In short
- Monitor the entire water column;
- Detect pollutants and harmful events early on;
- Save time and reduce costs.
What is a vertical profiling system?
A vertical profiling system is a monitoring instrument that measures water quality parameters at multiple depths throughout a water column. It integrates a multi-parameter sonde — a submersible sensor unit — that continuously profiles key variables including temperature, dissolved oxygen, pH, chlorophyll a, and turbidity as it moves up and down through the water column.
Unlike fixed surface sensors or periodic manual sampling, a vertical profiler captures the full depth picture of a water body in real time. This matters because water conditions are not uniform from top to bottom — and the difference between depths can determine whether your intake is drawing clean water or algae-laden water at any given moment.
#1 – Monitor at different depths
Monitoring strategies are an essential part of water resource management. In-situ monitoring and manual sampling help keep specific water parameters in check. However, for a complete understanding of a water body, vertical profiling is necessary.
Water characteristics change throughout the water column. Most lakes and reservoirs undergo seasonal cycles of thermal stratification — where warm, lighter water sits above cooler, denser water — creating distinct layers with very different chemical and biological properties. External factors such as wind events, rainfall, and temperature shifts can disrupt this stratification, causing sudden changes in water quality at different depths.
A vertical profiling system continuously tracks these changes. By monitoring temperature gradients throughout the water column, the profiler identifies where thermal stratification is occurring and how it is affecting dissolved oxygen distribution. In stratified conditions, oxygen levels typically decline with depth — in some cases reaching hypoxic levels near the sediment that can stress aquatic life and affect water treatment performance.
This depth-resolved data gives operators a precise understanding of where the highest quality water sits in the water column at any given time — enabling smarter intake selection and more targeted treatment decisions.
For example, by evaluating temperature differences throughout a water column, the profiler helps determine where oxygen increases or decreases. It fosters a better understanding of the aquatic ecosystem and its chemical composition so that you can precisely know which intake is closest to the highest water quality.
#2– Detect algae blooms early on
Cyanobacteria and other harmful algae do not distribute evenly through a water column. During stratified conditions, buoyant cyanobacteria tend to accumulate at specific depths — often concentrating just below the surface or at the thermocline — where light and nutrient conditions favour their growth. Surface sensors alone will miss subsurface accumulations until a bloom has already fully developed.
A vertical profiler installed near a water intake detects elevated chlorophyll a concentrations at depth before a bloom becomes visible or reaches critical levels. This early warning gives operators time to adjust intake depth, activate treatment, or issue operational alerts — avoiding filter blockages, taste and odour events, and the risk of toxin breakthrough into the treatment process.
LG Sonic’s Vertical Profiler can be integrated with the MPC-Buoy system. The profiler identifies the vertical distribution of algae across the water column; the MPC-Buoy then emits targeted ultrasonic programs to disrupt algae growth at the relevant depth. Together, they provide a complete detection-and-treatment response that is safe for fish, aquatic plants, and other organisms.
#3 – Save time and reduce costs
Water quality varies not just across a reservoir’s surface area, but from metre to metre with depth — and those conditions change daily. Manual sampling alone cannot capture this variability reliably. A single grab sample at the surface may look clean, while a subsurface bloom is already forming near the intake.
Combining manual sampling, in-situ surface monitoring, remote sensing, and vertical profiling gives water managers a far more accurate and complete picture of water body conditions. Each method contributes data that the others cannot provide in isolation.
Vertical profiling reduces the operational burden in several ways. Automated, continuous depth profiling eliminates the need for frequent field trips to collect samples at multiple points. Real-time data enables treatment decisions to be made based on current conditions rather than lagging indicators. Early detection of deteriorating water quality reduces the risk of emergency responses, which are significantly more costly and disruptive than preventive action.
For drinking water utilities managing intake quality, the ability to identify the cleanest water layer in real time and optimize intake depth can reduce treatment chemical demand, extend filter run times, and lower overall treatment costs. Over a full operating season, the savings typically outweigh the cost of the monitoring system. This method of proactive water resource management saves you time and costs.
Choosing the right monitoring combination
No single monitoring method provides a complete picture of a water body. The most effective water quality monitoring programmes combine multiple approaches:
- Surface in-situ sensors for continuous real-time measurement of surface conditions
- Vertical profiling for depth-resolved water column data and early bloom detection
- Remote sensing and satellite data for broad spatial coverage and bloom mapping
- Manual sampling for laboratory analysis and calibration verification
LG Sonic’s Vertical Profiler is designed to integrate seamlessly into existing monitoring programmes and can be upgraded to full MPC-Buoy capability as needs evolve.
Want to understand what’s happening throughout your water column? Contact our team to discuss vertical profiling options for your reservoir or lake.