data, automated alerts for exceedances, near real-time reporting and remote system management. We also integrate data with eDAS, our cloud-based environmental data acquisition system.
Long-Term Flow Survey Deployment
We provide fully managed long-term monitoring solutions for infrastructure development, flood risk studies and baseline data collection. Equipment can be installed and maintained for weeks or months, depending on project needs, with data handled securely and reported at agreed intervals.
eDAS Environmental Data Acquisition and Reporting
All flow survey data can be centralised through eDAS, our in-house environmental data platform. eDAS provides secure, user-friendly dashboards, centralised data from multiple locations, automated reporting and trend visualisation, and custom access for stakeholders and project teams.
Discuss a Flow Survey with Cura Terrae Water
If you have a river, catchment, development site or sewer network that needs measured flow data, contact Cura Terrae Water to discuss your requirements. We deliver integrated flow, rainfall and event-based monitoring with clear reporting and eDAS-based data access, producing datasets that support modelling, planning and compliance decisions.
