Flood ocurrence in the Consuegra (Toledo) region has been studied according to historical records and hydrometereplogical methods based on rainfall data. The Amarguillo river, upstream from Consuegra, has a flow around 109 m3/seg. for 100 years, which represents almost half of the total flow (235 m3/seg. for 100 years). Main floods occur in the upper basin, where Consuegra Is located, related to larger slopes but less Infiltration capacity. Adjusting these results to the catastrophic flood that ocurred in 1891, it has been estimed to have a recurrence period of 100 years. The disastrous effect o f this flood can therefore be justified by the channel constriction by buildings, rather than to other external causes like an ancient roman dam break, upstream from Consuegra