Today marks the 20th annual World Water Day, an event centered on increasing recognition of the importance of freshwater and advocating for the sustainable management of the world’s freshwater resources. This year’s World Water Day is dedicated to the theme of international water cooperation and is coordinated by UNESCO in collaboration with UNECE and UNDESA on behalf of UN-Water.
It is no surprise that issues of water, agriculture, and food security are inextricably linked. Irrigated agriculture is one of the major consumers of groundwater worldwide. As we continue to discuss ways to increase agricultural productivity and feed the world’s growing population, the issue of sustainable groundwater use will play a vital role. A recent article in Hydrogeology Journal looks at what happens when an area’s groundwater resources are shared by farms of varying size.
When water is a common resource in an area, farmers’ private decisions regarding water use can often be inefficient and wasteful – the age-old tragedy of the commons. But is this problem exacerbated when small farms and large farms are drawing from the same groundwater? Groundwater Pumping by Heterogeneous Users, co-authored by Alexander Saak of IFPRI and Jeffrey M. Peterson of Kansas State University, examines the relationship between heterogeneous farm size and groundwater use intensity and efficiency. The paper seeks to answer the questions: How does the distribution of differently sized farms in an area impact efficient water use? And how do water management policies impact groundwater distribution and farmer welfare?
The authors analyze these questions using an example of an aquifer that is used to irrigate farms of unequal size. The paper examines two scenarios: first, that in which small farms supplement their agricultural incomes with off-farm activities and second, that in which farming is the sole source of income for the small farmers.
The results find that smaller farms tend to view the water as more of a common resource and therefore tend to pump groundwater faster, while larger farms tend to view the groundwater as a more private resource, since they have more area from which to pump. Thus, policies aimed at reducing inequalities in farm size may have unintended impacts – by attempting to reduce unequal farm size in an area, policies may actually worsen the common resource problem since small farms have a tendency to pump groundwater more quickly and inefficiently.
When looking at social welfare, the authors find that in many cases, inequality of farm size in an area may actually increase social welfare by reducing the tragedy of the commons problem. Additionally, smaller farms may gain a strategic benefit from their larger neighbors because of the potential to “poach” more groundwater from these larger plots. Finally, the authors note that a common resource such as groundwater may provide a vehicle for income transfer from higher income (larger) farms to lower income (smaller) farms. Thus, having unequal farm sizes in an area may not necessarily reduce social welfare; on the contrary, under some conditions, it can actually improve welfare.
The paper concludes with the suggestion that groundwater management policies can have the most impact on in regions populated with small farms, as is the case in many developing countries, since small farms’ water use tends to be more inefficient.