Adapting to Climate Change: Assessing the World Bank Group ...

CHAPTER 3CLIMATE VARIABILITYcost recovery, in general they were unable to boost recovery to levels sufficient to coveroperation and maintenance, imperiling long-run efficiency and sustainability.Efficiency in Water Use3.7 Water efficiency is a key aspect of adaptation in irrigation projects. About halfthe irrigation projects tried to increase water efficiency, but there was littledocumentation or measurement of impacts. However, additional information hasbecome available on a set of projects in China 20 that place measurement of actual waterconsumption at the core of a strategy to promote efficient, high-productivity allocationof water.3.8 Traditional approaches to irrigation efficiency—such as lining the irrigationcanals to prevent leakage—can be maladaptive. In many places, water savings aredevoted to expanded cropping, so that total water demand stays the same, or evenincreases. And the apparent water savings often come at the expense of groundwaterdepletion, since what was leakage to the irrigation operator is recharge from theviewpoint of the well owner.3.9 The core innovation of the Chinese projects is to use satellite-based measures ofcrop evapotranspiration (ET) to measure actual water use. ET represents the loss ofwater by the irrigation system to the atmosphere, as opposed to withdrawals of water,some of which flow back into the canals or into groundwater. The projects set upsystems to efficiently allocate water, using ET to monitor farmers’ compliance. At thesame time, the projects introduced extension services, drip irrigation, and other waterand soil management techniques, and alternative, higher value crops, so that farmerscan boost incomes while maintaining water use at sustainable levels.3.10 These projects may provide new approaches to the long-standing, politicallychallenging problem of promoting efficient and equitable water allocation and use atthe level of the local water users’ association, watershed, or river basin. These are areasin which the Bank has been active. IEG’s water evaluation (IEG 2010b) found thatprojects with water users’ association goals established them only about half the time,but three-quarters of those established were well functioning when the project closed.In contrast, limited evidence from Bank engagement with the creation of river basinorganizations suggests that it is easier to establish them than to ensure theirsustainability. An ongoing DPO in Mexico, aimed at adaptation in the water sector, triesto highlight the importance of river basin management and bolster the strength andplanning activities of river basin councils and organizations.34