Water Wheel is Local Indigenous
Knowledge on Irrigation Scheme
HouaPhanh Province is located in the north of Lao PDR, where the geography is mainly high and sloping mountains and valleys and thus the livelihood of ethnicity villagers faced to many difficulties, especially to cultivate wet-rice in paddy fields where much of the cultivation land is higher level than the water level of the rivers or streams, and where this paddy land requires supplementary irrigation to produce good yields. In many cases it is not possible to construct an irrigation weirs in the upstream areas of the wet-rice lands. Therefore, villagers have devised a method - many years ago - to take water from the river to provide supplementary irrigation to their cultivation paddy land by the use of a 100% locally made - bamboo and wood - water wheel that local people call “Lok” or “Kong Phat Nam”. As study was recently undertaken of the many water wheels that are successfully built and managed by villagers along both sides of the Nam Xam River, to supply water to paddy rice field of villagers living in villages in Goomban Him and Goomban Meuang Vene, of XamNeua District of Houaphanh Province.
At the present time, there are 18 water wheels in Him Village, 10 units in Piane village, 4 units in Natang village and 9 units in Khong Village. The total numbers of villagers who use these water wheels is 99 households, and the area irrigated is 68 hectares. The water lifting and irrigation capacity of one medium size water wheel is 188 liters per minute.
The preparation and construction of these water wheel must be started in the dry season, March, when the villagers preparing all the necessary materials, equipment and tools such as the wood, bamboo, natural roping, knives, hammers etc. They then start to carefully construct each part of the water wheel, following an ancient ‘tried and try’ method, section by section. The wheel is finished and in place, on the side of the river, at the start of June, which is the beginning of the wet season, and also the time to start preparing the land for cultivation every year.
A crucial part of the waterwheel system is the temporary dam/weir built across the river every year. This dam is constructed from wooden 3-legged stays, and palm leaves, to check the water and cause the water to be directed towards the water wheel, on the side of the river. This causes a higher velocity - and kinetic energy - of the water directly under the water wheel, which is enough to turn the wheel and is many bamboo containers full of water.
This low-level, wood and palm leaf weir across the river reduces the water flow and increase water level a little, and it actually promotes or improves the habitat of the aquatic animals, and is a good fishing spot for villagers.
The water supplied by the water wheel is usefull not only for supplementary irrigation of the paddy rice fields, and for vegetable production, but it also supplies water for raising aquatic animals such the fish, frog, crab etc… for both household consumption and for selling to earning incomes. In addition, the number and variety of aquatic animals in the wet rice fields is increased, as baby aquatic animals are often scooped-up by the water-wheels’ bamboo containers, from the river, and transported to the paddy fields.
But this indigenous water wheel does have some limitations, in that (a) it can be easily damaged by high water flow from heavy rain, and (b) it cannot function during the dry season if water level in river is too low.
The study, measuring and documentation of the indigenous water wheels in Him Village of Vene village cluster in XamNeua District of Houaphanh Province was supported by The Agro-Biodiversity Initiative (TABI), which provided financial and technical support. The objective of TABI support is not only to record, for posterity, the local and ABD-based irrigation system, but also to start to explore with villagers how to use their skill and indigenous knowledge to enhance the sustainability of use local natural resources for improving their household livelihood and labor saving.
Photo: Christopher Flint and Vanxay Bounthavongkham
News: Vilaylack Khounvisith