Balinese rice cultivation is famous all over the world for its efficient use of irrigation water. At the heart of irrigation management are the water user associations called subak. They are the backbone of Balinese rice cultivation.

Subak has been described by several authors. It is commonly recognized as an autonomous socio-religious association which deals with matters related to the cultivation and irrigation of rice. They have evolved over centuries, organized by the farmers themselves without (or little) guidance from central authorities. The subak are considered to be one of the most effective irrigator organizations in the world.

The general Balinese philosophy guiding the subak system adheres to the principle of Tri Hita Karana which emphasises that happiness can only be reached if the Creator (God), the people (the farmers) and nature (the rice fields) live in harmony with each other. Based on this philosophy are the ceremonies which are a substantial part of the rice cultivation cycle. The ceremonies are carried out at the various temples which are associated with the subak.

The Tri Hita Karana philosophy is also the basis for the clearly defined rules of a subak, called awig-awig. This set of laws regulates rights and duties among the members. It includes public obligations, regulations concerning land and water use, legal transactions of land transfers, and collective religious ceremonies. For instance, all members have the right to the same share of water at all times. This principle of equitable water sharing is put into action by fixed proportional flow division structures.

Subak internal matters are handled by the pekaseh, the subak head who is democratically elected by all members of the subak. He is responsible to overlook the irrigation management within the subak area, to schedule cultivation cycles and to organise subak ceremonies. He is supported by several assistants, such as the vice subak head (petajuh), the secretary (penyarikan), the treasurer (petengen or juru raksa), the messenger (kasinoman), special helper (saye) and the heads of the sub-subak groups. Bigger subak are divided into sub-groups, called munduk. Munduk may have a separate inlet from the subak main canal. A munduk usually comprises an average of 20 to 40 farmers.

Every munduk is headed by a pengliman who receives direct orders from the pekaseh and is responsible for all matters related to the munduk. As a sub-group of the subak, the munduk has to follow the subak rules and regulations. However, certain organisational and water management issues can be decided autonomously on the munduk level. The munduk is an important dimension within the subak. Day-to-day cultivation decisions are made on this level and provide the fine-tuning of the subak water and crop management – not always following the subak laws by doing this. The relationship between subak and munduk is to facilitate top down and bottom up information flow.

Members of subak also form an informal group which is called sekaa, in order to make ease a certain working activity on the rice field by working together on a certain field and certain activity. For examples: sekaa numbeg (for land cultivation), sekaa jelinjingan (for water tunnel maintenance), sekaa sambang (for water and pest surveillance), sekaa mamulih (for seed plantation), sekaa majukut (for plants surveillance), sekaa manyi (for harvest work), sekaa bleseng (for carrying paddy to the barn). These sekaa may recruit workers outside subak members. The code of work in these sekaa is simple, “I scratch yours you scratch mine.”