Rioseco

As of September 1, 2026, Rioseco is filled to 75.0% of its total capacity, holding roughly 3 hm³ of water out of a maximum 4 hm³. At this level the reservoir is within its normal operating range.

Over the most recent week on record the fill level has held broadly steady (+0.0 pts), and it is 25.0 points below its level on the same date a year earlier.

Across the readings we hold for Rioseco — 418 data points between September 4, 2018 and September 1, 2026 — the level has ranged from a low of 50.0% (September 4, 2018) to a high of 100.0% (October 30, 2018). On average the reservoir is fullest around June and at its lowest around September.

It is operated by Cantábrico Occidental. It lies within the Cantábrico Occidental basin at 0.000°N, 0.000°E.