Water Tech at the Expo

by Nathan Bennett

The Beijing International Horticultural Exhibition（hereinafter “Beijing Expo”） is showcasing technology supporting its theme， “Live Green， Live Better.” Technological advancements not only make life more convenient but also facilitate greater harmony with nature. We rely on nature for many things， but like roommates living together in the same apartment， we can make it easier for each other to get along. While electricity， wireless connectivity， and 5G make for easy touchpoints in a discussion of technology， what about water management？

A good point to begin with is the difference between science and technology. Science is the systematic study and accumulation of knowledge about life， the universe， and everything. Technology is the implementation of that knowledge to make things and do things. Science studies the speed of light， and technology turns on the light. Electricity and WiFi make for easy demonstrations of technology because they represent the closest approach we can make to real magic in this world， but technology to manage water purification， storage and utilization comes much closer to vital human needs than 5G.

While 5G is revolutionizing communication， it operates on a level not directly catering to basic human needs. Water management does. Accordingly， water management technology is prominent among the technologies being tried out at the Beijing Expo.

Water management technology includes construction methods and the employment of specially chosen plants for water retention and pollutant filtration， so water management especially works out the integration of human construction and nature. Including both active and passive methods， the technology displayed at the Beijing Expo exemplifies the forward thinking required to achieve integration with nature.

Running out of water is not the only problem for water management technology to deal with： the July 2012 flooding in Beijing gave the city a very personal motivation to implement appropriate water management technologies. Overwhelmed drainage systems do not lead only to flooded industries， businesses， and homes and damaged human interests. Urban water runoff is already somewhat polluted， but flood waters overleaping the normal bounds of stormwater drainage carry extra pollutants into the rivers where runoff eventually goes.

While typical water issues for Beijing include increased demand for water resources in an already dry northern China， climate change means larger storms with more rain all at once. No one likes to drink from a fire hose， and not even a dry city benefits from a flood. Aside from water issues facing Beijing， traditionally wet and rainy southern China needs all the modern drainage technology that it can get because urbanization pressure leads developers to pave over the natural features that formerly mitigated flooding. Smart development requires integration with nature， not just shoving it aside or cutting it out altogether.

The centerpiece of the Beijing Expo is the China Pavilion. Like many of the buildings featured at the expo， the China Pavilion features roof rainwater capture and subterranean storage capacities. Outdoor wooden plank walkways feature water drainage gaps to collect rainwater for watering the terraces bracing the sides of the building. The terraces themselves insulate the China Pavilion from cold and heat， reducing the need for extra watering in hot times of the year. Reducing the extremes of hot and cold also moderates energy requirements for heating and cooling.

Nature requires an array of cycles and processes to maintain and replenish the resources human society draws upon. Where rainwater collection reduces the amount of rain that can replenish groundwater supplies taken up for irrigation， human society demands availability of water for tangible， appreciable use. In integrating with nature， intelligent application of ecological technology can introduce an element of efficiency into the progression of water toward its final resting place in aquifers or the sea.

The China Pavilion is a proof of concept for the use of rainwater for on-the-spot beautification of urban architecture. The terraces insulating the sides of the pavilion are watered with the rainwater collected from the roof and as the water makes its way to its final resting place in the natural cycle， it gives life to the plants beautifying the pavilion. In cities， rainwater that washes off concrete and glass tower blocks could be retained in like fashion to green up otherwise bleak cities.

The International Pavilion features a forest of shade umbrellas which double as rainwater collectors， showing one of the most important principles of innovation and task unification in a single feature. This intuitively implemented technique， ubiquitous in the park， clearly demonstrates how clear forward thinking can improve city management of resources and the aggregate proceeds of rooftop water collectors can contribute to a citys water efficiency.

Water management technology is a very traditional part of ancient societies. The India Pavilion offers a model of stepwells found in that country， showing how since ancient times water was made available in times of drought. Stepwells connected to surrounding reservoirs and groundwater， and series of steps facilitated access down to the current level of water. By turning to their own ancient cultures， nations can find internal motivation to implement water management technology.

Two aspects of water management are the retention and the purification of water resources. It is not enough simply to hold the water in storage tanks， and getting the most use out of water resources involves retaining it for urban environmental benefit and human enjoyment. Maintaining trees along the roads or watering city parks sustains natural environments for city-dwelling animals and provides natural scenery for people to enjoy. As water passes through plants and soils， various contaminants are filtered out.

The Grant Associates rain garden is one practical example of gardens constructed to manage and purify urban runoff. By contributing a habitat for animal life， the rain garden reveals the potential for integrated water management schemes to enrich urban environments. A sustainable， low-maintenance urban forest provides greenery while gradually releasing accumulated storm runoff to ease weather impact on city drainage systems. The International Bamboo and Rattan Organization（INBAR） contributed a garden demonstrating the value of bamboo and rattan to improve soil conditions， reduce water runoff， and provide economically valuable products from plant life integrated into water management plans.

Many needs intersect in water management： human thirst， urban drainage， industrial and agricultural usage， animal and plant life， and others. The increasing world population allows little margin for inefficiency in water usage， and natural processes cannot keep pace with the construction of cities and towns. Pandas cant decree it， dolphins cant organize it， and trees cant weigh in at all. Humanity will have to arrange it from beginning to end.

The array of water management technologies on display at the Beijing Expo provide a catalogue of options for city planners and developers worldwide to consider as they manage water usage， whether they are flooded or drying out. In a time of stability， before we hit emergency conditions， the world can come together at the Beijing Expo to plan how to manage increasingly limited water resources for the future so that we can face times of greater environmental strain with confidence.