Nepal's Core Hydro Problem Is Timing, Not Annual Volume

Claim

Nepal's core hydro problem is a timing problem (when water arrives and when demand and export windows need power), not a simple annual water-volume problem.

Evidence

• WECS River Basin Plans and Hydropower Development Master Plan (2024) documents the strong wet-season concentration of basin flows. The relevant planning quantity is therefore the annual hydrograph—especially dry-season tails—not annual discharge alone.
• The governed operating summaries retain a dry-season hydro band of ~1,100–1,300 MW, monsoon production around ~3,000 MW and export surplus near ~850 MW. The exact series use different scopes and are not a plant-level dispatch ledger, but they show a large intra-annual swing.
• NEA Annual Report FY 2024/25 records dry-season imports alongside annual net exports, a system outcome consistent with the physical timing mechanism.
• NEA Annual Report FY 2025/26 repeats the pattern in a year of record net exports (2,794 GWh): domestic generation fell from 1,991 GWh in Bhadra to 801 GWh in Falgun, and Nepal imported 273 GWh in Falgun while exporting 13 GWh (PDF p.176). Annual surplus did not remove the dry-season deficit.
• A RoR-heavy fleet cannot move monsoon inflow into winter without storage, imports, flexible demand or complementary resources; see Seasonal Mismatch.

Confidence rationale

High for the directional mechanism because official basin planning, the RoR-heavy fleet structure and NEA's seasonal trade outcome point the same way. The seasonal generation bands remain operational summaries rather than a single definitive plant-level series.

Unresolved issues

• Exact month-by-month firm-energy curves need periodic refresh against NEA operational statistics and new plant mix.
• The claim does not specify optimal policy responses (storage vs trade vs demand); it only reframes the physical problem.

Boundary Conditions

• This claim reframes the nature of the problem; it does not say timing is the only constraint. Financing, governance, buildability, and market access also bind.
• It does not say Nepal has "enough" water in an absolute sense — only that annual volume is not the binding constraint relative to seasonal distribution.
• It does not prescribe optimal policy responses (storage vs trade vs demand flexibility); see Storage Is the Clearest Physical Answer to Seasonal Mismatch, Seasonal Arbitrage Trap, and relevant syntheses for solution arguments.

Related

• Seasonal Mismatch
• Basin Discharge Data
• Firm Power