Structural and non-structural water management concepts and community participation in managing land and water resources in ancient Sri Lanka
Hydraulic civilization was prominent in Anuradhapura and Polonnaruwa eras till the 13 century Anuradha Senaviratne (1987). Cascade system was identified as the managing land and water systems in dry zone areas Madduma Bandara in 1995. Sustainable system of managing each and every component of the landscape and water resources was discussed in details by P.B. Dharmasena in 2010 and emphasized the community participation in managing these systems identified as “Ellangava”. Abayasinghe in 2018 highlighted the need of restoring the cascade system or the “Ellangava” system of management as a remedy for the unidentified conical kidney deices.
Community participation in land and water management could be identified as one of the successful management strategy practiced in ancient hydraulic civilization in Sri Lanka. Structural and nonstructural land and water management techniques used in the ancient past were based on several hydraulic control systems namely, increase of infiltration by providing detention ponds or depression areas, water quality control by using grass covered areas or constructed wetlands or bio retention areas, increase of flow path to increase the time of concentration and thereby to reduce the flow velocity and the discharge quantity, replenish groundwater aquifers by using structural ponds, grass covered swells etc.
All these ancient water harvesting systems help to retain water not only for human consumption but also for other living flora and fauna allowing retaining the bio diversity. Therefore, ecosystem resilience is well managed at micro scale while development work is carried out by the humans to improve their livelihoods at macro scale. Macro scale development model could be identified as an aggregation of several micro level management systems run by the community.
Micro level geographical units of management or micro catchments are managed by the community and community participation was kept at maximum to manage the land and water resources. This model has been now identified as “Ellangava” management system or cascade management system.
Principle behind the cascade or “Ellangava” system could be identified as a system which used to classify the landscape according to the topographical features and manage natural hydrological functions within those micro level catchments without any disturbances to the valuable ecosystem services. This management system also support ecosystem services and to maintain the resilience while improving the livelihoods of the stakeholders with the community participation.
This principle could be used globally to address the climate change scenarios to improve the land and water management strategies adapted in any country with the community participation to improve the ecosystem resilience as well as the livelihoods of the stakeholders.
Present paper discusses four cases to illustrate the present status of the hydrological controls adopted in Rnamasu Uyana, Segiriya lion rock area, Polonnaruwa ruin city and Udawaththa forest reserve in Kandy.