The Secret to Winning at Neighboursheds

A watershed is conventionally known as an area of land that captures and drains water to a common point of discharge. It is a system where topography governs the flow of water through the landscape. Against an increasingly urbanized world, however, it is evident that this traditional notion of the watershed has not been displaced fast enough or far enough to accommodate human activity. In many cities today, the urban environment and watershed are two distinct territories, linked together by a series of pipe networks. The urban grid and site design bears no semblance to the actual natural watershed.

In Batam, the pristine watershed has been contaminated by rapid urbanism. Protected areas within immediate proximity to Batam’s drinking reservoirs have been encroached upon by housing and industry, clearing large tracts of forested land that had served as water catchment area, while discharging enormous quantities of untreated wastewater into the environment. The watershed’s capacity to retain stormwater is reduced and its ability to cleanse itself naturally weakened. Consequently, the city is plagued with severe rainfall-induced flooding and rising water scarcity due to poor raw water quality. At the same time, its urban water infrastructure is succumbing to the pressures of increasing water demands, with sectors of the population experiencing water supply disruptions daily.

My thesis seeks to define a new form of watershed, using the concept of “neighboursheds” – a term I use to describe a neighbourhood-based watershed. Each neighbourshed is defined by the perimeters of a neighbourhood community and has its own grammar of collecting and managing water. Strategies employed are site-specific calibrations to the different financial, topographical and pollution realities in each neighbourshed. The “neighboursheds” scheme is a system of distributed water infrastructure located at the community level. It intermediates between two extreme scales in Batam’s urban water system – the large, highly-centralized city reservoirs and the small, household level of domestic wells.

The chosen site for the project is the region of Sei Panas, nestled in the middle of Batam’s three most highly populated districts and home to the smallest but most highly-polluted reservoir, Sei Baloi. In 2012, Sei Baloi was shut down after authorities deemed it to be beyond remedy. Since then, Sei Panas has been experiencing one of the highest rates of flash floods and water supply disruptions.

The site is divided by land use into four neighboursheds, each at a different standing in the socioeconomic strata.

The blue lines represent the project’s intervention, or ‘acupuncture’ points in the neighbourshed. The higher the socioeconomic standing of the neighbourshed the fewer acupuncture points per area is required.

Neighbourshed 1

At the lowest rung of the ladder is the informal housing settlement, which is further broken up into subneighboursheds each comprising 15-30 households along pre-established pathways.

A repetitive deployable system with minimal aesthetics is implemented here. Rainwater collected from the rooftops of homes is channelled outwards by gutters into a network of water channels which then feeds into a rainwater tank planted in the heart of every cluster. A perimeter of empty space surrounds the water body to objectify it and avail it as a community gathering space. It takes the recognizable form of a circle to serve as an orienting device. The entrance into each cluster is also marked by a grove of banana trees where greywater collected from households is discharged. This supports the growth of the banana trees, which thrive on nutrients from decaying organic matter.

Neighbourshed 2

On the next rung of the ladder is a resettlement site where previous squatters have been newly relocated to.

Neighboursheds of 30-40 households develop in a linear fashion along a drainage channel that runs down the hillside and terminates in a bio-sand water filtration tank - a water kiosk where clean water can be drawn from. An enclosure marks the location of the kiosk and residents descend to the foot of the water tank through a spiral ramp.

Rainwater is directed by gutters into culverts that extend into the drainage channel as baffles to retard the flow of water down the steep gradient. The gutter downspout is displaced from the centre of the roofline as a counterpoint to the symmetry of the building’s elevation.

By rendering visible the flow of water from point of collection to point of discharge, the position of water in people’s consciousness is elevated and a stronger connection with water is drawn.

Neighbourshed 3

The third neighbourshed comprising formal housing sits on one of the higher rungs in the socio-economic stratum. It has the highest degree of formality and level of order amongst the residential neighboursheds, thus requiring fewer acupuncture points per area.

Here, each sub-neighbourshed consists as many as 80-120 households. The flat roof is profiled to lead water into gutters that wedge in between alleys, draining into a community cistern located at the end of every block. The overflow of water from these cisterns is then channelled via overhead gutters to irrigate and support reforestation at vacant sites across the neighbourshed.

At each reforested site, rainwater is discharged into a circular receptacle before it flows into a linear trough that directs one along a path towards an irrigation tank. The path cuts into the circular pool and a concrete stairway allows one to descend to the level of the water surface.

Neighbourshed 4

Finally, sitting on the upper end of the strata is the industrial neighbourshed which consists of factories and warehouses owned by MNCs. Strategies proposed for this neighboursheds requires the greatest capital deployment.

Highway setbacks are converted into a series of reed beds to store and treat rainwater collected from the roofs of warehouses, thereby forming an interconnected sequence of gardens, framed by stormwater aqueducts along the highway. As the water travels from both ends of the highway down to the midpoint, it undergoes a natural process of filtration and is at its purest at the lowest point of the topography. Here, a water treatment plant purifies and treats water that can then be distributed and sold to the residential neighboursheds through an aqueduct bridge spanning across the highway. Water collected in residential neighbourhsheds is non-potable; it is only here in the industrial neighbourshed where water can be made potable through purification.

Ancillary structures that are added to the roofs increase rainfall catchment area and gives rhythm to the roof profiles.

Ladders diagram - water network flow logic

Sub-neighbourshed divisions

Conclusion

It takes a village to protect a watershed. Neighboursheds are an alternative to the state’s singular system of water provision where people have been absolved from the responsibilities over the well-being of their watershed.

By incorporating water infrastructure as an essential visual component in the urban environment, the “neighboursheds” framework sets up a new contractual relationship between people and their watershed, thus enabling the safeguarding of water sources through community-level action.