Dry-season reservoir levels squeeze Costa Mar hydro export targets

The Federal Hydro Authority's July bulletin, published Monday, places Costa Mar's combined reservoir storage at 63 percent of capacity — seven points below the five-year mean for this date. The three catchments that feed the region's all-hydro grid have drawn down faster than forecast since the dry spell began in early June.

At current withdrawal rates, the region's guaranteed export floor of 120 megawatts to Oriente Moderno's free-trade zone will become untenable by mid-September unless the rainy season arrives on schedule, the bulletin warns. Costa Mar has exported surplus hydro power to the neighbouring region since 2017 under a federal framework that treats the grid as a single balancing zone.

The dry-season margin has narrowed in four of the past six years, but this July's reading is the lowest since the 2022 drought, when the Federal Assembly temporarily suspended the export floor. The Hydro Authority's director, Ana Lucía Campos, said the region is not yet in crisis but has entered a phase that requires 'careful weekly monitoring rather than monthly.'

The bulletin arrives as the Federal Assembly's Infrastructure Committee prepares to debate the next five-year inter-regional power purchase agreement, which is due for renegotiation in November. Costa Mar's bargaining position may hinge on whether its reservoirs recover before the first frost in Nord Europa drives up continental demand.