100 Resilient Cities (100RC), pioneered by the Rockefeller Foundation, is an organization that aims to help cities become more resilient to the social, economic and physical challenges that they have to face. Every year the 100RC select a group of cities among those that have taken part in the challenge. The chosen ones are then entitled to receive funding and the technical support – a Chief Resilience Officer (CRO) to be hired – in order to build urban resilience.

On December 2013, Mexico City was one of the selected cities by the 100RC. Measures to stregthen a metropolitan area of 21 million people are huge. Like in many other megacities around the world, informal settlements are mushrooming on the outskirts of the city, exacerbating its vulnerability to shocks and natural hazards. In particular, as a result of being built on an ancient lake, its ground soil tends to be soft and to amplify seismic waves when an earthquake occurs.

Over the years, the way Mexico City has coped with natural disasters – in particular earthquakes – has highlighted the city's strengths and weaknesses that should be taken into account when attempting to increase the city's resilience.

1985 Earthquake

On September 19th and 21st 1985 a magnitude 8,1 earthquake hit Mexico City leaving some 250,000 people homeless and 900,000 with damaged houses while also affecting nearly 1,700 schools and reducing by 1/3 the city's hospital capacity. Despite being prone to earthquakes, the city was bad prepared to face this extreme hazard resulting in overcrowded low-income housing in need of repair to be the worst affected. However, response to the disaster was immediate and effective.

When the earthquake struck, Mexico's economy was facing a tough time. Following the debt crisis of 1982, the Government was imposing fiscal austerity and didn't show any policy change in the aftermath of the disaster, refusing to cut foreign debt payments to use the money to help with the recovery effort. It also didn't want to request international aid in order to avoid increasing the national debt.

Mexican citizens, who were witnessing their institutions prioritizing political and social control over recovery measurements, took active response by rescuing victims and providing food and shelter. Emerging civil society groups helped empower community participation while putting pressure on the governement and this resulted in a Presidential decree that created the Renovacion Habitacional Popular (RHP), an agency set up for housing reconstruction and temporary shelter supervision that focused its attention to low-income housing called "vecindades". Financed by FONHAPO (Low-Income Housing Fund) and the World Bank, the RHP managed to rebuild some 44,000 dwellings in the span of two years.

After almost three months of survey and the introduction of a new building code, the RHP established to demolish and rebuild all tenements in danger of collapse and to repair those in need even when damages hadn't been caused by the earthquake. However, given the decision to add private bathrooms and kitchens to the affected housing together with the aim of reinforcing non-damaged parts in order to avoid building collapses in the future, the majority of tenants were given completely refurbished apartments because it was economically more convenient. Furthermore, contrary to early proposals for reconstruction on some areas close to the airport, affected families got their new homes onsite and were temporary accomodated on shelters close to their residences.

In the end, the reconstruction process turned out to be an opportunity for low-income families to upgrade their living standards. In fact, thanks to the Expropriation Decree, the city governement first owned the affected lands, and then renew and sold the refurbished houses to the people who were living there before the earthquake while paying a compensation to the former owners.

The role of participation is a key issue in the successful reconstruction after the 1985 earthquake. Earthquake victims eligible for benefits took part to regular meetings to review program plans, to approve them and to finally sign documents for the construction of their apartments. Once an agreement was reached, beneficiaries legally became part of a condominium association that worked as "renovation councils" where people could speak out. Individual needs were then discussed with the RHP through the elected representatives of each association. The whole process was supported by different types of civil society groups that worked with the victims such as political parties, university groups, technical support groups, voluntary individuals and religious organizations. Usually, each site saw the presence of at least two of the above mentioned groups.

Thirty years on

Three decades after the successful recovery of 1985, earthquake safety and preparedness levels in Mexico City are still low as if lessons hadn't been learned. Improvements in terms of monitoring systems and emergency response have been mainly limited to the city centre where the earthquake had hit the most. Moreover, following the reconstruction stage, private investments have intensified over the years. Government policies, like "Bando Dos" that incentivates growth in the city centre, have further contributed to raise property prices forcing low-income citizens to sell their houses and move to the periphery that has kept expanding, regardless of compliance with building regulations applied elsewhere.

Irregular settlements
It is often reported that irregular settlements in the capital constitute roughly half of the constructions and are home to almost 60% of the whole population. Their illegal status is often due to various causes such as unauthorised land development, lack of building permit, exposure to environmental hazards (i.e. landslide, floodings, etc).

In their early stages, the formation of informal settlements was neither limited nor controlled but often ignored. Over the years, the illegal condition has evolved turning some settlements into fully or partially regularised ones. This was the direct consequence of a context where rules were not universally applied and individual rights such as land tenure or infrastructure were guaranteed by allegiance to leaders who could negotiate with the authorities in exchange for consensus. Usually citizens were able to receive electricity provision and later on other services through various forms of municipal finances showing some sort of recongnition of these settlements. Among the benefits, there was regularisation.

As far as the building process is concerned, usually it is characterized by a lack of credit. Depending on the amount of money a family can muster, the construction is financed in stages and this represents the only solution affordable by the majority of the population. Besides, the urbanisation process of an area is also incremented starting from land occupation, followed by electricity provision, water drainage, infrastructure improvements.

Some can argue that, despite the questionable management, irregular settlements might bring social benefits allowing low or middle income families with housing and infrastructure. However, they also represent a social cost due to their impact on the environment. In particular, their location on the hillsides represents a block for natural drainage channels leading to an increase in floodings and landslides; while those built down the valley, below the water, contribute to rise the cost for drainage provision.

Building regulatory system
Mexico does not have a national building code and the majority of efforts on this fields have always been focused on Mexico City. As a consequence, today the Mexico City Building Code (MCBC) is basically a model often applied in others municipalities of the country. The first MCBC was issued in 1942 and it has since been updated approximately every ten years by a coordinated team of academics and practitioners. Due to the country exposure to earthquakes, requirements for seismic design are subject to constant update, especially after the 1985 earthquake. Nevertheless, improvements in building codes have not corresponded to an increase in the construction knowledge of local practitioners. This had led to a lack of compliance with construction codes due to misunderstandings and inability to correctly apply regulations.

There is a sensible difference between the expertise of a small, well-qualified group of practitioners and academics and the vast majority of professionals. As a consequence, for seismic regulations to be properly applied, it is important to organize them following different levels of complexity with important structures being subject to the most complex approaches and more simple ones to be applied on most common structures of limited size.

Building code is important, but if its applicability is not guaranteed, then it's useless. At the same time, governments should focus on property prices and low-income housing policies in order to avoid the proliferation of informal settlements. In emergency situations, Mexican citizens have proven the ability to react, mobilise and improve their poor conditions. Resilience in Mexico City should strongly consider participation of its residents while trying to raise new common issues able to gather communitites under a common goal to be reached.