Potable Water Distribution
Potable distribution systems convey treated water from a clearwell or reservoir through a pressurized network to consumers. Pressure must remain ≥20 psi at all service connections under fire-flow demand, and velocities are typically held below 5 ft/s to avoid scour and water hammer.
Target industries
Municipal water utility Rural water system Commercial campusRecommended calculation methods
- Hazen-Williams (C ≈ 140-150 for cement-lined ductile iron / PVC)
Key design factors
- Minimum residual pressure 20 psi at fire-flow demand (AWWA M22)
- Maximum velocity 5 ft/s for distribution mains
- C-factor selection for the chosen pipe material + age
- Storage volume sizing for fire flow + emergency reserve
Common pitfalls
- Sizing on pump catalog peak rather than system curve duty point
- Neglecting C-factor decay in long-service mains
- No flushing program → tuberculation reduces effective diameter