After double checking, it appears the pipe is actually 3 cm.
This is rural Japan and the city recommends this solution so connecting is no problem.
Your responses have confirmed my suspicions. One contractor was quoting a need for 3 pumps.
Follow on questions.
1. With the 3cm pipe gain, what...
Residential building is 350m (1,200') from city water source (clean potable water only)
Elevation change is an increase of 30m (100')
Flow Rate: 10-15 GPM
Power source = Electric
Pipe: 2.5 cm (1") black poly pipe
Climate: Tropical: HI = 28.4 °C | 83.1 °F, LOW: 15.6 °C | 60.1 °F
Tank above...