Interaction between dams, valves, and pipes

The interaction of industrial valves, dams, and the associated pipelines forms an indispensable basis for modern water management and energy supply. Coordinated interaction between these components is crucial for the efficient use of water resources, ensuring their long-term availability, and at the same time guaranteeing the necessary safety in all operating conditions.

Dams act as artificially created reservoirs that can hold large quantities of water and release it again as needed. They fulfil numerous tasks: from supplying drinking water and irrigating agricultural land to generating electricity from hydropower. Technical elements are indispensable for precisely controlling this water cycle. Fittings such as sluices, valves, and throttling devices play a key role in this process. They ensure that outflows are regulated, flooding is prevented, and water is directed to the desired locations.

However, fittings alone are not sufficient: only in combination with an extensive network of pipes can their full functionality be realized. These pipes transport the water from the dam to consumers, power plants, agricultural irrigation systems, or back into natural watercourses. In doing so, they must withstand high pressures, resist corrosion, and adapt flexibly to changing operating loads. High-performance pipes made of steel, cast iron, or modern composite materials are now designed to operate reliably for decades. In many cases, they also act as safety buffers by absorbing sudden pressure surges and thus relieving the connected fittings.

The complex interplay of dams, valves, and pipelines illustrates how closely modern infrastructures are interlinked. These systems are an expression of engineering expertise that not only makes natural resources usable, but also sustainable. They ensure a stable water supply, secure energy production, and at the same time protect people and the environment from the risks of extreme weather events.

The Schwarzenbach Dam in the northern Black Forest has been in operation since 1926. (Source: Wikimedia/Dpesek)

One dam per 1,000 square kilometres

There are currently 371 so-called “large dams” in Germany according to the current definition. These are characterized by barrier structures with a height of over 15 meters or a total volume of more than 1 million cubic meters. Alternatively, they are also listed in the World Register of Dams (ICOLD), although different thresholds apply internationally in some cases – there, the classification “large” begins at a capacity of 3 million cubic meters. Converted, this means that there is an average of one dam per 1,000 square kilometres.

Of the 371 dams in Germany, 231 serve several purposes. They are used for flood protection, hydropower generation, agricultural irrigation, fishing, supplying shipping routes, and tourism. In addition, they supply raw water, drinking water, and cooling water, and are playing an increasingly important role in stabilizing water levels during dry periods. To perform these diverse tasks, a finely tuned network of pipes is required to drain or distribute the water in controlled quantities. Especially in times of climate change, it is clear how important this infrastructure is for compensating for low water phases and maintaining security of supply.

Dams can be opened to reduce the risk of flooding. (Source: Saxony State Dam Administration)

Many dams are multipurpose facilities

Dams play a key role in flood protection and water supply. At the same time, they help to ensure that rivers and streams maintain a minimum water level during dry periods. The increasing weather extremes in Germany—caused by climate change—are significantly exacerbating the need for these functions. Without dams, many rivers would have already dried up during hot summers.

A review of the 2021 floods shows that in North Rhine-Westphalia and Rhineland-Palatinate, most of the dams, which are operated there as multi-purpose facilities, were able to partially fulfil their protective function. Even though they were originally built primarily for raw water supply, they contributed significantly to mitigating the catastrophic consequences of the floods. The dam itself was not the only decisive factor here; the system of pipes that ensured controlled drainage was equally important. Without intact pipes to drain the water masses in an orderly manner, the disaster would have been far more devastating.

The events also made it clear that precise control of the discharge is only possible if fittings and pipes are in top condition and are regularly modernized. Old pipes pose a risk because they could break or fail to withstand the water pressure in an emergency. This highlights the need for continuous investment in technical infrastructure.

The floods in North Rhine-Westphalia and Rhineland-Palatinate caused billions of dollars in damage in 2021. (Source: AdobeStock/Christian)

Challenges posed by climate change

The flood disaster revealed two different types of hazards: unregulated rivers, which swelled into raging torrents within a very short time, and regulated dams, whose storage capacity was not adjusted in time. In both cases, the question of how much water could flow through pipes and fittings played a decisive role.

The central challenge for the future is therefore: How can dams be controlled under changing climatic conditions? Weather conditions such as the stationary “Central European low” lead to continuous precipitation throughout entire river basins for days on end. Studies by the German Weather Service show that these weather conditions could occur about 20 percent more frequently by 2100. For dam operators, this means that they must develop new concepts in close cooperation with meteorologists and regulatory authorities.

This also brings the question of the resilience of the connected pipe systems to the fore. They must be able to reliably handle both enormous amounts of water during heavy rainfall and low flow rates during dry periods. Flexible and durable pipelines are therefore just as crucial as the masonry of the dams themselves.

At the Pirk dam in Saxony's Vogtland district, the historic valves were replaced with new ring piston valves in 2023. (Source: Saxony State Dam Administration)

Outlook: Adapting to new realities

There are more than 370 dams in Germany, many of which are in low mountain ranges and will be particularly affected by extreme precipitation in the future. Studies predict an increase in these events across a broad belt stretching from North Rhine-Westphalia to Rhineland-Palatinate and Hesse to Bavaria. Adapting dam management to climate change is therefore a task that affects at least five federal states.

However, many of those responsible have so far tended to rely on isolated solutions. For example, the state government of North Rhine-Westphalia announced that it would only review existing concepts based on the experiences of 2021. There is currently no cross-state strategy. In addition, dam supervision has been severely depleted in terms of personnel in recent decades. Only now, as climate change and extreme weather conditions increase the pressure, is it becoming apparent how urgently capacities need to be built up.

The operators themselves also face a dilemma: on the one hand, they want to stick to proven operating models, but on the other hand, climate change is forcing them to invest in more modern systems. In addition to innovative fittings, this also includes resilient pipelines that function reliably over the long term. Only if the interaction between dams, fittings, and pipes is consistently developed further can the security of supply in Germany be guaranteed in the coming decades.