Water management in irrigated rice - Rice Knowledge Bank ...

level: the irrigation system, provincial, or nationallevel. Farmers must face the consequences of thesedecisions: they receive less water and have to copewith “imposed water scarcity.” The notion that weshould ask farmers to actively save water so it canbe used elsewhere, such as by industry and cities,is a fallacy. Farmers can be encouraged to voluntarilyreduce water use, for example, by introducingvolumetric water pricing, but this is the exceptionrather than the rule and “enforced water scarcity” isprevalent. Voluntary water savings by farmers forredirected use work well only with properly functioningwater markets. For example, in Australia,rice farmers in irrigation schemes in the Murraybasin can sell their water rights in a water market toother users, such as other farmers who grow highvaluecrops such as fruits (Thompson 2002).Definition 2: to reduce expenditures becauseof reduced income. In water terms, this translatesinto “reducing the use of irrigation water becausethere is less of it.” This type of water savings inagriculture is induced by actual and physical waterscarcity. An example of this situation for farmersis the “enforced water shortage” discussed above.However, an absolute water shortage can also beinduced by natural causes. For example, when seasonalrains have failed to fill up reservoirs or ponds,the amount of water may not be sufficient to keepall rice fields flooded throughout the year. Whenthe reservoir forms part of a large-scale irrigationsystem, reservoir managers usually respond byreducing the “program area” for irrigation: fewerfarmers will receive irrigation water. However, withsmaller reservoirs such as individual ponds, farmersthemselves can decide how to cope with the waterscarcity. They may decide to reduce their land underirrigation or they could decide to “reduce currentexpenditures to allow for future expenditures”: todeliberately save water early in the season to have itavailable later in the season. Farmers can save waterby reducing the amount of irrigation applied to theirfields early in the season. The best way to do this isby reducing the nonproductive outflows seepage,percolation, and evaporation (Chapter 3).Definition 3: to reduce costs to increase profit.In water terms, this translates into “reducing theuse of irrigation water to lower the costs.” Thisscenario is applicable when farmers pay a high costfor water and have the means to reduce their wateruse to increase their profits. There may be plentyof water, but it is relatively expensive (“economicwater scarcity”). In most surface irrigation systemsin Asia, farmers either pay no cost for their water orpay a flat rate (a fixed sum per unit land area), andwater costs cannot be reduced by reducing wateruse. When farmers pump their own water, eitherindividually or collectively, they pay a relativelyhigh price for their water when pumping is fromdeep aquifers and/or when the price for electricityor fuel is high. In this case, water savings byfarmers are a voluntary and deliberate choice oftheir own. The means to save water are the sameas in the scenario above: to reduce irrigation waterto their fields.These examples illustrate that water scarcity isusually imposed upon farmers (either by nature orby decision makers at higher levels) and that savingwater is hardly a voluntary choice (except in definition3). Farmers just have to cope with physicalwater scarcity, and the term “water-scarcity copingtechnology” may be more appropriate than the term“water-saving technology.”10