Floating Ponds: A Vertical Aquaculture Farming Typology
Space Based Vertical Fish Farm as a Self-Sustained Urban Typology
The productive and operational viability of vertical farming has thus far been largely restricted to the farming of green leafy vegetables. This Vertical Aquaculture Farming project is one of the pioneering attempts at taking land-based fish farming vertical. This is significant as the main nutrient yield here is protein, which also has a higher value economically in comparison to green leafy vegetables. The success of this typology can considerably boost the possibility of future urban food resilience both in-terms of productivity per unit land area (critical to dense urban developments) and nutritional value.
The design for this farm is anchored to two fundamental strategies:
The purpose-engineered closed-system water reticulation system developed by the owner (Apollo Aquaculture Group) – which makes vertical stacking of the fish raceways functionally possible and;
The systems approach to the planning of the farm which helps to create a self-sustaining typology.
Adopting a Systems Approach:
Figure 1: Systems Map
The planning is founded on a comprehensive integration amongst the three main systems that are engaged by the farm –
Water
Nutrients
Energy
A systemic integration of the above systems, leads to a scheme which creates a closed-loop farming eco-system. The systems map (Figure 1) shows the embeddedness of these systems in this design scheme and is predicated on flows and exchanges amongst these three systems. The spatial design and architecture of the farm thereafter works towards enabling these exchanges. The architecture is thus a facilitator of the system flows and exchanges and coordinates their integration.
Modular and Scalable:
The closed-system water reticulation system (Figure 2) allows for two significant enhancements - first it makes each fish raceway an independent closed-system unit thus lending it modularity; and second, together with the light-weight design of the raceway, it enables their vertical stacking. These are significant innovations which make the farming system scalable - along the horizontal and the vertical. Such modularity and scalability makes it a perfect fit for dense urban environments where the typology could be customized to fit any available space (and not necessarily land); and by stacking up the fish raceways, it shall enhance the productive intensity of the available space.
Figure 2: Schematic diagrams of the fish raceways together with the water filtration system.
Design Scheme:
The physical planning of the farm translates the systems flow-chart to a spatial arrangement of the various entities on the site (Figure 3).
The farm comprises of two main types of built volumes:
Fish Tanks are the production areas – they house the modular raceways for breeding the food-fish species.
Support Spaces - which include offices, a visitor centre, cafeterias, control and command centre, a processing and packing area, workshops and other support facilities.
At the heart of the site layout, lies a series of constructed wetlands to which are connected a network of bio-swales streaming through the various built forms on the site. The wetlands split the fish tank into two separate blocks. This juxtapositioning of the blue-green network with the farming blocks is essential towards facilitating the planned systems exchanges.
Figure 3: Site Plan
Figure 4: Site Section
Figure 5: System Diagrams
Water:
The role of water is paramount to this project. While the handling of water within the fish raceways itself is controlled by the engineered reticulation system (its operation being critical to the health and cultivation of fishes); it is the designed flow of water outside the fish tanks (within the remainder of the site) which creates the medium for the systemic exchanges to take place. These are illustrated in both figures 4 and 5.
Expunged waste water from the fish tanks is channeled to the constructed wetlands. Bacteria and aquatic plants in these wetlands cleanse the water by feeding on the waste it contains which is organic fish wastes laden with rich nutrients. The ‘cleansed’ water can then be used for several non-potable uses including being re-circulated back into the fish tanks after additional mechanical treatment. The water re-entering the fish raceways need to be further treated including injecting it with specific bacteria which are essential for the breeding of the fish species. Another viable and simple use of the expunged water is hydroponics which would enable the production of green leafy vegetables by using this nutrient rich water.
Bio-swales augment the system further by capturing and conveying surface run-off to the central wetland system. This overall water system helps to reduce the demand for clean potable water in the fish tanks and to reduce the volume of water being finally discharged out from the site into the sewer system.
Nutrients:
Besides the primary source of nutrients being created by the production of the food fish species, there is viable potential to create several additional sources of other nutrients. The aquatic plants in the wetlands become one such essential nutrient source. They help to close the nutrient loop as a certain quantum of them is processed back to become feed for the fish. In addition to aquatic plants, micro-algae are also cultivated using the nutrient laden waste water as feed for the fish. Algae are also used to condition the sea-water which is also used as a source of topping up.
Hydroponics further adds to the production capacity of green leafy vegetables by directly using the nutrient rich waste water from the fish raceways.
Energy:
Active energy production: The fish tanks require a large covered-space to keep off excessive solar heat and sun-light. This expansive roof provides a platform for the installation of sizeable arrays of solar-photovoltaic panels on the available roof space which can generate substantial energy to offset consumption demands.
(A rough estimate of the productive capacity of the PV system is shown in figure 7)
The other potential source of energy would be to use algae. Algae grown in transparent tubes and pumped with waste water and a lot of CO2 can produce bio-fuel in the presence of sunlight. This is a potential technology which has had variable degrees of proven success in certain projects across the world. For this project, this is identified as a technology which holds future potential.
Passive measures: Besides producing energy, the premise (especially the fish tanks) is designed to maximize thermal comfort and mitigate energy consumption. The primary focus is to reduce the need to mechanically ventilate the large fish farming blocks.
This is facilitated by first orienting the blocks to benefit from the prevailing winds; and second - the design of the porous envelope which allows the prevailing breeze to permeate through to these large spaces. The two-layered envelope around the fish raceways helps to keep the ambient light levels low and the space naturally ventilated – both of which are ideal conditions for fish breeding whilst ensuring a bio-secured environment for their breeding. (refer figure 6).
Figure 6: Schematic Section through the fish-farming block
Making Farming Visible and Creating 'Interest'
Urban farming is gradually making in-roads into many intensely urban spaces like those in Japan, Korea, Indonesia and parts of China.
But urban food resilience should not only be about planning for highly productive and self-sustaining ecosystems, but also about making farming visible to the community; thereby encouraging their active participation.
Visibility of such innovative land- based vertical fish farming can contribute to creating an interest amongst the society in a ‘modern’ concept of farming. The design of this vertical fish farm enables, visitors to walk in and around the farming blocks (whilst still segregated from the bio-secure environment of the fish raceways) and experience the ambient space and the cultivation of ‘food’ therein. Several researches are showing that such access to urban farming not only promotes community participation but more significantly lends a therapeutic relief from the constant myriad stresses of the urban pressure chamber.
Knowing our food source, seeing it nurture and participating in its cultivation may soon become an essential part of urban living.
The unique water-handling system of the farm together with the closed-loop framework offers a 'clean' fish farm which can take high-value (nutrient and cost) food production out of conventionally isolated and secluded land-based farms and place them into the heart of high-density urban cores, as inclusive elements of the social sphere. Together with already prevalent green vertical farms, floating ponds can become part of future urban spaces to support their food resilience.
Figure 7: Planning for a closed-loop vertical fish farm which allows for systemic flows and exchanges.
Figure 8: Image of the functioning prototype built to test the vertical stacking and the water reticulation system.
Figure 9: Blue-Green infrastructure becomes an integral part of the farming ecosystem.
Project Data:
Project Location: Singapore
Status: Design Stage
Site Area: approx 3.5 HA
Floor Area: approx 41,000 sqm
Clients/Owners: Apollo Aquaculture Group
Consultants: Surbana Jurong Consultants Pte. Ltd.
Images: Surbana Jurong Consultants Pte. Ltd.
