Springs are the major source of freshwater in many small mountainous watersheds within the Himalayan region. In recent years, their flow rates have diminished, but the reasons for this are not self-evident, and hence this paper reviews the methods to investigate Himalayan springs. The review reveals that chemical and isotope analyses – mostly water dating and stable isotope (e.g., d18O) analyses – could be an appropriate entry point to commence field investigations, because of their potential to map complex spring pathways, including linkages between aquifers.

To sustain growing food demand and increasing standard of living, global water use increased by nearly 6 times during the last 100 years, and continues to grow. As water demands get closer and closer to the water availability in many regions, each drop of water becomes increasingly valuable and water must be managed more efficiently and intensively. However, soaring water use worsens water scarcity conditions already prevalent in semi-arid and arid regions, increasing uncertainty for sustainable food production and economic development.

Freshwater ecosystems are central to the global water cycle, in local generation of freshwater flows, and the healthy functioning and resilience of other ecosystems. Freshwater security depends on healthy ecosystems. Current human threats to freshwater ecosystems include rapid infrastructure development and land-use change, inefficient water use and over-abstraction, and pollutants. These threats, combined with increasing demand for water resources, exacerbate the sustainable development challenge.

Recycling and reuse of treated wastewater are an important part of the sanitation cycle and critical in an environment such as urban India with decreasing freshwater availability and increasing costs for delivering acceptable quality water, often from far distance. This report has been developed as a possible guidance document for the Indian government and gives substantial focus to the financial and economic benefits of wastewater recycling from the perspective of public spending.

Recycling and reuse of treated wastewater are an important part of the sanitation cycle and critical in an environment such as urban India with decreasing freshwater availability and increasing costs for delivering acceptable quality water, often from far distance. This report has been developed as a possible guidance document for the Indian government and gives substantial focus to the financial and economic benefits of wastewater recycling from the perspective of public spending.

We analyse the threats of global environmental change, as they relate to food security. First, we review three discourses: (i) ‘sustainable intensification’, or the increase of food supplies without compromising food producing inputs, such as soils and water; (ii) the ‘nexus’ that seeks to understand links across food, energy, environment and water systems; and (iii) ‘resilience thinking’ that focuses on how to ensure the critical capacities of food, energy and water systems are maintained in the presence of uncertainties and threats.

The Ganges River basin faces severe water challenges related to a mismatch between supply and demand. Although the basin has abundant surface water and groundwater resources, the seasonal monsoon causes a mismatch between supply and demand as well as flooding. Water availability and flood potential is high during the 3–4 months (June–September) of the monsoon season. Yet, the highest demands occur during the 8–9 months (October–May) of the non-monsoon period.

Although the Ganges River Basin (GRB) has abundant water resources, the seasonal monsoon causes a mismatch in water supply and demand, which creates severe water-related challenges for the people living in the basin, the rapidly growing economy and the environment. Addressing these increasing challenges will depend on how people manage the basin’s groundwater resources, on which the reliance will increase further due to limited prospects for additional surface storage development.

The Southern African Development Community’s (SADC) water and energy sectors are under increasing pressure due to population growth and agricultural and industrial development. Climate change is also negatively impacting on the region’s water and energy resources. As the majority of SADC’s population lives in poverty, regional development and integration are underpinned by water and energy security as the watercourses in the region are transboundary in nature. This paper reviews the region’s water and energy resources and recommends policies based on the water–energy nexus approach.

Reliance on rainfall for agriculture and increased climate change and variability pose growing production risks in developing countries. Agriculture in Sub-Saharan Africa is dominated by smallholder farmers who depend mainly on rain-fed agriculture, putting food security at both household and national levels at risk, especially in the event of drought. Investment in smallholder irrigation becomes a priority in developing countries if food security and national development goals are to be met, as their economies are agro-based.

Irrigation has a large potential to increase agricultural output and yield per unit area. However, the long term sustainability increased production, together with degradation of the soils (and associated water bodies) in irrigated areas may be irreparably damaged by inappropriate watering schedules. In Ethiopia, surface and groundwater irrigation has been promoted intensively throughout the country. While many projects focus on individual or scheme level water access, very little is known about the sustainability of irrigation in Ethiopia.