ENVIRONMENT - OTHER WORKS

An exceptional flash flood of the Gongola river caused erosion for several kilometers along the right bank upstream from the Numan bridge site jeopardizing large cultivated areas and the stability of the north abutment of the bridge and electric power distribution pylons. 

To preserve the natural environment and to eliminate the above dangerous situation the right bank of the river has been restored, reshaped and protected by gabions.

Preliminary study and final design (1990) for the Federal Ministry of Works and Housing (F.M.W.H.) - Nigeria. 

Odo Kala gorge has a gully erosion on a large area produced by the stream running on soils having dis-homogeneous characteristics (rocky blocks inside limes and sandy materials).

Various solutions have been studied looking to the technical/economical aspects.

Among such solutions the one which has been chosen provides for the stream realignment and the control of the longitudinal stream profile consisting in the introduction of protected jumps to reduce the water velocity. The solution provides also for the reshaping of the gully area and the reduction/control of the drainages entering laterally in the gully to avoid future erosion.  All such interventions provide for environment restoring and maintenance.

Preliminary and final Design (1991) for the Federal Ministry of Works and Housing  (F.M.W.H.) – Nigeria.