This is a design studio focuses on the urban ecology.
Th design is a new urban water park, of which the site is in the center of Shenzhen, where there is a lake of 0.5 sqkm. The lake was a reservoir at 1960s, and then developed into a water theme park in 1980s, and finally abandoned in the 1990s. The lake is surrounded by a lot of villas and residence now, and has been polluted for over 25 years. Only a few citizens now know this lake. On the other hand, most of the fish here are tilapias, a kind of fish imported from Africa in the 1970s, which was seen as an important source for protein. But it also got urbanized and is called “rubbish fish” now, as they eat everything, even rubbish. And some fishing man now often don’t take them home, but throw them back to the lake or just sell them back to the manager of the lake, and most of the fish in the lake are bought from markets, which are originally cultivated in other cities.
So, I’m wondering if the lake can be recovered as a better habitat for the fish, and also a wonderful attractive space for human. Precisely speaking, the lake is being passively polluted, and is just physically located in the urban. What I’m trying to do is to help it to participate in the whole urban system, to purify the wastewater, to help treat the huge storm water, to take advantages of the polluted water, to cultivate fish in a healthy water condition.
As you can see, most of the wastewater is from a mixture of rainwater and domestic wastewater, and the others are from the golf court, restaurants, and the surrounding residences. So, initially, I’m trying to design a system to help purify both of the mixed rain water and the daily domestic waste water. The system is constituted of two parts: one is a chemical & physical sub-system, and the other biological. As the residential area is 5 meters higher than the lake area, so I designed some terraces and some tanks below them to place the chemical and physical system. Typically, the water will be pre-treated in these tanks and then pass through the constructed wetland, thus the biological system, and finally, arrived at the lake. As for the tanks, only a few of them will be occupied by the chemical-physical system, and the rest will be used for feeding fish. Particularly, the heavy rain only happens several times each year, and when it happens, some tanks will be replaced by the huge amount of polluted water temporally, and which will then get pretreated , and flow into the lake through the wetland. When the water is gone, those tanks will be occupied by fish again. So, that means there will be two mechanisms for the daily sewage water and the mixed rainwater. By doing this, it will guarantee the mixed rain water will not flow into the lake directly like what it does now, and the water for fish will not be influenced.
And let’s talk more about the fish cultivation here. I’m keeping thinking about what the polluting water and the mixed rain water can bring us except troubles. Look at the typical price and amount variation of tilapias in a year, the farms can only cultivate once in a year, as the fish cannot stand a water temperature lower than 10 degree. Most of the time, the fish has the lowest price at June, July and August, as many farms sell the fish at that time, not only because the fish nearly grow up at those months, but because they will be easily infected in high temperature. Those three months are also the rain season for Shenzhen. So when it rains, the rain water replaced some tanks of fish, and the fish flow into the low-lying space and the ponds I designed on the grassland, and some into the lake. This will help to lower the density of fish in a high temperature, and also make it attractive for people to come here for fishing, catching fish or swimming, just because there are healthy fish, clean water and space designed for these events. When the water is gone, the space can be used as exits of subway, or open space for dancing and gathering. From March to September, the fish mainly live in the lake and the tanks, but from October to January, most of them are cultivated in the tanks, as there’s a higher temperature with the help of concrete walls, glass covers and the heat offered by the waste water. So the contractor can cultivate twice a year, and sell them at a higher price in the next year.
So, after all, it’s not only solving the water problems, but to establish a system to help it make contribution to the city: the urban waste water and mixture rain water now will not pollute the lake any more, but help to fasten the circulation of the lake, to cultivate healthy fish, to keep fish warm in winter, help people to enjoy the water as a new real water theme park, and help us to understand the urban and nature more.