 The work began on 28 November 1607, and was terminated by 13 May 1609.Corrosion and the constant action of the water caused caving-in in the interior of the tunnel, and obstructed the passage to such an extent that, during the viceregency of Archbishop Fray García Guerra (1611–12), in reply to the inquiry made by Philip III for information concerning the utility of the work, the amount so far expended, and what would still be required to complete it, the archbishop and the municipal government replied that the work done by Martínez was not sufficient to place the city beyond the danger of inundations and that $413,325 had been expended and 1,126,650 workmen engaged in the work.Martínez wrote to the king contradicting this information.