Water monitoring in reservoirs requires continuous depth profiles – previously only possible manually from boats. This profiler winch fully automates the process: Up to 8 times daily, an OTT HydroLab 7 probe captures oxygen, temperature, pH value, and algae concentration across the entire water column. The measurement data flows directly into the central control system of the Aabach reservoir, which supplies drinking water to 200,000 residents. The result: Comprehensive data monitoring for optimal operation of the deep-water aeration system – without manual boat trips.
Technologies Used:
- Siemens S7-1200 PLC
- OTT HydroLab 7 multiparameter probe
- OTT netDL 1000 data logger
- Unigate MB protocol converter
- Custom winch design (100m cable capacity)
Monitoring Winch Aabach Reservoir
Automated depth profile acquisition with MEDIRA monitoring winch & OTT HydroLab 7
Background
The Aabach reservoir, with a length of approximately 3 km, a width of up to 1.5 km, and a total storage capacity of around 20 million m³, secures the drinking water supply for more than 200,000 residents in the districts of Paderborn, Soest, Gütersloh, and Warendorf and makes an important contribution to flood protection. The dam has a length of 450 m and contains, in addition to the flood relief, the bottom outlet and operational outlets for raw water extraction at various levels.
To ensure water quality, the reservoir has a deep-water aeration system that is activated via a central control system when needed. In 2019, the aging existing system was replaced by two TIBEAN units from Polycon GmbH, providing a potential oxygen input of approximately 400 kgO₂ per day. The complete system now consists of two TIBEAN units installed at prominent topological positions. They are telescopic, so fluctuating water levels are automatically compensated. One of the two TIBEAN units is additionally equipped with a profiler winch.
Task
Monitoring oxygen input is essential today for the efficient and ecologically sound operation of a deep-water aeration system. Water temperature and dissolved oxygen in the water body are key parameters for good operational and water monitoring. Setting up automated, continuous measurement data acquisition was the focus of this project. Integration into the central data center and control system of the Aabach reservoir was among the additional requirements.
Monitoring Solution
A winch performs daily profile acquisition runs, during which an OTT HydroLab 7 multiparameter probe captures measurements in meter increments across the entire water column. The data is synchronously logged with an OTT NetDL1000 and made available to the data center of the Aabach Reservoir Water Association. Additionally, there is a connection to the controlling PLC via a Unigate MB protocol converter. This allows the query and provision of probe parameters to be synchronized with the control process.
In addition to automated daily acquisition, profile acquisition can be triggered at any time via the control room. Additionally, the multiparameter probe can be set to a fixed point in the water column for continuous measurement data acquisition of a specific layer.
From spring to autumn, the stratification of the water body can be determined through automated and continuous depth profile acquisition. The risk of incorrect mixing via the deep-water aeration system can be excluded in this way. Additional values for algae concentration and pH values are captured and saved with each depth profile.
- Automated generation of depth profiles or time series
- Continuous monitoring
- Up to 10 measured values from the OTT netDL can be transmitted.
Advantages
- Significantly more frequent acquisition of depth profiles in the reservoir
- Consistent data basis for subsequent analyses
- Integration of data transmission into the data center
- Continuous monitoring of TIBEAN operation
Conclusion
Previously, capturing the limnologically important depth profile always required launching a boat and creating measurement profiles manually. Through the profiler winch, the operators of the Aabach reservoir now get a much more comprehensive data picture of water quality and can adjust the operation of the newly installed TIBEAN accordingly. Such a monitoring system can also be operated on autonomously working buoys.
Additional winch specifications:
- 230V or 24V power supply
- Deployable with shore connection or autonomously on buoys
- Automatic measurement up to 8 times per day (depending on maximum measurement depth)
- Individually adjustable minimum and maximum measurement depth
- Maximum depth of the system depends on the multiparameter probe used (drum capacity 100m or optionally more)
- Individually adjustable layer height (distance between measurement points)
- Individually adjustable waiting time between measurement points
- Manually approachable depth - parking the measurement probe
- Continuous measurement at parked depth
Project-specific adaptations:
- Connection to process control system possible
- Display available on request for reading probe parameters, current system status, and control
- Presentation of measurement data in online monitoring portal
- Automatic calibration runs
- Detection of obstacles in the water body
- Automatic lake depth determination selectable
- Automatic start after power loss
- Storage of measurement data on data logger, directly in a connected database, or on the controller
- Communication technology depending on available infrastructure (fiber optic, serial interfaces & protocols, LAN, WLAN, HSPA, UMTS, or GSM)
- Remote maintenance service (firmware update, program update)
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