San Andrés Detention

The San Andrés Dam, built between 1759 and 1804, is one of the major hydraulic control structures of the Northern Branch of the Pisuerga Canal. Measuring 110 meters long and 5.80 meters high, it stands directly in the Pisuerga Riverbed, where it retains and diverts the water necessary to supply the canal. Its structure, built entirely of sandstone ashlar, reflects the solidity and precision characteristic of Enlightenment engineering. Attached to the dam are the intake gates of the Pisuerga Canal, a newly constructed infrastructure that continues the historical function of regulating the flow. The entire complex is well-preserved, and its comprehensive protection underscores the heritage value of a structure that has maintained its essential function for over two centuries.

Very close to the dam is the associated house, also built between 1759 and 1804. Rectangular in plan and single-story, it combines living quarters, a courtyard, and a stable under a gabled roof. Its brick walls with surrounds and moldings, along with the wooden structure and ceramic tiles, demonstrate a functional architecture adapted to the continuous maintenance of the dam. Although its state of preservation is not good, it retains original facades and structural elements, giving it considerable environmental value within the complex.

A visit to the San Andrés Dam is an ideal place to understand how the Canal de Castilla interacts with the territory and how these discreet but essential works have sustained its operation since the 18th century.