MANAGING WATER RESOURCES
The key factor that facilitated the development of these societies was the prevalence of water. Ample rainfall and an abundance of surface water sources—streams, rivers, springs, and waterfalls—shaped the landscape and gave the agroforest belt its vitality. These were essential to the intensive agriculture of the vihamba and the high-density settlements that formed on the mountain’s ridges. Over centuries, people developed intricate ways of managing their resources. They also came to understand the natural patterns of rainfall and stream flow, as well as the challenges of periodic drought. People did not utilize water passively; they actively managed it.
The mountain offered many natural sources of water, including rainfall (see table 1.1), springs, streams, rivers, and waterfalls, as well as man-made irrigation works. These sources each had different characteristics that mattered to users: proximity to the homestead, ease of access, seasonal availability, turbidity, taste, spiritual significance, and claims of ownership. Therefore, most people practiced a multiple-source water economy, in which they procured water from different sources, at different times of year, and for different tasks. Rain was the one source of water utilized by all, as it nourished the crops of the vihamba. Surface water sources could supplement rainfall during the dry months or prolonged periods of drought, but more often they were used for domestic purposes such as cooking, brewing, watering livestock, cleaning, and manufacturing mud blocks used for construction. Decisions about where to collect water were highly localized and dynamic. Patterns of water usage were as unique as the people themselves, varying from homestead to homestead and over time. Though individuals could make claims on naturally occurring water sources, this did not imply ownership, as it was forbidden to charge people or accept payment for water from these sources.38
Perhaps the most notable surface water feature was the extensive system of man-made irrigation canals known as mifongo (sing. mfongo).39 These were excavated ditches designed to divert water from rivers and channel it, using the power of gravity, directly into areas of settlement, where it could then be used for irrigating vihamba and shamba as well as for domestic uses. Mifongo came into use between two hundred and four hundred years ago. The technology was likely imported from neighboring areas with histories of irrigation development,40 and it developed into the most extensive system of mountainside irrigation in Africa. It is difficult to know the number of canals that existed in 1850, considering the lack of data and the challenge of counting a system that was by its nature dynamic; canals were built, abandoned, and resurrected in response to need. In the 1920s, Gutmann estimated that as many as one thousand canals lined the slopes of the mountain.41
Mifongo across Kilimanjaro (fig. 1.2) shared common design characteristics. Each began with a dump (nduwa), a swell within a river that would provide a consistent supply of water. From here, an intake (kiwamaenyi) constructed from banana trunk diverted the water into a main canal, which turned away from the river and toward its destination. From this point, the waters flowed downhill at a gradual slope. Once they reached their destination, they were again diverted, this time into secondary canals leading directly into the vihamba. Floodgates made of banana trunks and leaves prevented water from flowing into the secondary canals until the appropriate time. Water from canals could be gathered into a wooden container, gourd, or clay pot for domestic purposes, but most often it was used for flood irrigation of crops. Beyond these general design characteristics, canals had a number of variations. Some canals that drew from small rivers featured multiple intakes to maximize the water supply. Many had culverts or aqueducts to lead water over other streams or under heavily traveled paths. Some had reservoirs that stored the overnight flow and increased the amount of water available during daylight hours. The biggest variables were length and number of branch canals. Mifongo could be as short as a quarter of a kilometer or as long as several kilometers, with only a handful of branch canals or dozens.
TABLE 1.1. Mean monthly rainfall in millimeters for selected locations (minimum 10 years of recorded data)
Data from Paul Maro, Population Growth and Agricultural Change in Kilimanjaro, 1920-1970, research paper no. 40 (Dar es Salaam: University of Dar es Salaam Bureau of Resource Assessment and Land Use Planning, December 1975).
FIGURE 1.2. An mfongo (Matthew V. Bender)
The development of new mifongo was a highly ritualized process limited to men in the community. Custom expressly prohibited women and children from tasks related to constructing or maintaining them.42 The process of creating a new canal began with a group of men’s determination that a new one was needed. They designated a leader, or founder, who took the lead in organizing labor and designing a plan for the canal. All men who planned to use the water aided in its construction and ongoing maintenance. Once the labor had been assembled, the founder began the process of surveying of the route.43 For areas with clearly defined slopes, he determined the path by eyesight alone. Where the slope was less clear, he could survey the land by placing a banana leaf on the ground, pouring water from a calabash, and seeing what way that water flowed. Alternately, he could study the walking paths of fire ants to determine the slope.44 After determining the path and slope, the founder commanded the men to excavate the primary canal to the desired depth and width. Once they completed that, they constructed the canal intake by excavating an appropriately sized opening from the source river and building the weir using banana trunks. Lastly, each man excavated his own branch canal from the main one. Once the project was complete, the founder became the first meni mfongo (canal headman), who held responsibility for its continuing management. Although most mifongo were designed by one of the users, some were constructed on others’ behalf by professionals who served as experts in irrigation management. Those who designed successful mifongo gained a reputation, and this translated into a powerful social status. In Kilema, the names of the most esteemed canal founders in history—Anjelini, Maleto, Matanda, Mchau, Mtenga, Mlikamburu, Reu—are remembered to the present day.45
Considering the richness of the landscape and the relative abundance of water, one may ask why people went to the trouble of constructing such an immense network of canals. One reason is that mifongo allowed for more flexibility in cultivation. Relying on rainfall alone, farmers were limited to two growing seasons—during and following the kisiye and fuli—in all areas of the agroforest belt except those of highest altitudes. With irrigation, they created a year-round agricultural calendar and maximized their land and labor resources; eleusine cultivation is a great example of this flexibility. A second factor was the challenging placement of natural watercourses relative to areas of settlement. Many of the principal rivers lay in deep ravines as they passed by the vihamba. Women and children, responsible for procuring domestic water, had to descend a steep slope, fill a clay pot with water, and then ascend with the pot atop their head. These inclines were difficult to climb and were often on borderlands. Harry Johnston recalled hearing stories about women who were kidnapped while gathering water from rivers and then forced to become junior wives of their captors.46 Animals such as leopards and lions also frequented these areas. By providing a reliable supply of water directly into areas of settlement, the mifongo not only reduced the risks associated with procuring water but also eased the labor burden. Lastly, mifongo provided a safeguard against drought. Though men irrigated vihamba regularly, they did so with increasing frequency in times of drought to compensate for insufficient