Environmental-economic accounting for sustainable water planning: A case study of water supply systems in Kazakhstan

Kazakhstan faces growing water-security challenges driven by climate variability, urbanisation, ageing infrastructure, and limited integration of environmental considerations into water planning. This study presents the first application of the System of Environmental-Economic Accounting–Ecosystem Accounting (SEEA-EA) framework to a water resource system in Kazakhstan. Applied to the Astana Reservoir, the primary water source for the country's capital, the framework combined spatial analysis, hydrological modelling, economic valuation, and stakeholder engagement. Four ecosystem services (ES)—water supply, water purification, erosion control, and recreation—were assessed. In 2019, the reservoir supplied 90.3 million m 3 of water, meeting approximately 88% of Astana's demand. Natural purification processes provided an equivalent treatment service of 6.1 million m 3 /year, while catchment ecosystems retained 13,313 t of soil annually. The total annual value of assessed ES was estimated at US$59.7–80.9 million. The study demonstrates how SEEA-EA can support water planning, policy development, and sustainable water governance in Kazakhstan and Central Asia.