Flood and Landslide Checks in Brazil

Why a clean title tells you nothing about risk

A matrícula, the property's registry record, tells you who owns the land and what liens sit on it. It says nothing about the hillside above or the canal behind. You can do every search in the title guide and still buy a house inside a mapped landslide sector. So these checks sit alongside the legal ones, and no one in a normal sale will do them for you.

Federal law gives you a place to start. Law 12.608/2012 tells every municipality to identify and map disaster-risk areas, to block new occupation there and to inspect risky buildings, evacuating people where needed (art. 8, IV, V and VII). A 2023 amendment, Law 14.750, added real-time monitoring of high-risk areas and early warnings by siren or phone message (art. 8, V-A and V-B). Municipalities with areas prone to landslides or sudden floods also go on a national register and must map those areas and adopt contingency plans under art. 3-A of Law 12.340/2010. Where people already occupy such areas, art. 3-B allows removal after a technical report.

The disasters of the last few years shape what follows. Recent events in Porto Alegre, Petrópolis, Recife, São Sebastião and Maceió each hit a different kind of ground, and each one has its own tool or office. Salvador's concern is spread across many mapped slopes. Each city has a chapter below.

Money follows risk, too. In Maceió, some insurers stopped renewing policies around the subsidence area, and homes without insurance could not get bank financing. A property you can't insure or finance is hard to resell at any price. Check this before you fall for a view on the listings page, and before you plan your resale, as covered in the guide to selling as a foreigner.

SGB risk sectors

The Serviço Geológico do Brasil, or SGB, was long known as CPRM, and older reports carry that name. Since 2011 it has mapped risk areas with municipal civil protection offices. It covered 821 municipalities between 2011 and 2014, kept updating them and added others. Its state-by-state page now shows 1,817.

Each study draws sectors of high and very high risk, and only where people live or spend time in buildings. The scale is detailed, 1:1,000 to 1:2,000. Teams assess terrain, signs of slope movement, past events, how vulnerable the buildings are and, for water, how close occupation sits to drainage channels. The hazards covered are floods, flash floods, landslides, rock falls and debris flows.

Read the limits carefully, because SGB itself sets them. The maps don't replace slope stability studies or engineering projects. They don't rate whether a retaining wall works. They don't predict when something will happen, or how far debris will travel. Low and medium risk are left out on purpose, and empty land isn't mapped at all. So "not in a sector" can mean lower risk, vacant land or a place the survey never reached. A new development on bare land could be outside for that last reason.

How to use it

1. Open the page of products by state and click your state.
2. Find the municipality and open the latest year. The link goes to RIGeo.
3. Download the package. SGB says each study holds risk maps, a technical report and vector files.
4. Match it to your address using street names and landmarks. If a sector touches your block, ask an engineer.

Being absent from the list means nothing

Some of the country's best-known risk places are not listed by SGB. State or municipal bodies may hold the mapping for those places. Don't read absence as safety.

A report from 2012 is old. A river can shift, a slope can be cut and a street can be built after the map. Use the date as part of your reading.

Susceptibility, hazard and suitability maps

Risk sectors are the most detailed SGB product, but they only answer one question. SGB's disaster-prevention page lists others, and they help most where a sector study has nothing to say, such as bare land or a new subdivision.

Use them from wide to narrow. Start with susceptibility to see the broad picture: a valley floor or steep slope will show up. Then look for a hazard map, which adds the path of the material. A house below a slope can sit in the path even if the house's own lot looks apartment. Finish with the risk sector if one exists.

The viewer is SGB's Mapa de Prevenção de Desastres on its geoportal. It is a web map application, so use a desktop browser. If it won't load, use the state pages, which link to the documents. The scale of 1:50,000 means a line on the map covers tens of meters on the ground, so never use a susceptibility map to judge one lot. It tells you to ask more questions.

Land buyers have an extra legal test. Law 6.766/1979, art. 3, sole paragraph bars subdivision on flood-prone land until drainage is secured, on slopes of 30% or more unless the authorities set specific conditions, and on land whose geology doesn't support building. Art. 12, §3 bars approval of subdivisions in risk areas that the master plan marks as non-buildable. A lot sold outside those rules has both a physical and a legal problem. That kind of informal sale is covered in the guide to posse and escritura, and rural land has its own guide on foreign buyers and rural limits.

What to ask the Defesa Civil

The municipal Defesa Civil, or civil protection office, holds what the national maps don't: incident logs, evacuation orders, recent inspections and local mapping. Its name varies. Salvador's is Codesal. Ask in writing, because a written answer can go into your file and into a dispute later.

Give the full address, the registry number if you have it, and coordinates from a map app. Then ask:

• Is this address in or next to a mapped risk area, and what is the grade?
• Which document and year is that based on?
• Has any incident, inspection, interdiction or evacuation been recorded here or on this street?
• Is the area covered by sirens or alert messages?
• Has any retaining wall or drainage work been built nearby, and who maintains it?
• Can an inspector visit, and is there a fee?

Not every office will answer quickly, and a small town may have one officer. A lawyer's letter can help. Your local lawyer can also ask the city's urban planning department whether the master plan restricts the lot, and the buying guide shows where those requests fit in the timetable.

A word on what an answer means. "No record" is what the office knows, and an office may have started keeping records a few years ago. A flood mark on a neighbor's wall outranks a blank file. Treat the reply as one piece of evidence and pair it with the walk-around below.

On the ground

Ask about the last big rain from people with no stake in the sale. Look at lower walls for stain lines, and at repainted strips that stop at the same height. Look for leaning posts and fences, cracks that widen toward one corner, and drains full of silt. In a building, go down to the garage, pump room and electrical room. Read the minutes from the rainy months for repairs. A flood repair may have been funded by a levy, explained in the condominium fees guide. On an example of 60 units, a R$ 600,000 pump and electrical rebuild would cost R$ 10,000 per unit (about US$ 1,845).

Porto Alegre and the 2024 flood

In May 2024 the Guaíba reached 5.33 m on the night of 6 May, as CNN Brasil reported from the data then available. The flood level is 3 m. The previous record was the 1941 flood at 4.76 m. On 10 May, the neighborhoods still reported as affected included Serraria, Guarujá, Ipanema, Tristeza, Vila Assunção, Cristal, Praia de Belas, Menino Deus, Floresta, Navegantes, Farrapos, Anchieta, São Geraldo, Sarandi and the Centro Histórico.

The five Porto Alegre neighborhoods this site covers, Moinhos de Vento, Bela Vista, Petrópolis, Mont'Serrat and Auxiliadora, were not on that one-day list. A press list from one day clears nothing, so check street by street, especially in lower-lying blocks.

Tools

• The city's flood map from May 2024, published by its ObservaPOA office, shows the mapped flood across the city.
• The flood database from researchers at UFRGS, the federal university, holds the flood extent on 6 May 2024 from satellite images, with depth estimates, a simulation at 5.50 m at the Cais Mauá gauge and a severity map. It is free under CC BY 4.0. The authors warn that the data is a work in progress, that depth estimates carry uncertainty and that field checking isn't finished.
• The Institute of Hydraulic Research at UFRGS built an interactive map with scenarios at 4.76 m, 5 m and 6 m, assuming no walls, dikes or pumps. That makes it a test of what happens when defenses fail.
• SGB's three Porto Alegre studies, from 2013, 2018 and 2022, remain useful for slopes and sectors, though they predate the 2024 event.

Water doesn't always sit apartment. One UFRGS group noted that wind and runoff can make a difference of up to a meter between the south and north of the city. So don't compare your ground floor with the gauge figure to the centimeter. Use the observed extent first and the level second.

Then ask two building questions. Did water reach the garage or pump room in 2024, and what was repaired and at what cost? And does the building depend on a street-level or basement electrical room? Gramado and Canela, up in the hills, face different ground, so use the Gramado page for local context and SGB's state list for slope studies there.

Petrópolis

On 15 February 2022, a month's expected rain fell on Petrópolis in about six hours. Poder360 gives 233 deaths, and other counts run slightly higher. Morro da Oficina, in Alto da Serra, was the worst hit. A year later, containment and drainage work there had started only in January 2023, in three stages.

Five weeks after the first disaster, on 20 March 2022, the city recorded 534.4 mm of rain in 24 hours and 250 landslides across 19 localities. The city named Alto da Serra, Bingen, Castelânea, Centro, Chácara Flora, Duarte da Silveira, Estrada da Saudade, Independência, Morin, Mosela, Quissamã, Quitandinha, Saldanha Marinho, São Sebastião, Siméria, Valparaíso and Vila Militar. So the list includes the center as well as hillside districts. Officials also pointed to structural problems in the Túnel Extravasor, a flood tunnel, as worsening flooding in the center, which means an address in the apartment center needs a flood question and a hillside address needs a slide question.

Petrópolis is not on SGB's Rio de Janeiro page, which lists only Angra dos Reis, Cantagalo, Nova Friburgo, Santa Maria Madalena and Sumidouro. So your first stop is the city's Defesa Civil. Ask for the risk mapping that applies to the address, for its date, and for any record from the 2022 events. If you are buying a weekend house in a condominium in the hills, ask who maintains the slopes and roads, since that is a levy question as well as a safety one.

Recife and Jardim Monte Verde

The rains of late May 2022 killed 128 people in Pernambuco by the count reported on 3 June. Folha de Pernambuco puts 48 of those deaths in Jardim Monte Verde, a hillside community on the border of Recife and Jaboatão dos Guararapes, in the Ibura area.

Since then, the state has been building a R$ 58 million slope project there, reported as 60% done in May 2025, and a local Defesa Civil base was set up there. Recife's city hall reports 24 finished containment works in Ibura since 2021, worth R$ 36.8 million. Repair of canal walls in the area was designed, and awaited a budget at that time.

The lesson for a buyer in the wider metro area comes in two parts. First, the worst site was a hillside community, well away from the beach buildings. Second, flat ground has its own question. Rain and canals can cut streets and fill garages even where no slope exists, so Boa Viagem, Casa Forte and Espinheiro buyers should still ask how the street behaved in May 2022.

Recife does not appear on SGB's Pernambuco page, while neighboring Olinda, Jaboatão and Ipojuca do. Go to the Defesa Civil do Recife, which states that it monitors risk areas on a permanent basis, and ask for the sector maps it holds. If you are looking at Olinda, its hills are worth a separate look at SGB's report for the municipality.

Salvador's slopes

The risk debate in Salvador centers on its encostas, the slopes. Codesal, the city's civil protection office, mapped 171 risk areas between 2016 and April 2024, according to Bahia Notícias. Another figure quoted in the 2024 election campaign was 164 localities, 14 of them critical. The two numbers come from different documents, so ask which list applies. The incumbent mayor's plan reported 132 containment works done or under way between 2021 and 2024, with 56 more being designed. It also promised to finish a risk-classification system known as Sicres.

Salvador isn't on SGB's Bahia page. Nearby Lauro de Freitas (2012, 2019) and Camaçari (2023) are. Your route is Codesal itself. It publishes annual reports and rain-season material, and it can tell you whether a site has a recorded incident.

Don't assume an address on the beach road in Barra, Ondina or Rio Vermelho, or on the bay side in Corredor da Vitória, is clear of this. Look behind the building as well as in front of it. Ask for a stability report on any retaining wall the condominium owns, and read the budget for its upkeep. Geomantas, the erosion mats seen on many slopes, and containment walls are signs that someone has acted. They are no proof that the work is sufficient, which is exactly what SGB says its maps can't judge.

São Sebastião and the São Paulo coast

On the night of 18 to 19 February 2023, about 680 mm of rain fell on the north coast of São Paulo in a day. In São Sebastião 64 people died, and Ubatuba recorded one more death. One report names Barra do Sahy as the worst-hit neighborhood, and the warnings below name Vila Sahy.

The warning signs were on paper. Brasil de Fato counted at least four warnings over ten years: a 2013 Unicamp study, a 2018 survey by the state's Institute for Technological Research listing 52 landslide-risk areas, a 2020 finding by state prosecutors that called Vila Sahy a tragedy foretold, and a 2022 state housing proposal to move families out. So the risk was documented years before the disaster.

São Sebastião, Ilhabela and Guarujá do not appear on SGB's São Paulo page. Ask the city's Defesa Civil, then ask for the state-level mapping it uses. A beach house on flat sand can still lose its road access, so ask about the routes in and out as well as the lot. For a house near the foot of a slope, note its distance from the base of the hill and ask an engineer.

Maceió ground subsidence

Maceió has a hazard that no rainfall map shows. Tremors in the Pinheiro neighborhood in March 2018 led to official studies, which found that rock-salt mining at mines run by Braskem had caused progressive sinking of the ground in five neighborhoods: Pinheiro, Mutange, Bebedouro, Bom Parto and Farol. Federal prosecutors put the direct impact at over 14,000 properties and about 60,000 people moved. In late 2023 the ground above Mine 18 in Mutange sank by 1.69 m in days, and the civil protection office warned of a possible crater. The agreements that followed require monitoring of the cavities for at least ten years.

How to check an address

• Find the latest version of the city's Mapa de Linhas de Ações Prioritárias, the priority-action map. Version 5, published on 30 November 2023 with the national Defesa Civil and the federal university of Pernambuco, widened the relocation area and included Bom Parto. The city calls the map dynamic and not final, so ask the Defesa Civil whether a later version exists.
• Ask about the monitoring area as well as the relocation area. Version 4, for example, added 1,417 lots to monitoring, including parts of Bebedouro and Farol.
• Ask for the latest report of the technical monitoring committee. Its 2026 campaign visited 2,216 homes in nearby areas and fully inspected 704, looking for cracks that might relate to the sinking. Its report was due at the end of July 2026.
• SGB's Maceió reports date from 2012 and 2017, so they do not cover this problem well.

Insurance and loans reach further than the map

Press reports in 2024 said insurers applied a 1 km safety margin around the risk area, reaching Canaã, Chã da Jaqueira, Chã de Bebedouro, Farol, Feitosa, Gruta de Lourdes, Jardim Petrópolis, Levada, Petrópolis, Pitanguinha and Santo Amaro. Some policies weren't renewed, and without insurance no bank financing was available. The law here is unsettled: a federal appeals court held in May 2023 that insurers needn't cover homes within the margin, and in January 2024 a federal court declared illegal the margin set by Caixa, the federal savings bank. So get a quote and a lender's written position for the exact address.

The beach neighborhoods

A 2024 study led by researchers at the Federal University of Alagoas ranked neighborhoods by vulnerability to the subsidence. It placed Bebedouro, Bom Parto, Farol, Gruta de Lourdes, Mutange, Pinheiro, Ponta Grossa and Vergel do Lago as most vulnerable. Cruz das Almas ranked low. Jatiúca, Mangabeiras, Pajuçara and Ponta Verde were left unclassified, which means the researchers could not assign them a level. The study weighs economic, social and environmental factors too, so it isn't a ground-movement map. Being unclassified is no finding of safety, so use the official map for each address, and ask a seller directly about their insurer.

What to do with the answer

If the checks come back clean, keep the papers. They help at resale, and they show you acted with care.

If they come back mixed, you have four options: walk away, ask for an engineer's report and then decide, cut the offer to reflect the cost of protection works, or buy on a condition. Only you can weigh that, and the guide to buying from an owner explains how conditions work in a direct sale.

A seller's declaration

The Civil Code gives limited help after the fact. Arts. 441 and 442 let a buyer reject a property or claim a price cut for a hidden defect that makes it unfit or reduces its value. Art. 445 sets the window for real estate at one year from delivery. For a defect that can only be found later, the year runs from discovery, with a limit of one year. Art. 446 asks you to report the defect within 30 days where a warranty applies. Whether a flood history counts as a hidden defect depends on the facts, and a lawyer has to judge that. Art. 422 adds a general duty of good faith.

So don't depend on a later lawsuit. Ask the seller to sign a declaration listing any flood, slide, crack, evacuation or interdiction they know of. A seller who won't sign has given you an answer. The same goes for a broker's vague assurance, and the brokerage directory is a place to find someone to ask the local question.

Sellers should do this too. Listing through the free listing page with the Defesa Civil reply attached answers the buyer's first question before it is asked.

Questions

Sources

1. Serviço Geológico do Brasil, risk area mapping explained
2. Serviço Geológico do Brasil, disaster prevention products and scales
3. Serviço Geológico do Brasil, risk products by state, 1,817 municipalities
4. Serviço Geológico do Brasil, Rio Grande do Sul page, Porto Alegre products
5. Serviço Geológico do Brasil, Rio de Janeiro state page
6. Serviço Geológico do Brasil, São Paulo state page
7. Serviço Geológico do Brasil, Bahia state page
8. Serviço Geológico do Brasil, Pernambuco state page
9. Serviço Geológico do Brasil, Alagoas state page
10. Planalto, Law 12.608/2012 on civil protection, with Law 14.750/2023
11. Planalto, Law 6.766/1979 on land subdivision
12. Planalto, Civil Code arts. 422 and 441 to 446
13. CNN Brasil, Guaíba levels and affected neighborhoods, 10 May 2024
14. UFRGS group, Guaíba flood database, May 2024, on Zenodo
15. IPH UFRGS, flood map of Porto Alegre
16. UFRGS Gespla, maps of historic floods in Porto Alegre
17. Prefeitura de Porto Alegre, flood map, May 2024
18. Poder360, Petrópolis one year later, February 2023
19. Agência Brasil, 250 landslides in Petrópolis in 24 hours, March 2022
20. Folha de Pernambuco, Jardim Monte Verde three years on, May 2025
21. Notícias ao Minuto, final count of Pernambuco's 2022 rains
22. Bahia Notícias, Salvador risk areas and containment works, October 2024
23. Brasil de Fato, warnings to São Sebastião, February 2023
24. Diário do Nordeste, 65 deaths on the São Paulo coast, February 2023
25. Ministério Público Federal, the institutional response in Maceió, March 2026
26. Prefeitura de Maceió, version 5 of the risk map, November 2023
27. Prefeitura de Maceió, version 4 of the priority-action map, December 2020
28. Prefeitura de Maceió, committee inspections, May 2026
29. Agência Brasil, Mine 18 subsidence figures, December 2023
30. Notícias do Centro, insurers and the 1 km margin in Maceió, May 2024
31. UFAL, study of neighborhood vulnerability to subsidence, July 2024