In all stages of industrial water treatment (underground pumping, surface and underground processes, water processing, wastewater treatment), humidity causes issues that can threaten the safety and availability of public drinking water. These issues include: 

  • Condensation on cold surfaces such as pipes and other equipment
  • Corrosion that can damage structures, equipment, pipes or control systems 
  • Mould and bacterial growth resulting in health risks for staff and compliance issues 

  • Interrupted and unreliable service for customers

  • Increased costs for maintenance, operations and energy consumption 


Condensation, including its resulting issues and expenses, is one of the largest practical challenges in the water supply industry. Condensation creates the ideal conditions for all types of microbial and bacterial growth and for corrosion to occur. Standard Cotes units provide dehumidification technology that efficiently operates at the lower temperatures usually found in water supply facilities. They are effective across a temperature range of -15 to 35°C. The right dehumidification strategy provides customised solutions for large-scale humidity management without the need for additional ventilation installations or expensive specialised ducting.


The original reservoir on Speicherstrasse in the St. Gallen region, Switzerland, was built in 1881 with a capacity of 550m3 and was gradually expanded to a capacity of 5600m3 before it was demolished because it was not watertight enough. A new reservoir and pump station with most of the construction volume underground and a total capacity of 7600m3 was built in 2016 in the original location. 

Aerial view of St. Gallen reservoir Image: Aerial photo of St. Gallen

Not only does the reservoir supply water to the city of St. Gallen, but it can also deliver fresh drinking water as far as Hamburg, Germany. In addition to supplying drinking water, the reservoir is used as a water reserve for the local fire service and has a sensor and alert system in case the water level goes below a certain point.

The drinking water chambers must meet very high-quality standards for durability, tightness, hygiene and surface smoothness inside the reservoir. Targeted decisions about material use and functionality have been to extend the lifetime of the reservoir. Problems caused by humidity, such as mould, bacterial growth and corrosion could get in the way of meeting necessary strict standards and high quality. It is essential for the St. Gallen reservoir to control humidity in the drinking water chambers to provide safe drinking water and protect the health of the public.

The right dry-air solutions help ensure optimal conditions in reservoirs for water quality and safety. That is why the reservoir and pumping station in St. Gallen has been equipped with a Cotes adsorption dehumidifier – installed by the Swizz company Krüger + Co. AG, a Cotes partner.

Reservoir and pumping station planImage: Plan of reservoir and pump station in St. Gallen with Cotes dehumidifier in the red circle


Krüger chose the Cotes CR450 for the St. Gallen Reservoir and Pump Station because its capacity and effective performance at low temperatures suited the plant's requirements. Despite being installed some years ago, the dehumidifier is in perfect shape and still does its job very precisely, ensuring a mould-free and corrosion-free environment without needing to be upgraded to a newer model.

Cotes visiting reservoir and pump station in Switzerland


Dehumidifier in reservoir St. Gallen


Image: Cotes visit to the reservoir and pump station
in St. Gallen, Switzerland
Image: Cotes dehumidifier CR450 in the
reservoir and pump station in St. Gallen


For waterworks projects, a model from the C-range would normally be used. Adsorption dehumidifiers from this range are designed to fit the specific requirements of any waterworks facility and can be customised with add-on modular parts. Learn more about the C-range of Cotes adsorption dehumidifiers: Download the Datasheet


  • Better end-to-end control of air conditions  
  • Condensation control which reduces corrosion in and around structures, fittings and equipment 
  • Reliable, uninterrupted services for meeting your customers’ needs 
  • Significant savings in energy consumption, operating costs and maintenance expenses 
  • Compliance with hygiene standards 
  • Improved health and safety conditions for staff 
  • Reliable solutions providing exceptional return on investment 


Cotes adsorption dehumidifiers allow you to carefully control the dew point of the air, preventing the unwanted consequences of condensation. This reduces the need for traditional anti-condensation measures such as heating and ventilation, that are expensive and often ineffective. Cotes adsorption dehumidifiers are well suited to the water supply industry, their well-thought-out design enables many possibilities for usage and transportation. 

Preventing humidity allows for proper control and maintenance of sanitation standards, eliminating potential challenges with compliance and cross-contamination. Cotes standard units work effectively at the lower temperatures often found in waterworks systems. In addition, Cotes adsorption dehumidifiers are equipped with incredibly dependable fans that create a slight overpressure in the surrounding air. This eliminates the need for expensive-specialised ductwork or additional ventilation systems, ultimately delivering controlled-humidity air to all areas of your waterworks.


20210622 Adsorption dehumidifiers line upImage: Cotes Adsorption dehumidifiers


Do you have issues with humidity? 

Tell us about your problems with humidity in your waterworks, or business, and we will connect you with one of our experts who will recommend the right dry-air solution for you.