Fontaine de Nimes karst system (France)

Multi-tracer investigations and modelling revealed the structure and preferential flow paths of the Fontaine de Nîmes karst system. The research demonstrated how groundwater storage can initially attenuate rainfall-runoff, but how aquifer saturation and rapid conduit flow can subsequently amplify flash-flood response. These findings led to a hydrogeological forecasting approach for karst floods.

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Location: the city of Nimes, Occitanie region, France

Elevation: 55 - 120 m a.s.l.

Geology: Cretaceous limestone

Aquifer type: karst aquifer

Scientific question: " What is the role of groundwater during floods "

The Fontaine de Nimes system is part of SNO Karst and the OZCAR research infrastructure

Location map

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Key findings

Karst catchment and groundwater flow: hydrogeological investigations and multi-tracer experiments defined the structure and recharge area of the Fontaine de Nîmes system and identified preferential underground flow paths.
Groundwater contribution to flash floods: the 2005 events showed that the karst system can rapidly transmit newly infiltrated rainfall to the spring. After an initial rainfall event saturates the aquifer, its remaining storage capacity decreases, increasing runoff and flood response during a subsequent storm.
Karst as both buffer and flood amplifier: the aquifer can initially store and attenuate part of the rainfall, but once highly saturated, rapid conduit flow and limited storage can contribute to very rapid flooding.
Hydrogeological modelling for flood forecasting: a conceptual and numerical model of the karst response to rainfall was developed and used to create a practical forecasting approach for karst flash floods in Nîmes.

Hydrogeological model

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Picture gallery

[Gallery picture]

Scientific collaborations

BRGM team: N. Dörfliger, B. Ladouche, V. Bailly-Comte, JB. Charlier, P. Fleury, N. Courtois
Associations spéléologique Nîmoise (ASN) team: G. Jouanen
SNO Karst network

Related publications

Quantifying water origin of a Mediterranean urban karst aquifer using storm event typology and high-frequency physicochemical signatures

Jean-Baptiste Charlier, Vincent Bailly-Comte, Bernard Ladouche, Jean-Christophe Maréchal

Hydrogeology Journal, 2026 Oct

SNO KARST : A French Network of Observatories for the Multidisciplinary Study of Critical Zone Processes in Karst Watersheds and Aquifers

H. Jourde, N. Massei, N. Mazzilli, S. Binet, C. Batiot-Guilhe, D. Labat, M. Steinmann, V. Bailly-Comte, J.L. Seidel, B. Arfib, J.B. Charlier, V. Guinot, A. Jardani, M. Fournier, M. Aliouache, M. Babic, C. Bertrand, P. Brunet, J.F. Boyer, J.P. Bricquet, T. Camboulive, S.D. Carrière, H. Celle-Jeanton, K. Chalikakis, N. Chen, C. Cholet, V. Clauzon, L. Dal Soglio, C. Danquigny, C. Défargue, S. Denimal, C. Emblanch, F. Hernandez, M. Gillon, A. Gutierrez, L. Hidalgo Sanchez, M. Hery, N. Houillon, A. Johannet, J. Jouves, N. Jozja, B. Ladouche, V. Leonardi, G. Lorette, C. Loup, P. Marchand, V. de Montety, R. Muller, C. Ollivier, V. Sivelle, R. Lastennet, N. Lecoq, Jean-Christophe Maréchal, L. Perotin, J. Perrin, M.A. Petre, N. Peyraube, S. Pistre, V. Plagnes, A. Probst, J.L. Probst, R. Simler, V. Stefani, D. Valdes-Lao, S. Viseur, X. Wang

Vadose Zone Journal, vol. 17, Soil Science Society of America, 2018, p. 180094

Karst flash-flood forecasting in the city of Nimes (southern France)

Perrine Fleury, Jean-Christophe Maréchal, Bernard Ladouche

Engineering Geology, vol. 164, 2013 Sep, pp. 26--35

Karst flash flooding in a Mediterranean karst, the example of Fontaine de Nimes

Jean-Christophe Maréchal, Bernard Ladouche, Nathalie Dorfliger

Engineering Geology, vol. 99, 2008, pp. 138--146

Version française - système karstique de Fontaine de Nîmes