Early Medieval Irrigation Systems in the Kathmandu Valley

Evaluating lessons from the past for the future

Evaluating lessons from the past for the future

The Kathmandu Valley has a unique historic irrigation infrastructure of channels (rajkulos), which provide irrigation for cultivation as well as domestic supply by feeding into networks of sunken brick-lined tanks with stone spouts, referred to as hitis. Its origins have been ascribed to the Licchavi Period (c.5th-8th centuries CE). Inscribed stone spouts, small water tanks (jaladroni) and regulations recorded in royal edicts preserved on stone slabs attest to these constructions and provide insights into donative and administrative patterns related to irrigation infrastructure. Confirmed through architectural studies, the Department of Archaeology (Government of Nepal) has excavated and recorded stone-lined rajkulos and terracotta pipelines, which derive much of their supply by tapping into springs, aquifers, groundwater sources and surface runoff with ponds constructed close to hitis to help recharge these systems through rainwater storage. Many of these systems are still in use, but some have become blocked and damaged by unchecked development, as identified during recent post-disaster fieldwork (Coningham et al. 2019), while others have been depleted by the proliferation of groundwater pumps draining natural groundwater. Furthermore, the historic artefacts bearing Sanskrit inscriptions relating to these ancient water constructions are at high risk of damage or unchecked removal due to flooding or repair and construction works, and are therefore in need of comprehensive documentation and analysis. 

Recent collaborative research activities have highlighted that these water systems are not just vestiges of the past but play continued dynamic roles as foci for communities and intangible traditions. Indeed, it has also already been argued that the rehabilitation of rajkulos and hitis could substantially contribute to groundwater recharge if undertaken in suitable locations of the Valley. This workshop will gather experts from philology, archaeology, cultural studies, engineering and conservation to explore pathways for regeneration of these irrigation systems by evaluating how they originated, were constructed and managed historically and then declined, as examplified by lessons learnt from the Dry Zone or Sri Lanka and Tehran Plain or Iran, where multidisciplinary fieldwork has revealed that sustainable and small-scale traditional irrigation systems were more resilient compared with modern mega-infrastructure projects. The rajkulos/hiti system has the potential to mobilise inidigenous design and low-cost alternatives for sustainable water supply within the Valley, integrating physical infrastrucutre and agency management aspects, unlike the current Asian Development Bank mega-infrastructure project to expand reservoirs and divert major rivers at a loan cost of US$170,000,000 (ADB Project 3404-043).

The results and discussions generated during this workshop will enhance the working schedule for upcoming research activities in the frame of a two-year Royal society-British Academy-Royal Academy of Engineering APEX grant "Exploring the feasibility of regenerating Medieval Licchavi Period irrigation infrastructure in the Kathmandu Valley, Nepal" (APX\R1\231178), supported and co-sponsored by the FWF-funded project "Mapping piety, politics and power in Early Medieval Nepa" (FWF V755-G).

Please contact nina.mirnig@oeaw.ac.at if you wish to attend.