By /

Case study · Sewage pumping

Sewage lifting station & force main hydraulic study: Shuja Island, Abu Dhabi

Steady-state hydraulic analysis of a sewage lifting station and a 710 m HDPE rising main for the Shuja Island development in Abu Dhabi. The study confirms the pump selection and checks self-cleansing velocities across water level and roughness cases.

Client
Presidential Court

Location
Shuja Island, Abu Dhabi

Scope
Pump selection, force main hydraulics, velocities

Tools
EPANET

Criteria
Velocity 0.75–3.0 m/s · pumps within operating range

≈ 710 m

Rising main to the existing sewer

2 × OD110 → OD160

Twin HDPE mains joining into one

1 duty + 1 standby

Submersible sewage pumps

0.72–1.89 m/s

Force main velocity range

The challenge

Keeping a small rising main self-cleansing

The rising main runs about 710 m over a high point before discharging to the existing sewer. Twin OD110 HDPE mains join into a single OD160 main near the end. Velocities had to stay high enough to prevent solids settling, but within the 3.0 m/s limit, as wet well levels and pipe roughness change over the asset life.

Rising main ground and invert profile
Ground and pipe profile along the rising main

Our approach

Hydraulic modelling

  1. Wet well modelled as a fixed-level boundary at the high and low operating levels
  2. Twin OD110 and single OD160 HDPE force mains modelled with temperature-derated ratings
  3. New (Ks 0.03 mm) and aged (Ks 0.15 mm) pipe roughness both tested
  4. System curves built for every level and roughness combination
  5. Pump operating points for single and twin pump operation checked against the selected curve
  6. HGL and pressure checked along the route, including at the high point
System curves for the sewage rising main
System curves for the level and roughness cases

Results

Key results

Hydraulic grade line and pressure along the rising main
HGL and pressure along the rising main for each case

Key findings

  • The selected submersible pumps deliver the design flow, with operating points in the acceptable range for single and twin pump operation.
  • Velocities range from 0.72 to 1.89 m/s, well below the 3.0 m/s limit. Only the worst case (low level, aged pipe, one pump) dips slightly below 0.75 m/s.
  • The HGL stays above the pipe along the whole route, including the high point, so the main stays pressurised.
  • The pump and force main arrangement is confirmed as suitable for the design flow.

Working on a similar project?

Share your pump station brief, levels or force main route and we will advise on the right modelling scope.

Discuss your project →
Drainage & stormwater services
Scroll to Top