Who we are

Anchored in Switzerland and internationally active, WALO is managed as a family business in the 4th and 5th generation. For over 100 years, WALO has focused on the combination of consistency and innovation.


What we do

WALO is active as an innovative total solutions company in all markets of the construction industry. The family-owned company has established itself as a reliable partner in the construction industry and infrastructure projects in Switzerland and worldwide with its decades of experience and the permanent development of sustainable as well as economical solutions.



We have successfully implemented many challenging projects. Therefore, we proudly let our references speak for our work.



Whether residential, industrial, healthcare, outdoor or for sports and leisure facilities - seamless floor coverings have to meet a wide variety of requirements on a permanent basis.



Good buildings and thus satisfied customers require precise construction work. All our employees, from unskilled workers to engineers, play a key role in ensuring that we achieve this goal time and time again.


Dredging KW Mapragg

Walo Bertschinger AG was commissioned by the Sarganserland power plant to dredge sediments from a water depth of up to 50 meters in the Mapragg reservoir, Tamina Valley near Bad Ragaz.

Project description

Walo Bertschinger AG was commissioned by the Sarganserland power plant to dredge sediments from a water depth of up to 50 meters in the Mapragg reservoir, Tamina Valley near Bad Ragaz.

The Mapragg compensating reservoir was put into operation in 1977. Due to the ongoing permanent sediment inflow, sediments have formed in front of the dam wall, rising up to the threshold level of the bottom outlet.


Special features

During the AVOR phase from December 2017 to the start of construction on May 2, 2018, it was necessary, among other things, to provide suitable dredging equipment that could meet the requirements set. Since no suitable plant could be procured on the construction machinery market, it was built by WALO on its own. The plant had to be designed in such a way that it could reach an excavation depth of 50 meters. The excavation was carried out by a grab with the considerable size of 5 m³. The dredged material then had to be sorted on the plant. While material fractions smaller than 8 mm were pumped to the dam via a floating pump line and discharged into the Rhine through the pressure tunnel of the power plant, the coarse material (wood, stones) had to be disposed of by land.


High demands were placed on the plant control system, which was also built and programmed by Walo. The grab had to be controlled in such a way that the target dredging depth was maintained even when the lake level fluctuated (up to 13m per day). Power was supplied to the plant from a connection at the power station, where 20,000 volts were made available. This voltage was conducted to the plant via a floating line and fed into a transformer stationed on it, from which the plant components were supplied with power.

WALO_Wasserbau Nassbaggerung Mapragg 3
WALO_Wasserbau Nassbaggerung Mapragg 4
WALO_Wasserbau_Nassbaggerung KW Mapragg_2

Walo Bertschinger AG
Bächliackerstrasse 10
4402 Frenkendorf


Hydraulic Engineering

Construction sum
approx. CHF 1 million
Kraftwerke Sarganserland AG
Construction management
Axpo Power AG
Dredging quantity: 50'000 t
Share page

Contactez nous

Nous vous remercions de l'intérêt que vous portez au groupe WALO et nous serons heureux de répondre à toutes vos questions.

© 2024 Walo Bertschinger. All rights reserved.