From Open ABM website html 
An interesting example of emergence and complex adaptive systems in social systems is irrigation in Bali, Indonesia. Farmers who irrigate their fields in Bali have to solve a complex coordination problem that emerges at the intersection of two separate issues: pest outbreaks and water shortage. On one hand, control of pests is most effective when all rice fields in a watershed have the same schedule of planting rice. The reason is that rice is harvested at the same time and no food for the pests exists in a larger area to survive. If harvest of rice was in small fields only, pest can survive after a harvest by moving to a neighboring field where rice is still on the field. On the other hand, the terraces are hydrologically interdependent, with long and fragile systems of tunnels, canals, and aqueducts. Therefore, to avoid water shortage, the irrigators should not plant rice all at the same time. To balance the need for coordinated fallow periods and use of water, a complex ritual system has been developed that details what rituals and actions should be done on each specific date in each organized group of farmers—called a subak (link is external). These actions are related to offerings at temples, ranging from the little temples at the rice terrace level to the temples at the regional level and all the way up to the temple of the high priest Jero Gde, the human representative of the Goddess of the Temple of the Crater Lake. Crater Lake feeds the groundwater system, which is the main source of water for irrigating in the entire watershed. These offerings were collected as a counter gift for the use of water that belonged to the gods. There is no person who has control over the whole irrigation system. At the temple level, subak leaders come together regularly to exchange information on their irrigation experiences in their subaks. When a particular subak makes a decision that has unfavorable effects on neighboring subaks, leaders of the local temple community come together to discuss these matters. This may lead to various actions, including the threat of cutting-off the water supply to the disrupting subak. When seasonal rainfall is different than expected, subaks leaders may come together to discuss alternative cropping pattern to avoid unfavorable circumstances.
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