Modelling water-level options for ecosystem services and assessment of climate change: Loktak Lake, northeast India

Water levels within Loktak Lake, an internationally important wetland, are regulated to prioritize hydropower over other ecosystem services. High water levels have impacted ecological conditions, in particular floating vegetated islands. Barrage operation options prioritizing hydropower, agriculture and the lake ecosystem are developed using a lake water balance model. Current hydropower abstractions can be maintained without ecologically damaging high water levels. Enhanced agricultural abstractions reduce levels to meet ecological requirements. The latter could be satisfied without compromising current hydropower and agricultural abstractions. An integrated option shows it is largely possible to balance hydropower and agricultural abstractions with wetland water-level requirements. Sustainability of barrage operation options is assessed under climate change scenarios. Higher monsoon precipitation and river flow can be accommodated. Larger dry-season drawdowns impact most barrage operation options, especially the integrated option. Results demonstrate the requirement to consider current and potential future climatic conditions when developing wetland water-level management plans.