First it has to be asked why a document concerned with the water implications for food security chooses to concentrate its recommendations on water supply and sanitation. No doubt farming communities make multiple use of locally accessed water, but this is hardly a food security issue.
Second, rather than a generic description of water use in agriculture (for which the 2007 Comphrehensive Assessment was produced anyway), a more pointed examination of the water variable in the accepted definition of food security would be welcome.
Finally, the references to groundwater in section 1.2.2 really needs to take account of the authoriative FAO work on the partition of surface water and groundwater sources for irrigation (Siebert, S., Burke, J., Faurès, J.-M., Frenken, K., Hoogeveen, J., Döll, P., Portmann, F.T. (2010): Groundwater use for irrigation - a global inventory. Hydrology and Earth System Sciences, 14, 1863-1880) and the subsequent update of the Global Map of Irrigation Areas (Version)
Jacob Burke