Hidden beneath the bustling Avenida Juan B Justo lies the Arroyo Maldonado a secret river with a captivating history. This isn’t just any waterway. For centuries the Arroyo Maldonado shaped Buenos Aires. It served as a natural boundary before Belgrano and Flores neighborhoods joined the city. Legend speaks of La Maldonado a woman who arrived with Pedro de Mendoza in 1536. Abandoned on the stream’s edge her story became entwined with the Arroyo’s fate.
Initially a clear stream the Arroyo Maldonado transformed as the city grew. It became a polluted garbage dump. Overflowing during rains it posed a serious threat. In 1924 authorities made a bold decision. They would encase the Arroyo Maldonado in a massive underground tunnel.
The project was monumental. Hundreds of workers labored for years. They used thousands of tons of materials including rebar cement sand and gravel. The resulting drainage system is one of the city’s most impressive feats of engineering. German firm Siemens-Schuckert played a key role in its design. In 1934 a packed-earth road was built above. This road became the Avenida Juan B Justo in 1937.
Even this massive undertaking wasn’t enough. Seasonal flooding persisted affecting thousands. In 2005 Mayor Aníbal Ibarra announced additional works. Two new relief tunnels were built. These tunnels dramatically increased the system’s capacity to handle rainfall. The larger tunnel alone cost US 200 million. It used 200000 cubic meters of cement.
Today the Arroyo Maldonado remains largely unseen. Its story however lives on in the legends and the avenue that now bears its name. The Arroyo Maldonado’s journey reflects Buenos Aires’ own evolution. From a natural boundary to a symbol of urban challenges and engineering prowess it continues to shape the city’s identity. We stand above a marvel of engineering a testament to human ambition and the enduring power of a hidden waterway.