Abstract. — The urban district of Lyon makes use of two aquifers, namely the fluvioglacial alluvium and, especially, the holocene plain of the Rhône river. This water-catchment is located upstream Lyon in the islands of the river and can provide 1 Mm3 per day of an excellent water ; it supplies drinking-water and part of the industrial water, the complement being pumped by the plants themselves from the aquifers of from the river. The polluted waste-waters, in spite of the construction of filtering stations, are thrown off downstream Lyon and damage strongly the quality of the running waters.Résumé. — L'agglomération lyonnaise dispose de deux aquifères, la nappe des alluvions fluvio-glaciaires et surtout la plaine holocène du Rhône. Les cap...