Building Sustainable Communities with Water Permeable Paving Materials
Two independent studies conducted by NASA have confirmed that groundwater reserves are depleting all over the world, and which can trigger a global drought in the coming decades. (https://nasasearch.nasa.gov/). From India, to China, to US and several parts of the world, groundwater usage is no longer sustainable since more water is being drained than what is replenished.
One of the reasons for this imbalance is construction techniques that did not take into consideration of the impact of climate on the landscape. The increased use of impervious asphalt and concrete for road construction, and flooring in commercial properties (paver blocks for example) cause rainwater that falls on such surfaces stagnates there and evaporates over time. Only a tiny fraction of this water can drain into the ground and recharge the water table.
BASF has developed an array of solutions that is mindful of the environment while supporting the rapid growth of urbanization. Elastopave®, for example, is an innovative paving concept which is a polyurethane top layer matrix that is water and air permeable. The surface mixture is made of pieces of rock, stone, glass or gravel to create a material that is strong, durable and cohesive. The polyurethane is designed to be water and air permeable so that water drains quickly and replenishes aquifers. The surface has many interconnected voids and has a high degree of porosity. Various absorbent ground layers below ensure that water percolates effectively. This helps channel rainwater quickly and efficiently to the water-table below. The cavities and the resulting water-permeability make it an ideal choice in paving surfaces of parks, car-parks, driveways and pavements.
The wide varieties in the raw materials used give architects and interior designers plenty of design flexibility while creating outdoor spaces. It also makes it less dependent on specific materials, which is a very sustainable approach. This, and the large degree of porosity makes it an eco-friendly alternative. The resulting ground can take in around 4,000 liters of water per hour per square meter. This enables replenishment of aquifers, prevention of puddle formation and, in the long run, a greener and cooler environment.
Apart from its aesthetics, the water and air-permeability of the material is also the reason why it is widely used in transport infrastructure, bridge, building and canals. Its usage will only increase with time to support the increasingly critical need to conserve water.
Take the case of a role model municipal project in a major China city, Hangzhou. The city was facing water logging during rainfall, which caused flooding and damage to infrastructure as well as threats to human lives. BASF helped the municipal government’s efforts to solve the issue with its climate adapting innovation. A polyurethane pave surfacing was carried out thereby absorbing and re-using at least 70% of rainwater for future use. This innovation helped transform Hangzhou into a ‘sponge city’ in its efforts towards its 2030 agenda of sustainable development.
Elastopave from BASF is an intelligent and practical approach to paving needs. It offered a sustainable solution to Hangzhou city’s water logging issue. Closer to home, as India paves way for more smart cities, urban designs focus on human spaces. Smart cities realize that the key to urban mobility is moving people, not vehicles. This means, giving priority to pavement as walking spaces as a part of the public transport solution. In Tamil Nadu, the Corporation of Chennai’s groundbreaking initiative to create high quality footpaths on the city’s major roads has shown that better designs can carve out space for broad, continuous walkways while streamlining the flow of traffic. Initiatives such as these coupled with adoption of innovative techniques and materials from BASF such as Elastopave, can give India a boost in its smart city planning and design.