Total dynamic head

Pumping water level below ground, metres

That level is the dynamic (pumping) level from a yield test static level only (no yield test yet)

TDH must use the dynamic level. A static-only figure understates lift by the drawdown.

Delivery point elevation above ground at source, metres

Elevation data source survey-grade measurement map or DEM interpolation assumed hand-held GPS

The guide prohibits hand-held GPS elevations for design. Survey accuracy under 1 metre is required.

Residual pressure head required at delivery, metres

Design flow, cubic metres per hour

Pipe length, metres

Pipe internal diameter, millimetres

Internal bore from the manufacturer datasheet. Nominal DN is not the bore; HDPE sizes are outside-diameter based.

Pipe material concrete smooth ductile iron lined ductile iron unlined galvanised steel hdpe pvc

Roughness coefficient basis design value (accounts for ageing) new-pipe value