Chly Rhy Auen

Chly Rhy Auen is a restored Rhine floodplain at Rietheim in the Swiss canton of Aargau. Since 2022 the village has been part of the municipality of Zurzach. A wooden lookout tower stands at the edge of the site and gives a view over the whole wetland. The area belongs to the Aargau floodplain park (Auenschutzpark Aargau).

What is Chly Rhy?

In local dialect the name means "Little Rhine". It was a side arm of the river about 1.5 km long. Around 1920 an embankment cut it off from the main channel. In the 1960s most of its mouth was filled in for a hydropower plant that was never built, and poplars were planted on top. For decades the natural flooding stopped.

The renaturation took roughly eighteen months, and the site opened on 20 June 2015. Today it covers about 35 hectares and is the largest revitalised floodplain on the High Rhine between Lake Constance and Basel. The canton of Aargau, Pro Natura, the utility ewz and the municipality of Rietheim ran the project together.

What will you see?

The scenery shifts with the water level. The river again undercuts its banks, carves side channels and leaves gravel bars and shallow pools. Young willow thickets are replacing the old poplar plantation. This patchwork draws waterbirds, amphibians and insects that depend on habitats the river keeps reshaping.

The tower lets you watch wildlife without walking into the sensitive core of the reserve. Bring binoculars. The floodplain, the river and the wooded hills across the Rhine make good photographs.

How do you get to Chly Rhy Auen?

The tower sits at about 47.609 N, 8.273 E, on the northern edge of Rietheim beside the Rhine, which forms the border with Germany here. The easiest approach is to reach Rietheim or nearby Bad Zurzach and continue on foot or by bike along the river. Several walking and cycling routes follow the Aargau bank, so the visit combines well with a longer outing.

When should you visit?

The area is open all year. Spring and early summer bring nesting season and the busiest bird activity. After snowmelt or heavy rain the water rises and the floodplain looks its most dynamic. Autumn offers softer light and fewer visitors. Keep quiet and stay on the marked paths, since this is a protected natural area.

Frequently asked questions

Where is Chly Rhy Auen? In Rietheim, canton of Aargau, on the border with Germany. Since 1 January 2022 Rietheim has belonged to the municipality of Zurzach.

How big is the site? About 35 hectares, making it the largest restored floodplain on the High Rhine.

When was it restored? It opened on 20 June 2015. In the 1960s the outlet had been filled in for a planned power station.

Can you climb the lookout tower? Yes, the tower is there for watching the floodplain and its wildlife from above. Check current details with the canton of Aargau or the municipality of Zurzach before you go.