<p><strong>Abstract.</strong> Flash floods in the Ondara River have caused many fatalities and damages in the town of Tàrrega in the last 400 yr. Unfortunately, no flow records are available. <br><br> However, floods can sometimes be reconstructed thanks to available historical information: limnimarks, written accounts and archaeological surveys. Indeed, from these data and using the retromodelling method on three different scenarios to take into account morphology changes, the peak flows of

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... seven greatest floods occurred in Tàrrega since the 17th century were estimated. <br><br> The results showed that the heaviest flood's specific peak flow (10.7 m³ s⁻¹ km^&amp;minus;2) ranks among the highest ever modelled or measured in similar-sized catchments in the Western Mediterranean region. The results pointed out, as well, that the changes in channel's morphology (mainly, the disappearance of a mediaeval bridge under sediment) caused by one of the floods increased the hydraulic capacity of a crucial cross-section. All this resulted in modest floods invading the town less often, but with much faster and, thus, more destructive flows. <br><br> A preliminary estimation of the results' uncertainty was 4% for great floods and 18% for modest floods. <br><br> The reconstructed peak flows will be introduced in a database for a future use in climatic and hydrological studies.</p>