Lužická Nisa, Jablonec n.N, improving the flood protection of the city by flood passing through the Mšeno dam

Country: Czech Republic
Year: 2010
Customer: Poyry Environment PLC + Valbek LLC +AZ Consult LLC
Povodí Labe, state entreprise
Category: Weir construction and navigation, Flood protection, Project management

Elevation level of the overflow – 516,80 – 517,30 m a.s.l.
Weir crest length – 13,30 m
Elevation level of the crest gate pillars in the Bílá Nisa River channel – 518,00 m a.s.l.
Elevation level of the broad base terrace bottom – 516,22 – 517,64 m a.s.l.
Broad base terrace length – 97,00 m
Broad base terrace elevation – 14,80 promile
Broad base terrace depth – 0,90 m
Q50 = 29,8 m3/s

Controlled section at the inflow into the Pasecká gallery – 3,3 x 2,1 m
Controlled section at the flow – 2,1 x 1,85 m

The Mšeno dam was constructed at the beginning of the 20th century on the Mšenský Brook which passes through the Jablonec nad Nisou city and inflows into the Lužická Nisa River. From the very beginning the dam included also water transfers from the Lužická Nisa and Bílá Nisa catchments, the purpose of which is to protect the urban area against the damaging impact of floods by diverting the natural flood flows above a certain harmless flood level into the dam reservoir by a system of underground diversion canals.

The aim of the suggested adjustments was to reach a more favourable division of flood flows on the diversion objects on the Lužická and Bílá Nisa Rivers. The flood protection zone was expanded up to a 100-year flood level on the Lužická Nisa River and up to a 50-year flood level on the Bílá Nisa River. The project team focused on the proposal of the division object on the Bílá Nisa River.

Responsible for the technical solution proposal in the scope up to construction permit, co-ordination of the project team in relation to the physical modelling of the proposed adjustments, static assessment, co-ordination with the mechanical and electrical parts.