INTERVIEW

Landscape Record Vol. 1/2015.02120

Landscape Record (LR): Clean, potable water is becoming scarce in many places. What do you think a landscape architect can do about this?

Tao: It is true that clean water is becoming scarce in many parts of the world, but we also need to be reminded that water is 100% recycled in and around the earth, not one ounce less, not one ounce more. Every drop of water on earth today has existed for millions and millions of years. At one point, it could be the vapor exhaled by a dinosaur; yet at another point it becomes a drop of clean water in our tap. Whether it is usable for us human beings today depends on how we treat water. If we disrespectfully mix water with all the toxic substances and discharge it to the rivers carelessly, then we are reducing our own available water source.

It is difficult to dissociate my profession from my whole being as an environmentally conscious

Water as a Resource and Inspiration of My Design

Tao plays dual roles of a landscape

architect and an ecologist at Sasaki. He

believes that good landscape architects

are scientifically informed artists who

compose shared spaces that both offer

transcendent outdoor experiences and help

maintain healthy ecosystems. Built on his

background in science and research as well

as his passion for creativity, Tao strives to

create aesthetically pleasing designs rooted

in a deep understanding of ecosystems and

their cultural contexts. The complexity of

the contemporary urban landscape requires

thoughtful consideration of not only human

experiences but also the dynamics and

processes of the physico-chemical systems

and habitats for other species. His work

ranges from large-scale conceptual plans to

site landscape designs. Bridging between

urban design, landscape architecture and

ecology, Tao has contributed to creating

a number of vibrant new urban districts

and public parks. Tao is also engaged in

academic activities by publishing at peer

reviewed journals and speaking frequently

at conferences.

Tao ZHANG citizen. I think it is everyone’s responsibility to care about our water, not only for ourselves, but also for the generations to come. As a landscape architect, I always treat water as one of the most important resources and often the inspiration of my design. I think we can try to bring public awareness to the water issues through our design. For example, we can daylight buried rivers to be part of the desirable water features in our cities. We can also design bioswales to collect stormwater instead of relying on the engineered underground pipes. We should try to preserve and protect the existing natural water bodies when we do large-scale landscape planning. They should not just be treated as commodities for development opportunities.

LR: Why is rainwater management so important? What are the benefits of sustainable water management design?

Tao: Rainwater is a critical step in the water

- An interview with Tao Zhang, Sasaki

Landscape Architect, Ecologist, Associate of Sasaki

Jiading Central Park

Landscape Record Vol. 1/2015.02 121

STORMWATER MANAGEMENT STRATEGIES

cycling in nature. Without healthy water cycling, we would face many challenges and even disasters. If rainwater is not drained properly, our cities are inundated or flooded. Ground water depletes without a sustainable recharge from rainwater through the soil. The benefits of sustainable water management design can help alleviate the urban pressure on the natural water cycling through the ecosystems. By collecting rainwater through bioswales, rain gardens, and detention ponds, we can treat stormwater on site by increasing infiltration, bioremediating urban pollutants, and reducing runoff that may cause flooding.

LR: Clients, especially private owners, might be concerned that rainwater management will cost a lot. How do you convince your clients to invest in rainwater management?

Tao: I think it is a common myth that rainwater management will always cost more. We have to look at the question case by case. Sometimes it is true that it will involve more upfront investment, but often it is the opposite, especially in the long term. We understand that the client may be concerned about the cost and we do not judge them for that. We always try to investigate the local climate first for the optimum solution. A sustainable solution for one site might not be so at all for another site. For example, the approach to deal with stormwater in a tropical city with ample precipitation is totally different from that for an arid area. To have a fair and candid conversation with the client, we would quantify

the amount of stormwater and any economic and social impacts of the different design solutions. Then we would let facts speak for themselves. The best solutions would be the win-win situations when the client could save money and the environment will be improved too.

LR: If you were commissioned with a project with a very limited budget, where will you put your money in

terms of rainwater management? Are there any most cost-effective ways?

Tao: This will have to be case specific. I find it counterproductive to generalize in design. Nature is so dynamic and diverse. There will never be a one-for-all solution. For one project, native planting might be the priority. Yet for another site, it could be a forebay to settle the sediments first. So it really varies.

LR: Could you please describe a certain project (or a few) that you worked on with excellent rainwater management design? What special techniques have been applied? Any challenges?

Tao: Jiading Central Park is one of the projects where I participated in a series of ecological and sustainable designs. The techniques applied included installing bioswales, restoring river riparian zones and wetlands, and installing cisterns for rainwater storage. One of the challenges was that we had to convince the client and the contractors that what we proposed was doable. because of a lack of successful precedents, people were skeptical whether our design solutions were just theoretical and too idealistic, but all of our design decisions were based on thorough studies and our rich experience with challenging projects around the world. The final result was a success that reassured everyone of a right approach.

Jiading Central Park

Jiading Central Park

INTERVIEW

Landscape Record Vol. 1/2015.02122

a landscape architect and ecologist.

LR: What do you enjoy most in your career as a landscape architect? Are there any special stories you would like to share?

Tao: Landscape architecture is a unique

LR: An increasing amount of rain gardens have been installed worldwide. What, in your opinion, are the important items to consider when planning a rain garden?

Tao: I think there isn’t a universal most important item for all. The most important thing to consider is that the rain gardens are climate and site specific. Precipitation patterns, soil types, and slope conditions all have significant impacts on rain garden design.

LR: What types of plants will you suggest for planting in rain gardens?

Tao: I recommend native plants that thrive in a floodplain, because they are best suited to the local climate and rain pattern, and they can tolerate both inundation and drought. Again, they are region and site specific.

LR: How about the pavement? Or other elements like soil?

Tao: Permeable pavement is always highly recommended. More importantly, all the sub layers and underlayment have to be permeable as well. I have seen permeable pavers incorrectly installed on top of solid sub layers which prevent infiltration and create sub layer sheet flow.

LR: How do you make a rain garden low-maintenance?

Tao: I am referring back to my answer to the question about planting. Native plants that thrive in a floodplain are recommended. If you are choosing the specimens that fit the local soils and climate the best, nature will do the most of maintenance for you.

LR: How does the local climate affect your design?

Tao: It’s part of the fundamental understanding of a project in our practice. Along with other environmental parameters, it dictates our design thinking from the very beginning.

LR: Is there anyone (or anything) who inspires you most as a landscape architect?

Tao: Yes, but there isn’t any particular single person who is my source of inspiration. I draw most of my daily inspiration from my colleagues, from entry level to the most senior designers. I find it inspiring to learn something different and new every each day by working with them. I think that’s a big source of motivation for me as

integration of science and art. The creative pursuits and seeing my ideas make positive changes to the environment are quite rewarding. I can be idealistic sometimes and pragmatic at other times depending on the scope and type of the projects.

Jiading Central Park

All images and drawings provided by Sasaki