Clarification note from IMPA regarding rainfall in Horto.

In light of the intense rains that hit the city, causing disruption and destruction in the Botanical Garden and Horto, false information has been circulating on social media about the land where the annex of the Institute of Pure and Applied Mathematics (IMPA) will be built. IMPA expresses its solidarity with the residents and clarifies that no trees have been removed from the property and that construction has not yet begun. All requirements of the municipal authorities to obtain the license are being rigorously followed.

Since Tuesday (9), IMPA has been in contact with the residents' associations of Jardim Botânico and residents of the affected areas near the site. IMPA teams were on site with Geo-Rio technicians and residents to assess the impact of the storm and, this Thursday (11), an expert hired by the institute inspected the site. The cleaning of sediments and pipes on the site has already begun.

The expansion project received the 2017 Recognition Award from the Lafarge Holcim Foundation in Switzerland for respecting the environment and reducing its impact on the surrounding forest and urban areas. The project includes slope stabilization and the installation of stormwater retention basins ("retention basins"), measures that will result in increased geological and hydrological security in the region. The project is supported by 25 complementary studies, including drainage and containment studies.

The unusually high rainfall in Horto (334mm in just a few hours) was a record in 22 years. The force of the water caused the complete destruction of a section of Rua Raimundo de Freitas Matos, above the IMPA grounds, creating a crater approximately 10 meters high and 25 meters long. These sediments were carried by the rain down the slope of the area towards Rua Barão de Oliveira Castro, forming a powerful waterfall mixed with debris, without passing through the IMPA grounds. Some houses on Rua Barão de Oliveira Castro were affected by this incident, which was unrelated to the institute's area.

IMPA's property was also affected by the storm, which carried sediment and blocked storm drains. In December, the institute had cleaned a retention well and the storm drain. At that time, a large amount of sediment was removed. The other drains were unobstructed until Monday.

IMPA reiterates that it is in constant contact with the associations of Horto and with the residents of the area.