The Nadrid bridge was not demolished or dismantled; it was simply drowned, left in place as the River Lee rose around it following the construction of the Lee Valley Hydro-electric Scheme.

An ESB photograph taken in 1948, just a few years before submersion, recorded what the bridge looked like from the upstream side: at least nine semicircular arches, graduating upward in size toward the centre span, with pointed breakwaters, the angled stone piers designed to split the current and protect the bridge's foundations, rising to the full height of the structure. The overall effect would have been substantial, closer in appearance to the surviving Inishcarra Bridge nearby than to any modest rural crossing. When the ESB's hydro-electric scheme flooded the Lee Valley in 1956, the bridge was bypassed by a modern replacement constructed to the east, and the original was abandoned to the reservoir rather than cleared. It now belongs to a small category of submerged infrastructure, structures that were not destroyed so much as set aside by the twentieth century's appetite for power generation.

At certain water levels, particularly during dry summers when reservoir levels drop, the upper portions of submerged structures in managed lakes occasionally re-emerge. Whether the Nadrid bridge's arches ever break the surface in this way is not well documented, but the replacement bridge to the east offers a vantage point over the water above the old crossing's approximate location.