CPHEEO compliance
Check every junction and pipe against the CPHEEO 2024 manual and the March 2023 addendum, choose between 17 m and 21 m, and export the result as a CSV for your DPR.
Report > CPHEEO Compliance... checks the last run against Indian design norms: residual pressure at every junction, and velocity, headloss gradient and diameter on every pipe. It lists only what fails or needs a look, because that is what goes into a DPR's remarks column. It needs results, so run the analysis first.
The documents behind the numbers
| Short name | Document |
|---|---|
| M24 | MoHUA/CPHEEO Manual on Water Supply and Treatment Systems (Drink from Tap), Part A, 4th edition, March 2024 |
| A23 | Addendum to the 24x7 Guidelines, MoHUA letter Z.16025/1/2020-CPHEEO dated 6 March 2023 |
| R13 | MoDWS Manual for DPR of Rural Piped Water Supply Schemes, February 2013 |
Each threshold in the window shows its clause and page beside it. The engineer of record owns these numbers: every one can be edited, and an edited number is marked edited on screen and in the CSV.
Minimum residual pressure
Residual pressure is the pressure left at the ferrule while water is being drawn. Pick a Rule set for the kind of town, then the pressure choice within it. Tanks and reservoirs are not checked: they have no ferrule.
CPHEEO 2024 urban (Class I and II cities). M24 gives the range 17 to 21 m (s.2.10.2 p.58, Table 2.7 S.No.10 p.77): 17 m is the minimum, 21 m the target. A23 (March 2023) adopts 21 m flat.
| Choice in the window | Minimum residual pressure | Source |
|---|---|---|
| Minimum 17 m (M24) | 17 m | M24 s.2.10.2 p.58; Table 2.7 S.No.10 p.77; s.12.8.2 p.694 (17 to 21 m) |
| Target 21 m (M24 upper end, A23) | 21 m | M24 s.2.10.2 p.58 (upper end of 17 to 21 m); A23, 21 m for Class I and II cities |
CPHEEO 2024 urban (other cities). M24 gives the range 12 to 15 m (s.2.10.2 p.58, Table 2.7 S.No.10 p.77): 12 m is the minimum, 15 m the target. A23 s.2.3 adopts 15 m.
| Choice in the window | Minimum residual pressure | Source |
|---|---|---|
| Minimum 12 m (M24) | 12 m | M24 s.2.10.2 p.58; Table 2.7 S.No.10 p.77 (12 to 15 m) |
| Target 15 m (M24 upper end, A23) | 15 m | M24 s.2.10.2 p.58 (upper end of 12 to 15 m); A23 s.2.3 p.1 |
Rural (JJM / A23). Minimum terminal pressure at the ferrule. R13 states the same numbers as 7 m single storey and 12 m double storey.
| Choice in the window | Minimum residual pressure | Source |
|---|---|---|
| 7 m, no flow control valve | 7 m | A23 s.4.12.3 p.6; R13 s.9.11 |
| 12 m, with flow control valve | 12 m | A23 s.4.12.3 p.6; R13 s.9.11 |
Legacy 1999 storey norms. Kept for comparison with older DPRs. Not a current norm. The window marks it Superseded (quoted in M24 Table 2.7 remark p.77).
| Choice in the window | Minimum residual pressure | Source |
|---|---|---|
| 1 storey, 7 m | 7 m | CPHEEO 1999, quoted in M24 Table 2.7 remark p.77 |
| 2 storeys, 12 m | 12 m | CPHEEO 1999, quoted in M24 Table 2.7 remark p.77 |
| 3 storeys, 17 m | 17 m | CPHEEO 1999, quoted in M24 Table 2.7 remark p.77 |
| 4 storeys, 22 m | 22 m | CPHEEO 1999, quoted in M24 Table 2.7 remark p.77 |
Minimum and target: the 17 m or 21 m choice
M24 s.2.10.2 (p.58) says the residual nodal pressures "shall be 17-21 m for Class I and II cities and 12-15 m for other cities", and Table 2.7 S.No.10 (p.77) repeats it for the ferrule at the highest node. PipePilot reads the lower end as the minimum a junction must meet and the upper end as the target: it starts on Minimum 17 m (M24) and counts the junctions that meet the minimum but not the target, without failing them. The 2023 addendum (A23) sets a flat 21 m; Target 21 m (M24 upper end, A23) judges every junction against it.
- Use the 21 m target as the minimum when the scheme follows the 24x7 guidelines and their 2023 addendum, for example a 24x7 project in a Class I or II city.
- Use 17 m when the approving authority accepts the manual's range and no 24x7 condition applies.
- When in doubt, ask the approving authority which document governs, and run both: a network that passes at 21 m also passes at 17 m.
- The CSV records which choice you made, with its clause, so a reviewer never has to guess.
Pipe checks and the advisory upper pressure
These apply in every rule set. A breach is a warning, never a failure, because a pipe outside these limits may still be the right design (a short dead-end at low velocity, for example).
| Check | Limit | Source | Note |
|---|---|---|---|
| Advisory upper pressure (PRV setting) | 21 m | M24 s.12.2.5 p.681 and s.12.14 p.721 | No current document states a maximum residual pressure. PRVs are set to reduce residual pressure to 21 m, so this is advisory. |
| Minimum velocity (self-cleansing) | 0.6 m/s | M24 s.6.6(i) p.292; M24 s.12.11.4(7) p.706 | 0.4 to 0.6 m/s recommended, down to 0.3 m/s with scouring; not less than 0.3 m/s above 80/100 mm (s.12.11.4(7)). |
| Maximum velocity | 3 m/s | M24 s.6.6(ii) p.292 | 3.0 m/s for filtered water distribution; 2.5 m/s for raw water mains. |
| Maximum headloss gradient | 10 m/km | M24 s.6.6(v) p.292 | |
| Minimum pipe diameter | 100 mm | M24 s.12.11.4(8) p.706 | 100 mm for primary pipes; 80 mm in hilly areas and outside Class I cities. M24 is not internally consistent on this, and every pipe is checked because the model does not mark which are primary. |
Velocity is judged on the highest velocity the pipe reaches in the evaluated hours. A pipe closed for the whole window is skipped. Models in US units are converted to metres and m/s before checking, and the window says so.
Run the check
- Run the analysis. For a 24 hour run, the check can use the peak hour or the whole day.
- Open Report > CPHEEO Compliance...
- Choose the Rule set and the pressure choice.
- Choose Peak hour (the hour of greatest total junction demand) or Worst over run (the worst value at every junction and pipe over all reported hours). If several hours tie for the peak, the window says so and uses the first; Worst over run covers them all.
- Tick Skip zero-demand junctions to leave out nodes such as pump suction points that serve no one.
- Read the table: failures first, worst shortfall at the top. Zoom to finds the object on the map, and Explain gives plain-language reasons for a junction's pressure: the pipe that loses the most head on the way from the source, how high the junction sits compared with the rest, and its demand at that hour. It is a pointer for where to look, not a full analysis.
- Tick Colour map by compliance to paint junctions and pipes green, amber or red. Closing the window removes the colours.
The chips at the bottom count junctions that pass, warn and fail, and pipes that pass and warn. If you edit the model after the run, a banner asks you to rerun before relying on the result.
Edit thresholds
Press Edit thresholds to show every number with its source. Type a new value to change it; Reset to published values puts the rule set back. A threshold whose clause has not been verified against the page is badged unverified threshold. Every preset threshold is marked verified.
Export the compliance CSV
Press Export CSV at the bottom of the window. The file is named after the network, for example esr-town-zone-compliance.csv, and opens in Excel. It is built to survive being pasted into a DPR annexure without the window beside it:
- Header: the model title, when the check ran, the rule set and whether it is current or superseded, peak hour or worst over run, the peak hour itself, and the units (with a note when converted from US units).
- Thresholds: every limit with its value, unit, source clause, whether it is verified, and whether you edited it.
- Findings: one row per failure or warning: Junction or Pipe, ID, verdict, the check, the value, the limit, the shortfall in metres, and the hour.
Related design values
These are quoted in the help and in Project > Allocate Demands..., not checked by the window: 135 lpcd below 10 lakh population, 150 lpcd at or above, at the consumer end plus 15% losses (M24 Table 2.4, s.2.8.2.3 p.39); JJM rural 55 lpcd. Peak factor 2.5 urban and 3 rural (M24 Table 2.7 S.No.7 p.76). See Demand allocation.