Following a history of severe floods, the government decided to develop a defense plan to minimise future flood damage.
The Plan Sur was the most expensive and colossal of three alternatives, and involved digging a new route from the outskirts of Quart de Poblet to northern Pinedo, crossing through the Huerta de Valencia.
The work started in 1963, and was not completed until 1969.
From the start of the project it was decreed that all letters and parcels that were sent from Valencia would have to bear an additional stamp worth 25 centimo, to offset the costs and this continued until as late as 1985.
