About 130 years ago the first Jura Water Correction brought the precondition for a new delta of the river Aare at the lake of Biel. The enormous efforts shaped the form of the landscape fundamentally and built an overall appearance of the locality of national importance. Away from settlements and traffic, behind the molasse hill lays the Hagneck delta with the hydropower plant in the natural landscape. The historically significant place at the lake of Biel is now being adapted to current requirements, the old overgrown cultural landscape is being enhanced and the existing qualities taken care of. This context is the foundation for the design concept. Nature and landscape are configured and structured in the sense of a landscape park. Nature protection areas, nature preservation areas, recreation areas and working areas build sequences full of suspense between extensively and intensively used and maintained environments. The main focus is on the modeling of the terrain, the spacial sequence of the woods and the views in the landscape near the lake. The greater meaning of the new weir system is its influence to the landscape of the lake of Biel. The vastness of the water surface allows a great impression of the St. Peter’s Island, the vineyards of the left lakeside and the mountain Chasseral. Our goal in the competition was the low and compact appearance of the hydropower plant. Thus the building is excellently embedded in the context of the landscape. The project is one of the first contemporary examples in Switzerland how the landscape of infrastructure facilities is becoming a landscape park for recreation. In this way this project exemplifies the future landscape development in densely populated areas and countries.