The Arroyo Mayor Aqueduct, built between 1831 and 1836, is part of the Campos Branch of the Canal de Castilla, designed to overcome major watercourses. Located in the municipality of Paredes de Nava (Palencia), at kilometer 108.270, its main function is to allow passage under the Arroyo Mayor channel, also known as the Retortillo River, while simultaneously ensuring the control and regulation of its flow.
The structure comprises three segmental arches, a lowered arch type that reduces the height of the structure without compromising its stability. The entire structure reaches a length of approximately 20.70 meters and a height of nearly 6.40 meters. It is built entirely of limestone ashlar and is completed with lateral wing walls and parapets that flare out at their ends in a quarter-circle shape. Beneath the channel are cantilevered walkways, currently constructed of concrete. On the left bank, at the entrance to the aqueduct, an intake with a regulating gate is preserved, feeding a small channel which drains into a stilling basin on the Retortillo River. Downstream, a concrete divider cuts across the channel basin and serves as an intermediate support between two regulating gates, while the foundation and the channel itself have been reconstructed in concrete.
For the visitor, the Arroyo Mayor Aqueduct offers a particularly revealing experience, allowing them to understand the technical complexity of the Canal de Castilla in contact with an important river course, enjoy the riverside landscape and observe how engineering, water and territory are articulated in a work designed to last.
