Hi Pashwan, If you have ...

Hi Pashwan,

If you have money to spend you can use ground penetrating radar or other remote sensing method.

But if you want cheaper solution, you can use inverse hydraulics modeling (e.g. by using EPANET/WaterGem) but you need to have flowrate and presure data for several points of measurement. You can also use analytic approach (calculate pipe diameter based on pressure and flow variabales (e.g. simplfied bernoulli or Darcy Weisbach equation).

Another approach is by looking for flowmeter installed. You can find the diamater of the flowmeter or if you know the permanent/average flowrate, you can determine diameter based on flowmeter specs. An example is for 40 m3/h flowrate, the diameter of flowmeter would be around 50-65mm and the pipe would be most likely around 50-65mm as well.

Best Regards,

Alfa