We must start from the existing regulations on flood risk. One difficulty that hinders the adoption of specific measures in the face of flood risk is the dispersion of competences held by the different public administrations at different levels, be it the local administration, which draws up urban development plans for municipalities and civil protection plans (emergency plans); the regional administration, which has competences in spatial planning, civil protection and management of the public water domain and, finally, at state level, the central administration, which also has competences in civil protection and management of the public water domain in intra-community basins. It would be necessary to urgently unify these dispersed regulations, reinforcing the regulatory framework and unifying the current dispersion of competences between the different administrations. 

In the specific case of the Valencian Community, areas at risk of flooding (in relation to land use planning) are regulated in the Territorial Action Plan for Flood Risk in the Valencian Community (PATRICOVA) approved in 2003 and revised in 2015.
This plan is binding for all urban planning instruments (urban development plans) or territorial planning, but does not have a retroactive application, i.e. plans prior to its entry into force in 2003 do not include the PATRICOVA determinations.In the Valencian Community we have a high percentage of obsolete but valid plans, known as the petrification of planning, which means that they are not adapted to PATRICOVA. For this reason, it is necessary to create an obligation to adapt all these plans to this territorial action plan, taking on board its precepts.

On the other hand, it is also necessary to reflect on anthropic change and flood risk. It is a reality that the risk of flooding, which is a natural risk, has been increased by the urban occupation of risk areas with buildings (legal or illegal) and/or infrastructures in flood-prone areas.This situation increases the natural danger and can even be considered a high risk of catastrophe such as the one we have experienced this past week.When there are episodes of moderate intensity rainfall, DANA, understood as a natural phenomenon, the riverbeds (ravines, streams, etc., which are normally dry) regain their functionality, transforming these urbanised areas into high-risk areas as they have been occupied by humans without taking into account their designation as flood zones. These new constructions aggravate potential flooding due to the pressure they exert on the natural land adjacent to the banks of watercourses, preventing the free flow of water and forming dams that aggravate the risk of flooding.

The risk to the structural stability of buildings increases considerably when water has eroded the foundation. This occurs if there has been a flow of water that has worn away the soil under the foundation, creating a gap that could cause settlement, leading to cracks or even partial collapse of the building. In buildings with load-bearing walls, such settlement would cause cracks in the walls, forming discharge arches or, in severe cases, the collapse of the wall.

Another possible situation is that water at high velocity impacts on the facades, which may cause the facades to collapse and, consequently, the building to collapse to a large extent. When water infiltrates through walls or in case of flooding, the damage affects installations, cladding and finishes. It is essential to have these elements checked by a professional installer before putting them back into operation. In the case of finishes, the damage is mainly aesthetic and, before applying the final paint, it is necessary to clean the surface and wait for it to dry.

The assessment of the damage should be carried out by professionals with building-related qualifications, such as architects or technical architects, who are the best people to assess the urgency of the interventions, especially if the fire brigade has not previously acted ex officio.