The Tanes reservoir: kayaking yes, swimming no, and what else you can do on the water

Swimming is banned in the Tanes reservoir, but you can go out without an engine: kayak, rowing, sailing or pedal boats. Boats must be ‘captive boats’ not used in other waters, so you cannot bring your own kayak; Turismo Asturias advertises guided kayak trips. Fishing is allowed with a licence, with some closed stretches.

The Tanes reservoir, between Caso and Sobrescobio, is the only one in the Redes Natural Park where boating is allowed. That doesn't mean anything goes: swimming is banned, so are engines, and the boats that go on the water can't come from anywhere else. What the rules allow, what Turismo Asturias offers today, how fishing works and what was left under the water when it filled.

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What it is and why it was built

Tanes lies between the municipalities of Caso and Sobrescobio, about four kilometres from El Campu and from Rusecu/Rioseco, according to Turismo Asturias. Its main job is drinking water: it supplies much of central Asturias, and it is also used to generate electricity and for industry.

The concession dates from 1970. A resolution published in the BOE in 1985 notes that the reservoir is part of the concessions granted by orders of 16 March 1970 to the Consortium for Water Supply and Sanitation of Central Asturias, today's CADASA, and to Hidroeléctrica del Cantábrico, and authorises enlarging it by raising the dam to elevation 495. Between the two reservoirs, Tanes above and Rioseco below, there is an underground hydroelectric power station, built between 1970 and 1978 according to Wikipedia, whose turbines are reversible: the 1979 BOE resolution that set its conditions provides for them to pump water from Rioseco up to Tanes.

Swimming: no

It is the most frequent question and the answer is clear. Decree 7/2020 of the Principality, published in the BOPA on 16 March 2020, bans swimming in the Tanes and Rioseco reservoirs, including competitive swimming. The rule gives two reasons: disturbance to wildlife and the fact that this is water for human consumption. Turismo Asturias repeats it on its page for the reservoir: swimming is prohibited.

Kayak, canoe and rowing: yes, with conditions

Until 2017 boating was banned on the park's reservoirs. That year an Asturian law opened it up, and the same 2020 decree settled it like this: boating is allowed only on Tanes; Rioseco is excluded. On Tanes, non-motorised boating (rowing, sailing, pedal boats) is allowed and engines, electric or petrol, are banned, except for rescue, police or dam maintenance.

The condition that most surprises anyone arriving with a canoe on the car roof is the one about ‘captive boats’: every authorised boat must be one that has not been used in other waters and that does not leave the reservoir only to come back later. The aim is to keep out invasive species whose larvae stick to hulls. In practice, you cannot bring your own kayak from another river or lake.

The decree also sets limits: initially, no more than 100 individually identified leisure boats and no more than 33 on the water at once, with a seasonal calendar that respects spawning periods. The Asturian Canoeing Federation can authorise up to nine more boats for sports training. Permits for the water itself are issued by the Confederación Hidrográfica del Cantábrico.

For visitors, the way to get into a kayak on Tanes is the one advertised on the official Turismo Asturias page for the reservoir: guided kayak trips, with a link to the company that runs them. Dates and places depend on that boating season, so it is worth asking before you go.

Fishing on Tanes

You can fish with an Asturian licence, but some stretches are closed. The fishing rules for the 2026 season, published in the BOPA on 30 October 2025, close the left bank of the Tanes reservoir until 15 June, from 200 metres downstream of the Coballes bridge to the dam wall. Upstream, the stretch of the Nalón and the Caleao between the Cueva del Boyu bridge, the Puente de Piedra on the Caleao and the Coballes bridge is the Tanes-Caleao preserve, catch-and-release only. The rules change every season: check the current year's.

What was left under the water

Tanes is also the name of the village and parish in Caso that gives the reservoir its name. According to Wikipedia, several of its old quarters were submerged in the 1970s, and with them houses, a furniture factory and the riverside meadows the village lived on. The same encyclopaedia says that hamlets of the neighbouring parish of Coballes also ended up under the reservoir.

What still stands is the church of Santa María la Real, from the 16th and 17th centuries and listed as a site of cultural interest, by the water. Turismo Asturias describes Tanes as a hamlet with many hórreos and paneras, the raised granaries of Asturias, and good views of the reservoir, and notes that you can take a quiet walk along either shore. From the shore, Turismo Asturias points out ducks, waders and herons.

Getting there

You come in on the AS-17, which enters Sobrescobio from Laviana, passes Rusecu/Rioseco and carries on towards Caso; Turismo Asturias gives access to the reservoir from Rioseco along that road. Without a car, the connection is by bus, as explained in the guide to the Gijón–Laviana train; Sobrescobio council publishes the timetable of the Laviana–Tarna line. For the other reservoir, the lower one, with its path and the Casa del Agua, there is the guide to the Rioseco reservoir. And a few kilometres upriver, the Deboyu cave, where the Nalón disappears into the mountain.

Checked

Checked in October 2026 against the Turismo Asturias page for the Tanes reservoir, Decree 7/2020 of the Principality of Asturias (BOPA, 16 March 2020), the fishing rules for the 2026 season (BOPA, 30 October 2025), the 1979 and 1985 BOE resolutions on the Tanes power station and dam, and Wikipedia for the power station and the submerged quarters.