El Viar Dams In Southern Spain:
Embracing Expansive Clay

Alfonso Perez (Inside Infrastructure Pty Ltd)

Dam Construction Using Expansive Clay,<br>Case Study of two dams built in Southern Spain in 2007-2008


The use of expansive clay in road construction and dry embankments is well established thanks to traditional soil stabilisation methods. However there is relatively little experience in the use of expansive clay for the construction of large earth dams and water retaining structures.

El Viar irrigation dams were built in southern Spain in the period 2007-2008. With a combined water storage volume of 4.3 GL and a total earth fill volume of 2.7 M m3, the two dams deliver flows to more than 13,000 ha of irrigation land near Seville. Geotechnical investigations carried out by the contractor during the early stages of construction identified high expansive clays in the majority of the dam basins. The discovery motivated a series of changes in the dam design to include the expansive clay as the main construction material within the dam body.


The presentation will explore the key elements of the two dams, the geotechnical characteristics of the construction materials and the changes to the original design aiming to integrate the expansive clays.

About Alfonso PerezAlfonzo_Perez

Alfonso Perez is a Chartered Engineer by the Institute of Civil Engineers in UK and holds a Master Degree in Civil Engineering by the Polytechnic University of Madrid, Spain. Member of the Australian Water Association and the International Committee of Large Dams, most of his professional experience can be related to dam and water retaining structures design and construction in several countries, including Spain, Portugal, France, US, Puerto Rico and Chile.

His previous experience includes working for Hydraulic Research Wallingford and Wessex Water in UK and the main contractor Dragados in Spain. He now works for the Adelaide based consultancy Inside Infrastructure, providing professional services across the water engineering and geotechnical spaces.

In 2009 Alfonso was awarded Spain’s Young Engineer of the Year.

Engineers Australia members participating in AGS technical sessions can record attendance on their personal CPD logs. Members should refer to Engineers Australia CPD policy for details on CPD types, requirements and auditing guidelines.