Project data
Client
Melnick even
Project
Grand Park Eucalyptus
Local
Porto Alegre – RS
Area
3,120 m² of Tec Garden®
2,395 m² raised floor in external circulation areas
Solutions Used
Tec Garden® + Outdoor Raised Floor
Project data
Client
Melnick even
Project
Grand Park Eucalyptus
Local
Porto Alegre – RS
Area
3,120 m² of Tec Garden®
2,395 m² raised floor in external circulation areas
Solutions Used
Tec Garden® + Outdoor Raised Floor
Like other Brazilian cities, Porto Alegre is in a constant increase of urbanization. And this increase is proportional to the increase in soil impermeability, that is, the more the city grows, the more impermeable the soil becomes. One of the biggest consequences of this is the disruption of the natural water cycle, which causes water to flow superficially when it should be absorbed by the soil, increasing its volume in cities, hence drainage systems and the time it takes. to return to the urban network in the rains are compromised and the amount of flooding increases.
The figures below compare the evolution of the soil sealing process and the infiltration water reduction between the Natural Environment and Urban Environment and as we can observe the natural soil provides up to 90% infiltration and 10% surface water runoff, while, With urbanization, the soil provides 1% infiltration and 99% runoff.
The traditional solution to this problem, urban drainage, causes water to drain downstream as quickly as possible, raising the level of flooding in the city’s river basins.
In order to remedy this situation, Porto Alegre City Hall has implemented two Plans: the Urban Drainage Master Plan (PDDrU), which adopts a series of measures to mitigate the effects of flooding, and the Environmental Urban Development Master Plan (PDDUA). ), which allows the city to demand flow control measures in new projects implemented in the city.
In PDDUA, Decree No. 15,371 (November 17, 2006) regulates the control of urban drainage and, in land larger than 600m2, requires the use of storage devices in the new buildings implemented.
One such device is the rainwater holding reservoir, also called the holding basin. This device holds rainwater for a period of time to reduce downstream and rainwater flow. With its multiplication, the return time of the water will increase and the flow will be at levels acceptable to the public network. In this way the flood risks will be mitigated.
Components used in the system
Soil sealing in urban areas has a direct impact on the environment as it reduces the characteristics of biodiversity, causing degradation of flora and fauna, rising temperatures, desertification and hydrogeological changes. Therefore, vegetated areas play a fundamental role in urban areas, with which they can achieve environmental balance. Also, reducing the amount of these areas makes it difficult to retain and filter rainwater, deteriorates air quality and generates an increase in urban temperature, culminating in the “heat islands”, as we can see in the graph below.
The Project used the Outdoor Raised Floor system under the tennis and multi-sport courts, making it possible to reserve 145,900 liters of water under them.
The architectural project proposed that there were 648 underground parking spaces, which complied with legal requirements and valued the free and uncovered ground floor space for the establishment of leisure and landscaping.
The challenge of the venture was to design a large volume rainwater holding reservoir, which had a low impact on both the deployment areas and the free ground areas. And do so according to the various constraints that limited technical solutions.
One of these constraints was the height restriction in the region, instituted by PDDrU, which reduced the number of floors. This led to the adjusted use of high ceilings in underground and ground floors.
Also, in front of the property, the public sewage system had restrictions of location and depth, due to the passage of the large diameter water mains of the Deus Deus (located on Rua Barão de Guaíba, next to the Church of Menino Deus) , it was small.
These water mains brought water from the Guaíba River to the hydraulics through four pipelines with diameters greater than one meter (which surrounded the development on Silveiro and Barão de Guaíba Streets).
This limited the outflow quotas of rainwater sewers over the water mains, and prevented the use of reservoirs that were buried under the parking lot floor.
In order to achieve the proposed objective, an appropriate technical solution was sought that should be available on the market and could enable a large holding reservoir (with the least possible impact). This, given the restrictions imposed by technical and environmental constraints.
Such solution was the use of a laminar reservoir under the free areas structured by the raised floor of the ground floor, in order to compose the raised floor rainwater detention reservoir system integrated with the ascension irrigation reservoir.
The system uses the source control principle with source retention, which reduces investment in water transport and increases investment in quality retention.
The result of this system is the creation of a holding reservoir with a capacity of 314.00 m³ and a permanent irrigation water reservoir with a capacity of 344.30 m³, making a total capacity of 658.30 m³.
The laminar holding reservoir is arranged in eight basins located under the raised ground floor Remaster floor, each with a 10 cm high water depth. During rain, water that accumulates on the project’s surface is trapped in the water slides and drains to the exit point (due to gravity). This increases the return time to the public network and helps to prevent flooding at the lowest point of the block (located on the corner of Silveiro and Barão de Guaíba streets).
Floor plan of detention reservoirs
This solution also made possible the reuse of rainwater for irrigation of garden areas, as the system used requires the distribution of water in two 10 cm high blades. Of these, one is permanently full and corresponds to the irrigation reserve, and another has an empty space that is only filled when it rains and corresponds to the holding reservoir. Thus, there is an integrated system of reservoir for rainwater detention and reuse of irrigation water.
At the Grand Park Eucaliptos project, the system implementation costs proved to be viable by offsetting the costs for the construction of detention reservoirs of over 300.00 m³, possibly in concrete, including construction, excavation, waterproofing and installation of the reservoirs.
The system has numerous quantitative and qualitative benefits that can be seen at environmental, economic and social levels, making Remaster solutions one of the best options in the market today.
The system proves to be viable for projects in which there is a large area of implementation of the building, which generates large impermeable areas.
Large free areas on slabs are ideal situations for the application of the system, as the benefit of water containment, garden irrigation and viability of vegetated areas becomes evident.
The raised floor stormwater reservoir system integrated with the ascension irrigation reservoir is being implemented at the Grand Park Eucaliptos project and is an extremely viable solution from an environmental, economic and social point of view.
The main benefits it adds to society are the mitigation of the risk of flooding, the reduction of drinking water consumption (reusing rainwater for irrigation), the viability of vegetated areas on waterproof slabs and the restoration of urban biodiversity.
Melnick Even, as an institution, seeks to contribute to the preservation of the environment through economically viable technical solutions so as not to compromise future generations.