ABSTRACT
This project aimed to identify and prioritize opportunities for sustainable development of groundwater resources with specific focus on the lowland plains and upland plateaus of Laos. It addressed this aim through three key objectives: (1) establish the potential to develop groundwater for irrigation in key hydrogeological settings in Southern Laos;(2) assess the opportunities that solar-powered pumping technologies may provide smallholder farmers seeking to engage in more profitable, market-oriented agriculture;and (3) enhance the capacity of current and emerging groundwater professionals in Laos. Two areas with promising aquifer development potential were selected in Southern Laos: a drought-prone lowland area underlain by sandstone aquifers in Savannakhet province (Outhomphone district);and a wetter, upland basaltic area on the Bolaven Plateau (Pakxong district). For the first objective, a preliminary hydrogeological assessment was undertaken based on the collation and analysis of existing (limited) data supplemented by data from a network of around 40 to 50 monitoring wells in each district and other hydrogeological measurements collected during two field campaigns. For the second objective, the opportunities for solar-powered groundwater pumping to provide an alternative to conventional grid electricity or fuel pumps was explored through policy analysis and the evaluation of a demonstration project as well as actual field operations. The third and final objective involved a cross-cutting effort to enhance capacity of current or emerging groundwater professionals. For Outhoumphone, where the need for dry season access to reliable groundwater sources is high, the sandstone aquifers present are likely sufficiently replenished but inadequately productive to provide a substantial resource for expanding dry season irrigation. Drillers in the area report well instability, saline water and drilling failure as common technical challenges. With adequate field investigations these challenges may be overcome and supplies for commercial agriculture could become feasible. For Pakxong, where the basaltic aquifers are more productive and reliable, field observations show that more entrepreneurial farmers have already started to develop groundwater for high value commercial crops. There is clear scope to expand irrigation development. Drillers report high success rates for wells and this is supported by the aquifer testing undertaken during this research. Even though policies on solar technologies in agriculture are limited, the solar industry appears to be expanding rapidly, with over twenty solar companies based in Laos;most of which are also servicing the agricultural sector. A demonstration site operated by the National Agriculture and Forestry Research Institute in Vientiane Capital provides firsthand experience of solar pumping and data is emerging on its functioning and performance. Rapid assessments of six solar pumping sites on the Vientiane Plain show that better-off farmers and investors with the means to afford the upfront capital cost are accessing water on demand at effectively little or no marginal cost. Although the situation is evolving rapidly, solar water pumping for agriculture still remains an emerging technology in Laos and hence the long term technical performance, economic viability and potential impacts on the groundwater resources remain entirely unanswered at the present time. A one-week hydro-geophysics training course took place in Pakxong in November 2020 that involved 14 attendees from government agencies and the national university. Training was provided in fieldwork and analysis in new techniques to investigate groundwater using geophysical equipment, site wells, drilling and aquifer testing and aquifer conceptualization. In-situ guidance was provided by in-country team members supported by higher level oversight provided remotely by trainers based in Australia due to travel restrictions associated with COVID-19. The project has also enabled 5 Bachelor, Master and Doctorate students to unde