The article provides a justification for the need to develop requirements for hydraulic characteristics of water and sewer pipes with internal deposits, that are absent in current regulations. The absence of such requirements leads to a change in the actual inner pipe diameter, flow rate and pressure losses, higher energy consumption of the pumping equipment.Purpose: To develop quantitative requirements for residue layer thickness on the inner surface of exhausted water and sewer pipes to substantiate their decommissioning.Methodology/approach: The quantitative method is used to assess the pipe operation efficiency according to the hydraulic criterion with the analysis of their hydraulic potential.Research findings: Quantitative values are proposed for the operational efficiency of exhausted pipelines according to which the residual pipe operation is determined to justify their decommissioning. Research findings will allow organizations to make decisions on decommission of exhausted engineering networks.Value: The developed proposals can be introduced in construction rules 31.13330.2021 and 32.13330.2018, justifying the need to decommission exhausted water and sewer pipelines with residues.