# Argentina Los Nihuiles hydroelectric royalty dispute

> Live situation record from CLSTR: https://clstr.news/situations/argentina-los-nihuiles-hydroelectric-royalty-dispute
> Updated: 2026-09-11T10:59:08.000Z. Sources: 20. Developments: 2.

The legal dispute over hydroelectric royalties from the Los Nihuiles Complex on the Atuel River began with a lawsuit by the province of Mendoza against the National Executive Power. Mendoza sought the “absolute and irreparable nullity” of a 1973 decree that transferred 50 percent of the royalties to the province of La Pampa. In late August 2026, the Supreme Court of Argentina ordered La Pampa to be summoned to the proceedings to issue a statement regarding the litigation.

By mid-September 2026, the dispute reached a resolution through executive action. President Javier Milei signed Decree 982/2026, which repealed the 1973 military-era decree. Under this new regulation, Mendoza will receive 100 percent of the royalties generated by the dam. Mendoza Governor Alfredo Cornejo characterized the decision as a “historical achievement” that aligns with legal precedents and would facilitate increased investment in local infrastructure and upcoming bidding processes.

La Pampa Governor Sergio Ziliotto strongly condemned the measure, describing it as a “theft of resources” and linking the decision to the long-standing dispute over the Atuel River's flow. He announced that La Pampa intends to challenge the decree through judicial channels, while local political figures have called for the resignation of presidential spokespeople in protest. Supporters of the decree, including Deputy Luis Petri, argue the change aligns with Supreme Court rulings that associate royalty rights with the location of the energy source.

## Claims

- Promulgated Decree 982/2026 to repeal Decree 1560/73. (corroborated by 4 sources)
- Assigns 100% of hydroelectric royalties from the Los Nihuiles complex to Mendoza. (corroborated by 4 sources)
- The Governor of La Pampa characterized the decree as a robbery and announced legal action. (corroborated by 3 sources)
- The Governor of Mendoza celebrated the measure as a restoration of legal rights. (corroborated by 2 sources)
- Defended the decree, stating that collecting royalties for energy generated in Mendoza is justice, not theft. (single source)
- Unifies the regulatory framework for the bidding process of the Los Nihuiles hydroelectric complex. (single source)
- Previous rulings in 2003 and 2009 validated the criteria that royalties belong to the province where the source is located. (single source)

## Timeline

### 2026-09-11: Mendoza awarded full Los Nihuiles royalties by Milei decree

President Javier Milei issued a decree granting Mendoza 100% of the Los Nihuiles hydroelectric royalties, ending a 50-year split with La Pampa and sparking a legal and political dispute.

14 sources. https://clstr.news/cluster/mendoza-to-receive-100-of-los-nihuiles-hydroelectric-royalties

### 2026-08-27: Supreme Court summons La Pampa in Los Nihuiles royalty dispute

The Argentine Supreme Court has summoned La Pampa to join a lawsuit filed by Mendoza seeking $67,338 million in disputed hydroelectric royalties from the Los Nihuiles Complex.

6 sources. https://clstr.news/cluster/supreme-court-summons-la-pampa-in-los-nihuiles-royalty-dispute

---
Cite as: Argentina Los Nihuiles hydroelectric royalty dispute. CLSTR, https://clstr.news/situations/argentina-los-nihuiles-hydroelectric-royalty-dispute