FYSEG in the XI Spanish Conference on Dams

FYSEG has participated in the XI Spanish Conference on Dams with the presentation of three works made within the scope of the Biscarrués Dam Design, the remodeling of the spillway of El Atance dam and the study of the bottom outlet and the stilling pool of Pálmaces dam.


This dam is situated in Huesca and it has been supervised and carried out by ACUAES. It is located over the Gállego River and its main goal is to control the level of floods and to provide flows to the Riegos del Alto Aragón irrigation system to increase the system quality.

The dam has been designed with hardfill, an unprecedented typology in Spain, and was selected after a comprehensive study of alternatives which takes into account the aspects related to the foundation issues, available materials, structural safety, implementation of new hydraulic elements, economic aspects and, of course, the environmental advantages.

The designed dam has a maximum height of 56 m over foundation, a total material volume of 330.000 m3 of hardfill. The spillway is situated over the central part of the dam and is made of 6 openings regulated by gates of circular sector, 11 x 5.37 m.

Biscarrués dam: Download Biscarrues poster


El Atance dam regulates the waters of the Salado river, tributary of the Henares river, in Guadalajara. It is a gravity dam with a straight base and it has a spillway over the body of the dam. It started to be built in 1996, using a vibrant roller-compacted dry concrete.

The profile of the dam in the spillway is Bradley type and was designed for a water depth of 1.5 m which corresponded to a 500 years flood. Part of this profile and discharge channel is set in a staggered way, taking advantage of the method of construction used.

The Hydraulic Laboratory, CEDEX, carries out a small-scale test model of the spillway to verify the hydraulic performance since the design of the staggered transition between its threshold and the discharge channel does not respond to any previous verified pattern.

In the small-scale test model, two solutions are studied: the first one is maintaining the water depth of the project and the second one with a depth of 2.35 m, resulting from applying the current legislation. This allows to propose the remodeling of the dam’s profile in the spillway, establishing a staggered transition.

El Atance dam: Download Atance poster


The Pálmaces dam is gravity type with straight base and more than 30 m high over its course. It is located over the Cañamares river, tributary of the Henares river, in the province of Guadalajara.

The stilling pool which, at the bottom of the dam, is fed by the flow rate of the intermediate and bottom outlet presents an anomalous behavior respecting the spill of the bottom outlet. The drained water impacts the closing of the stilling pool producing an inappropriate water rising effect for the preservation of the structure.

In order to analyze this effect and find a solution which improves the hydraulic behavior of the existing infrastructure, a numerical modelling and a small-scale test model of the dam’s bottom outlet and the stilling pool are carried out.

The interaction between both models results positive, taking advantage of the results of each one of them and studying a wider range of solutions. The test in physical model allows to observe complex phenomena to be modelled, as well as measure the numerical model. This model allows to check several alternative geometries and establish solutions that, after their previous approval, can be tested in the physical model.

Pálmaces dam: Download Palmaces poster