Cities do not accept water mains based on a verbal report that the work is done. The as-built record is the formal handoff document that triggers the city engineer review, connection authorization, and ultimately the water system acceptance that allows the developer to obtain occupancy permits. Missing or incomplete as-builts delay that chain of events — and the costs fall on the contractor.
What as-built documentation does a city require for water main acceptance?
City engineers typically require the following as-built documentation for water main acceptance: (1) pipe centerline GPS coordinates at every 100 ft and at every horizontal bend, in the city-specified coordinate system (usually NAD83 state plane); (2) GPS positions and elevations for all gate valves, fire hydrants, air release valves, blow-offs, and service saddles; (3) depth of cover measurements at 100-ft intervals and at all crossings with other utilities or roadways; (4) tie-in documentation showing how the new main connects to the existing system, including the existing main size, material, and elevation at the point of connection; (5) hydrostatic pressure test records per AWWA C600 or C605; (6) bacteriological clearance results (negative coliform samples); and (7) a CAD drawing in the city-specified format showing all of the above data. Most cities have a standard as-built format — request it from the utility engineering department before starting the work.
Every appurtenance on a water main — gate valves, fire hydrants, air release valves, blow-offs, tees, and service saddles — must be located with GPS and documented in the as-built record before backfill. Once the trench is closed, locating buried fittings requires pipe locating equipment, and the accuracy is far less than a direct GPS measurement over an open trench.
| Appurtenance | Data to Record | Timing |
|---|---|---|
| Gate valve | GPS position, top of box elevation, valve size and type, turn direction | Before backfill |
| Fire hydrant | GPS position at center, flange elevation, hydrant size, inlet connection size | Before backfill of lateral |
| Air release valve | GPS position, vault or box top elevation, ARV size, pipe invert at ARV | Before backfill |
| Blow-off | GPS position, blow-off pipe size, blow-off elevation, discharge location | Before backfill |
| Tee | GPS position at center, pipe sizes in all legs, invert elevation | Before backfill |
| Horizontal bend | GPS position at center, bend angle, pipe invert elevation | Before backfill |
| Service saddle | GPS position, service lateral size and direction, tap elevation | Before backfill |
| Tie-in to existing main | GPS at connection, existing main size/material/elevation, new main size/elevation | At connection, before backfill |
Depth of cover requirements for water mains vary by jurisdiction, climate zone, and location relative to traffic. Minimum depths range from 36 inches in warm climates to 72 inches in northern states where frost depth is a concern. The as-built record must include measurements at:
Cover depth is calculated as: finished grade elevation minus top of pipe elevation. Document both the top of pipe elevation (from GPS survey) and the finished or proposed grade elevation at each measurement point. In areas where final grade has not yet been established, note that final cover will be verified after grading is complete.
No city will accept a water main into its system without hydrostatic pressure test results and bacteriological clearance. These records are not part of the GPS as-built, but they are required components of the acceptance package.
Required pressure test documentation per AWWA C600 (ductile iron) or AWWA C605 (PVC):
Bacteriological clearance requires two consecutive negative coliform test results from samples collected at the ends of the new main. The health department or city lab analyzes the samples. Include the lab report in the acceptance package.
Most cities require the as-built record in both PDF and AutoCAD DWG format. The CAD drawing must show the pipe centerline, all appurtenances, depth of cover annotations, and connection to existing mains — overlaid on the approved construction drawings or on the city base map.
Common city-specific requirements to confirm before starting the CAD deliverable:
Sitemark records GPS positions, elevations, cover depths, and test records in the field — assembled into a city-ready as-built package before backfill. Start free.
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