Regulating weir port
The Port Regulier weir is a hydraulic engineering system in the Nidau-Büren Canal and serves to balance the water levels in the lakes at the foot of the Jura and the outflow of the Aare . The height of fall is between 3.0 m at low tide and balanced water level with open weir gates at extreme high tide.
history
Since the first Jura water correction from 1875 to 1878, the water of the Aare from Aarberg no longer flows directly in the old channel to Büren an der Aare , but in the Hagneck Canal to the north-west and at Hagneck into Lake Biel . This means that the three lakes at the edge of the Jura (Bielersee, Neuenburgersee and Murtensee ) can compensate for the often recurring floods of the Aare, and the lower reaches of the river no longer reach as high water levels as in previous centuries. From 1880 to 1887 a barrier was built in the Nidau-Büren Canal , which partially influenced the outflow from Lake Biel.
After major floods have occasionally occurred below the canal since then - especially in the rainy year 1910 - the canton of Bern, with the support of the Swiss Confederation, built below the confluence of the Nidau-Büren Canal and the Zihl , the old outflow of Lake Biel, from 1936 until 1939 the regulating weir at Port . In addition to the five riflemen, it also contains a lock for shipping on the Aare. A road bridge runs over the weir from Port to Brügg .
Todays use
The weir at which the Aare Brügg measuring point is located is controlled from the control center at the Water and Energy Administration in Bern. It regulates the outflow of the water stored in the Jura peripheral lakes, which fluctuates mainly due to the flooding of the Alpine tributaries. According to an agreement between the cantons of Bern, Solothurn and Aargau , the Aare should only carry enough water that a specified maximum flow rate is not exceeded at Murgenthal , which does not yet lead to flooding in the lower reaches of the Aare. In the case of extremely heavy rainfall in the catchment area of the Aare and especially the Emme flowing into it below Solothurn, regulation is not always possible without conflict and in a timely manner, as was shown by a flood on August 8, 2007, in which parts of the city of Aarau and the riparian zones of several villages in the cantons of Solothurn and Aargau were flooded.
The river engineering works of the second Jura water correction were intended to improve the flow conditions of the Aare and the balance between the lakes and thus strengthen the regulating effect of the weir at Port.
On the occasion of the general overhaul of the regulating weir from 1989 to 1992, Bielersee Kraftwerk AG built the Brügg hydropower plant on the north side next to the weir , which has an average annual production of 25 million kilowatt hours since 1995.
Web links
- The regulating weir port
- Brochure from the AWA (Office for Water and Waste in Bern) on the regulatory weir (PDF file; 873 kB)
Coordinates: 47 ° 7 '8 " N , 7 ° 15' 25" E ; CH1903: 586212 / 218 672