Ma'in
Trunk Line

Transmitting Water Across
the Ma'in Valley

The Ma'in Trunk Line is a large-diameter water transmission pipeline constructed by CEC to connect source works near Wadi Ma'in — a dramatic valley southwest of Amman known for its steep terrain and natural hot springs — to the distribution network serving the capital. The project was delivered for Miyahuna, the utility company responsible for water supply in Amman, working in coordination with the Water Authority of Jordan.

Trunk mains of this scale form the backbone of Amman's water supply system, carrying treated water over long distances from source and treatment works to the reservoirs and distribution zones that ultimately serve households and businesses across the city. The Ma'in alignment is distinguished by its terrain: the pipeline route descends and ascends through the steep valley topography characteristic of the western escarpment overlooking the Dead Sea basin, requiring careful hydraulic design to manage the resulting pressure variations along the line.

CEC's delivery of the Ma'in Trunk Line drew on our First Grade Water and Sewerage classification and our extensive experience laying large-diameter pipelines across Jordan's varied terrain — from the flat plains of the Jordan Valley to the steep wadi crossings of the central highlands. The result is a transmission asset built to operate reliably for decades, supporting Amman's continued growth.

Engineering Challenges of Valley-Terrain Pipeline Routing

Routing a large-diameter trunk main through the Ma'in valley terrain presented a distinct set of engineering challenges:

• Steep elevation changes: The pipeline alignment traverses significant elevation differences between source works and the Amman distribution network, requiring the line to be designed in pressure zones to keep operating pressures within safe limits for the pipe material at every point along the route.
• Booster pumping station integration: Sections of the alignment required booster pumping stations to lift water across higher ground, with civil works for pump houses and the mechanical and electrical installation of pumping equipment coordinated as part of the pipeline programme.
• Pipe-laying on steep slopes: Trenching, pipe-laying, and backfilling on the valley's steep gradients required specialised excavation sequencing, slope stabilisation measures, and careful management of plant access on terrain unsuitable for conventional trenching methods.
• Thrust and anchor block design: Changes in pipeline gradient and direction along the valley route generated significant thrust forces at bends and tie-ins, requiring reinforced concrete anchor and thrust blocks sized to the specific hydraulic conditions at each location.

Scope of Work

CEC's construction scope on the Ma'in Trunk Line covered route surveying and trench excavation across varied valley terrain; supply and installation of large-diameter transmission pipe with all fittings, valves, and air-release points; construction of thrust and anchor blocks at bends and gradient changes; civil works and mechanical installation for booster pumping facilities along the route; pressure testing, disinfection, and commissioning of completed sections; and tie-ins to the existing distribution network in coordination with Miyahuna's operations team to maintain continuity of supply to Amman during construction.

Quality & Safety on Trunk Main Construction

As a primary transmission asset for Amman's water supply, the Ma'in Trunk Line was built to exacting quality standards: every pipe section underwent jointing inspection and pressure testing before backfill, and the completed line was disinfected and flushed in accordance with Miyahuna's commissioning protocols before being brought into service. On the steep valley sections, CEC's site teams maintained dedicated slope-safety supervision throughout excavation and pipe-laying operations, reflecting the elevated risk profile of construction on difficult terrain.