Tagus River water management and flow disputes

The proTEJO movement has initiated formal efforts to influence the management plan for the Tagus River basin, demanding that ecological flows and infrastructure such as dams and water transfers be recognized as significant environmental pressures. Spokesperson Paulo Constantino argued that water management should not be a “technical exercise isolated from the causes of the ecological crisis,” citing concerns over groundwater degradation and failures by Portugal and Spain to maintain minimum flows.

Following these demands, environmental organizations proTEJO and ZERO reported that the river has failed to meet the minimum daily water flow agreed upon by Portugal and Spain. Data indicated that between October 2025 and September 2026, there were 14 days where flow fell below the agreed minimum of 1 cubic hectometer per day, including five days of zero flow. These findings contradict previous government commitments to ensure daily regularity, as organizations argue the current water distribution does not fulfill the binding agreement to distribute weekly minimums across all seven days.