Rii Terà of Venice

The demand for expanded pedestrian pathways led to the transformation of some of Venice's canals into Rii Terà. The Rii Terà are previous canals that were filled in with rock, gravel and dirt. These newly created streets, while generally wider than the original walkways, are also situated closer to sea level, to preserve the functionality of water level doors, rendering them more susceptible to flooding. The former canals that shape the borders of islands integrated into larger landmasses add a unique historical dimension to the city. Venice, with its 126 distinct islets today, has likely witnessed the existence of double this number throughout its history as an island has been removed everytime a canal has been filled-in. The curves in Rii Terà often reflect the contours of the former canals. While around 50 filled-in canals are known, there may be more that remain undocumented. Some streets are suspected to be Rii Terà, yet their designation as such remains unconfirmed, underscoring the ongoing exploration of Venice's fascinating landscape.

Throughout the history of Venice, diverse governing bodies have held power over the allocation of rii terà. Predominantly, the Austrian government led this effort, issuing 19 rii terà spanning 3351 meters. Closely following, the Serene Republic of Venice, crucial in city governance, filled in 15 rii terà, totaling 1598 meters. Other influential entities, like the Italian government (6 rii terà at 1366 meters) and the French government (5 rii terà spanning 972 meters), also impacted the landscape with the issuing of canals to be rii terà. Additionally, joint efforts between Austrian and Venetian authorities filled 5 rii terà, covering 573 meters. These varied interventions showcase the governance's connection with the city's physical evolution over time.

The government will usually decide to fill in a canal to create a rii terà if its flow has been impeeded or stopped, interfering with the removal of wastewater. This is done in the interest of public health, as excess wastewater can contribute to sickness and disease.

Understanding that when a street is flooded at a height of 110-120cm or higher, it could signal the presence of a potential rii terà. Analyzing this flooding helps identify lower streets, offering a starting point to investigate the existence of these submerged streets, although it doesn't outright verify them as filled-in canals. To validate these discoveries, archaeological data and historical documents play a vital role, providing evidence and context that strengthen assertions about newly discovered rii terà. By combining empirical observations with historical records, a more comprehensive understanding is formed.

However, it is still possible that there are many undocumented rii terà, as they were created well before the first maps of Venice were accurately created. These possibly undocumented rii terà might make up portions of the streets in Venice.

When canals were covered, intentionally left lower than surrounding streets to preserve water level doors, it caused flooding just before nearby streets and posed a great issue. While flooding is the more precedent issue at play, other factors were altered with the inclusion of rii terà. Aesthetically, normal streets and rii terà are very different because of the change in the time period they were created. Wider buried canals, now seen as poorly paved strips in the streets, outline the buried canal's shape. However, the resulting tree-lined avenues depart from the traditional Venetian style, disrupting the city's urban layout. These walkways, unlike the Venetian aesthetic, worsen pedestrian traffic and encroach on potential water spaces, impacting water movement. The differences, like poorly paved strips and irregular widths, show the disconnect between rii terà and the city's historical aesthetic.

Rather than burying the canals in Venice, a wiser approach involves restoring Rii Terà to their original canal forms. This transformation not only betters water circulation but also streamlines boat traffic by creating new links between canals, effectively managing minor water traffic. Additionally, this concept introduces new areas for boat parking and aims to revive Venice's urban identity by removing non-traditional elements, returning to the city's authentic aesthetic. This strategy preserves Venice's historical charm while enhancing its functionality and visual aspects.

The Venice Project Center has thoroughly cataloged and located Rii Terà in Venice, employing innovative methods to detect these submerged canals. By analyzing flood levels in streets and historical maps, they precisely identified the locations of these canals and their original configurations. Their research also delved into the negative impacts of Rii Terà, proposing potential solutions. Additionally, they documented various types of Rii Terà, offering a comprehensive understanding of these submerged features in Venice's urban landscape.