SITE
Megadam GIBE III Megadam
Food Security
Affected Area Minimal Stressed Crisis Emergency
THE PROBLEM Home to the 3rd lowest access to potable water per capita (18%) yet the greatest water reserves in Africa and source of 85% of the Nile River, Ethiopia is ironically referred to as the “Water Tower of Africa.” This problem grows exponentially as the world’s largest landlocked country, home to the world’s 9th largest population of over 228 million by 2050, and the 7th worst standard of living according to the United Nations Human Development Index. While Ethiopia has turned its focus to its “white oil”—water—it is purely for energy reasons with 14 new megadams to be constructed by 2015 that have severe environmental and social implications yet to be studied; the Gibe III Dam—currently under construction with 2 more dams scheduled downstream—will negatively affect 500,000 people downstream. Unconsulted—in breach of Ethiopian law—the indigenous tribes will be forced to move from their regular water source; this lobotomy uproots cultures, traditions, livestock, trade, lifelines to southern national parks, and flood-recession agriculture. Gathering water has become a ritual, refined over generations and highly dependent on flood cycles of rivers in the region for the sediment they leave behind. These migrant peoples are directed to convert to sedentary agriculture on the newly sediment-deprived land, making their knowledge gained over millennia obsolete within months. As 41% of Ethiopia's GDP and 80% of Ethiopia’s labor rely on agriculture, the country is # unavoidably dependent upon the extraction and distribution of potable water. Yet millions require food assistance annually. Even more dependent upon water are the migrant tribes, constantly searching for potable water, grazing land for their cattle, and access to migratory fish. Water scarcity has already created dangerous inter-ethnic conflicts; this will be exacerbated by Ethiopia’s extreme poverty, future droughts, and the megadams’ irreversibly altered seasonal flooding and reduced volume.
WATER TO POPULATION DENSITY 2
Population (in millions) 228
16 187 MILLION PEOPLE WITHOUT REGULAR ACCESS TO CLEAN WATER
114
Year
0 1950
2000
54
8 4
39
8
19 31 27
8
4
Population Population WITH regular access to clean water Gibe III Affected Area (58 million) Low Density per # Water Basin # 2050 Estimated Population # (in millions) High Density per # Water Basin
2050
THE SOLUTION This proposal for a series of water purification centers and resettlement housing accepts the inevitability of these dams—due to the unquestionable power of the Ethiopian government—and attempts to help those affected by this travesty. Through a collection, filtration, and distribution system, the Water Stelae connect people with a continuous source of clean water, their crops, and other tribes, bridging the vast height from plateau to river. As historical stelae mark the location of a sacred space below, the fabric-canopied Water Stelae mark the entrance to a space of secure water and life. Native fabric collects condensation and shades the sun and dust; the earth excavated filters the collected water along its journey; a composting terra preta system fertilizes the soil, and a locally governed acequia system distributes the clean water to the surrounding area in these new migrant community centers. As the southern Nyangatom tribe and northern rock-hewn churches of Lalibela, the Water Stelae dig deep into the earth to extract water. The Water Stelae continue the indigenous peoples’ ways of life and ensure ever-lasting access to clean water.
Rehydrating the Omo River Valley
WATER STELAE PERMACULTURE
CULTURAL INFLUENCES
Ethiopian agriculture consists of a mix of pastoralist and sedentary farmers. Due to the harsh terrain of steep plateaus and deep lowland rivers, Ethiopian farmers utilize terraced farming. The terraces are designed to retain the ideal amount of water while exerting the remaining water to the terrace below. This type of farming creates an ideal situation to utilize the placement of the tower within the topography. Excess water from the encompassing ring of the tower is drained into the terraced farming below, creating a continuous and dependable water supply that is resistant to seasonal droughts.
+ + = − Obelisk of Axom, Ethiopia
Human Water Chains
The Church St. George, Lalibela, Ethiopia
Omo River Valley during flood season
Omo River Valley with essential sediment
retention from floodwater for farming
Gibe III Megadam terminating flood season, restricting flow and essential sediment
Water Stelae revitalizing Omo River Valley through irrigation and fertilization
Typical skyscraper
The agriculture is further supplemented by the Water Stelae with nutrients from its occupants’ waste. The solid waste is combined with the soil to create a nutrient rich terra preta soil. The liquid waste is used to fertilize the crops. These supplemental nutrients nullify the effects of the reduction of essential nutrients retained by the dam and lack of seasonal flooding. Through the design of the tower and surrounding site, an ecological balance is restored that is vital to life in the Omo River Valley. Water Stelae
AVERAGE AIR TEMP 80º F
DIRECT RAINWATER COLLECTION PASSIVE WATER CONDENSATION COLLECTION 1
WATER COLLECTING SURFACE
3
4
Perspective looking down beyond fabric condensation collector toward water celebration spaces
Market
2
Well (Ground Water)
SURFACE TEMP 72º F
COLLECTED WATER FILTERING
Water stelae mitigates temperature spikes through evaporative cooling, providing more condusive living conditions.
Water is separated into compartment “leafs” as it moves vertically. the stone “stelae” contributes to the filtering process of moving water .
1. WATER STELAE The water stelae serve the dual function of both a condensation collector and as a symbol of civic pride. The Stelae, in the historical sense, are highly articulated stone structures that mark the location of underground structures and the pride of the region. The Water Stelae still serve these functions, but in a unique manner: instead of an articulation in stone it is an articulation of form. The
light and airy wrap is a physical representation of condensation collection, representing hope of a sustainable future. The form of the Water Stelae is generated from the water collection methods of the ice plant and hydrologic cycle. The ice plant collects surface water through epidermal bladder cells; this collection and storage method allows the plant to retain water even in water-stressed areas. Utilizing this technology, a pocketed fabric is created that can collect and retain water even under drought conditions.
The vertical flow is modeled after vortical fluid dynamics, creating the spiraling structure. The spiraling flow of the water is the most efficient and safe way for a fluid to travel vertically minimizing water exposure to atmospheric conditions. The water is delivered to a central core that is equipped with micro-turbines that capitalize on the water’s energy. A highly efficient form that is also a symbol of civic pride is created.
Perspective in central market toward celebrated filtered water
GREY WATER FILTERED THROUGH SLOW SAND FILTER
DEW POINT 58º F The evaporated water vapor collected from the well transforms back to its liquid state and is collected by the stelae.
HO ²
Water generated by the water steelae matriculates at a single source providing regular access to cllean drinkking water. Political hostility between communities is lessened with more regulated accesss duee to the collection and storage capabilites of the water stelae in such ann arid and volatile climate.
2. CAPILLARY + TRANSPIRATION TUBES Acting similar to the xylem of a tree, thin tubes surrounding the ground opening draw groundwater vertically from the earth and well below. As the water moves vertically, hydrostatic pressure increases, creating a passive pump action. The tubes have thin pores, similar to stomata on leaves, giving it evaporative qualities; with the combination of capillary action and transpiration, the water will reach heights similar to that of a redwood tree. Gravity is overcome by the decrease in hydrostatic pressure due to the diffusion of water from the stomata. The resultant is a passive system to lift a constant, regulated amount of ground water to the surface.
3. SLOW SAND WATER FILTRATION
SPACES FOR SPIRITUAL REPOSE AGRICULTURE Crops cultivated from terraced farmland help to sustain indigenous people and provide a means of commerce.
Slow sand water filtration is a passive, chemical free, three-part water filtration system. The top, schmutzdecke layer—the most effective in catching microorganisms—consist of bacteria, algae, and other micromatter. The schmutzdecke layer is developed by residue collected on the sand base below; it matures as organisms begin to adhere to each other and the layer thickens, creating a more efficient filter. Filtration without the schmutzdecke is only about 60% adequate. The water is mechanically filtered in the remaining layers are sand and gravel. As the size of the sand granules decrease, remaining particles with the ability to escape the schutzdecke layer are caught in the finer granules. Through this passive process, clean water is accessible in remote regions.
WELL WATER 50º F The cool well water is lifted to the surface through evaporation. the warm surface air creates a vacuum pulling the water up.
4. “A PLACE OF SPIRITUAL REPOSE”
BLACK WATER ⁄ SOLID WASTE Solid waste collected at the base of the stelae is delivered to the agricultural land and combined with the soil to create terra preta soil.
Perspective looking up beyond capillary tubes toward water celebration spaces
Historically speaking, Ethiopian culture created sublime spaces within the earth, such as the ancient rock-hewn churches of Lalibela. These spiritual spaces emphasize the qualities of the subtractive and the mystery of shadows. The deep and subtle space is a refuge from the chaos of the external and fosters a connection with the spiritual, a connection with nature and the earth itself. One experiences a space with small sensations of light trickling down stone walls revealing their weathered veins and hints of moss, exposing only a faint feel for a space hidden in the ambiguity of the shadows. The atmosphere of the tower is further enhanced by the hint of cascading water echoing through the reveals, a sensation that is not only heard, but felt through the humidity. The result is a spiritual skyscraper of shadows intertwined with the earth, a place of repose.