Laying of Primary Trunk Mains for Lagos Water Supply

CLIENT
Lagos State Water Corporation, Ijora, Lagos

FINANCING
World Bank, Consortium of French Commercial Banks, and Lagos State Government

COST
DM 131m

PROJECT PERIOD
• Review of contract documents and assistance during award of contract: 1988 – 1989
• Production of construction drawings: 1989
• Construction supervision: 1989 – 1991

TECHNICAL DATA
• Total length of pipeline = 53.4 km, comprised of
o ND 200 mm steel pipes = 19.3 km and
o ND 800 mm to ND 1,600 mm ductile iron pipes = 34.1 km

PROJECT COMPONENTS
• Review of contract documents and construction drawings
• Evaluation of usability of long-procured steel pipes on hand

PROJECT DESCRIPTION
This project was carried out in joint venture with ENPLAN Group. The project was aimed at improving water supply to metropolitan Lagos by laying primary trunk mains consisting of ND 2,000 mm steel pipes for a distance of 19.3 km, and other pipe diameters ranging from ND 800 mm to ND 1,600 mm for a distance of 34.1 km.

Before the construction started, CKW reviewed the contract documents and then evaluated the usability of long-procured exposed steel already on hand. These efforts helped to ensure the success of the entire project.

The laying of such large pipes in a built-up area such as Lagos results in traffic disruption. To minimize traffic congestion, planning was an integral part of the project. Road diversion signs had to be planned in advance before the actual construction on site.

The minimum trench depth for ND 2,000 mm pipe was greater than 3 m.
For Lagos sub-grade, which is sandy in some places, planking of trenches was very important. The high water table in the lower part of the project area made the project very challenging, but it was carried out with great success.