170 years of Canal de Isabel II: El Villar and innovation in dams

Of the many dams that Canal de Isabel II manages or has managed throughout its 170-year history, the El Villar dam does not tend to spring spontaneously to the minds of people. The El Atazar and Pontón de la Oliva dams are probably better-known and enjoy the greatest popular recognition, the former because it is the largest of the existing dams, and the latter because it was the first to be built, back in the times of Isabella II. The Pontón de la Oliva dam has now been in disuse for over a century.

Because it is in the shadow of other dams, the El Villar dam – and its history – possibly slips under the radar more nowadays, despite the fact that it was a true civil engineering milestone at the time. Moreover, it is the oldest dam currently in service operated by Canal de Isabel II.

The El Villar dam

This decisively important water infrastructure for Madrid dates back to more than a century and a half ago, to 1858, when the waters of the Lozoya River, stored in the Pontón de la Oliva reservoir, were conveyed to Madrid for the first time to alleviate the supply problems afflicting the capital.

The construction of the Pontón de la Oliva dam was of vital importance at the time and has gone down in the annals of Spanish hydraulic engineering history. However, the dam had a short service life due to the leaks that affected one of the reservoir slopes. Over the years, engineers and workers made constructive adjustments to minimise water losses and keep the infrastructure operational, but the difficulties associated with sealing the leaks were clear. It was evident that a new reservoir would have to be built to enable the shortcomings of the original reservoir to be forgotten. And the solution was the El Villar reservoir.

Located on the lower course of the Lozoya River, the El Villar reservoir provided the real solution to the problem of water supply to Madrid following the failure of the Pontón de la Oliva reservoir. The El Villar dam, the oldest operating dam in the Autonomous Community of Madrid, was the highest dam in Spain at the time.

The proposal of Morer and Boix: An arch dam ahead of its time

Engineer José Morer, who had designed the water supply network in Madrid, was placed in charge of the operations to design and obtain the budget to build a dam to retain the meltwater so that it could be used in summer. Hydraulic engineer Elzeario Boix worked hand-in-hand with Morer. Together they travelled along the course of the Lozoya in search of the best site for the new Canal de Isabel II infrastructure, which they located 22 km upstream from the Pontón de la Oliva dam.

Following analysis of the terrain, the two engineers were convinced. The slopes on either side of the riverbed and the bed itself were formed by extremely hard gneissic rocks, which offered the security and impermeability they sought.

With the help and supervision of Morer, Boix designed a dam which, in terms of conception, type and construction, would become the true masterpiece in the system that supplied water to Madrid in the 19th century.

Boix was attracted by the concept of the arch dam and decided to apply this design to El Villar. This curvature, together with the concavity of the downstream face, were two of the main successes that made El Villar an infrastructure ahead of its time. It created a precedent for vaulted dams.

He proposed that the intake gates be operated from a central tower attached to the upstream face, an distinguishing feature that still gives the dam its own personality.

The completion of the works in 1882 made El Villar the highest dam in Spain

The body of the dam was built with masonry and concrete made of Zumaya cement, with ashlar cladding and ashlar finishes. Moreover, the rapid raising of the wall meant that it was not necessary to wait for it to be fully completed before it came into partial operation. It did so in the summer of 1873, by which time it had already formed a small reservoir of one cubic hectometre.

The works were fully completed in 1882. By then, with a height of 50 metres and a crest of 107 metres, El Villar was not only the highest dam in Spain, but one of the highest in Europe and amongst the most advanced in terms of design. Most importantly, it retained the waters of the Lozoya River in a reservoir with a capacity of 22 cubic hectometres, thus mitigating the problems associated with supplying water to Madrid.

Since that moment, without much popularity or media attention, the El Villar dam has remained unchanged with the passing of time. It has stoically withstood more than a century and today, almost 140 years after its construction, it continues to collect the crystalline water drunk by the people of Madrid. Canal de Isabel II has been taking care of this water for 170 years, water that enjoys a well-deserved reputation, thanks to its purity, quality and flavour. There is a reason why 96% of the inhabitants of the Autonomous Community of Madrid prefer to drink their water, i.e., tap water from Madrid.

Innovations of today in the dams of yesteryear

The fact that the El Villar dam is still in service after so many years has much to do with the excellence of its construction, but also with the technological innovations implemented by Canal de Isabel II in the monitoring and maintenance of its large infrastructures. El Villar and the other 12 dams managed by the publicly-owned company in the Autonomous Community of Madrid undergo meticulous, state-of-the-art control that enables them to comply with the highest safety standards.

These infrastructures undergo permanent inspection and auscultation. For this purpose, they are equipped with a multitude of sensors and measuring instruments that allow instant diagnosis of the status of each dam. To provide an idea of the sophistication of these systems, Canal de Isabel II collects around 175,000 data every year at up to 2,700 measuring points at the El Atazar dam, and this data is analysed on a daily basis. The type of data collected includes the temperature of the concrete, the level of the reservoir, millimetric displacements, etc.

Moreover, for many decades now, Canal de Isabel II has been using predictive models of different types to estimate the ideal behaviour of each dam. These are mainly based on the temperature and the amount of water in the reservoir at a given time, although other variables are also taken into account.

And now, the publicly-owned company that operates under the auspices of the Autonomous Community of Madrid, is also using artificial intelligence to reinforce the maintenance and management of these infrastructures. Neural networks, Bayesian networks and decision trees are modern tools that enable the normal operating range of a dam to be defined with great precision. Moreover, they also serve to provide detailed information on the complex interdependent relationships of the different elements of a dam.

The construction of El Villar was a project ahead of its time and Canal de Isabel II has consolidated innovation as an intrinsic part of its history. That is why nowadays, artificial intelligence and even satellite images are contemporary cutting-edge resources implemented in line with the company’s tradition. They are the innovations of today that are keeping the dams of yesterday alive, innovations that will enable these dams to last for at least another 170 years.

Canal, towards a green future in the Autonomous Community of Madrid

Quality, sustainability and innovation have been the pillars of Canal de Isabel II throughout its 170-year history and, of course, this will continue to be the case in the future. Sustainability translates into a green economy of resources, applied to good water use in the case of Canal de Isabel II. Canal de Isabel II is a leading company that seeks efficient use of resources such as water, competitiveness in the water sector and innovation in new treatment and energy generation processes, using water as a source. Ultimately, the company is seeking to achieve environmental profitability.

Throughout these 170 years, this publicly-owned company that belongs to the Autonomous Community of Madrid has evolved in order to address environmental challenges with a view to creating a more sustainable region. This has been the case since the construction of the Pontón de la Oliva dam right through to the new projects it is now undertaking. These projects are aligned with the Sustainable Development Goals and are underpinned by a commitment to the environment.

Canal de Isabel II promotes energy efficiency and green energy through the development of projects linked to solar energy and green hydrogen. The company is to build a pioneering green hydrogen power plant in Spain (green hydrogen is a key element in decarbonisation), which will also be the first facility to use renewable energy and purified water to generate hydrogen. The construction of this plant will require an estimated investment of €24.5 million and the facility will have an installed capacity of 5 MW.

Another key project is the Solar Plan, through which the company’s own photovoltaic installations for self-consumption of electricity will be put into operation. €33 million will be invested in this project for the purpose of obtaining renewable energy and reducing greenhouse gas emissions.

According to a recent analysis conducted by credit rating agency Ficht in the utilities sector, ten Spanish companies are amongst the world’s 100 leading companies in terms of sustainability. Along with Iberdrola, Naturgy and Enagás, to name but a few, Canal de Isabel II features on this list due to its management of the integrated urban water cycle, and projects such as the Solar Plan and the green hydrogen power plant, which seek to drive the green sustainable economy in the region of Madrid.