City acceptance of public utility infrastructure depends on as-built drawings that accurately document what was actually installed. A complete, correctly formatted as-built gets accepted in one review cycle. An incomplete or inaccurate as-built cycles through revisions for months, holding up project closeout and bond release.
What is required to document utility as-builts for city acceptance?
Utility as-built documentation for city acceptance requires: field survey of all manhole rim and invert elevations, pipe locations and depths, service lateral locations, and deviations from design. The survey data populates an updated CAD drawing in the city's required format, stamped by a licensed engineer or surveyor. Submittal includes the drawing, data file (DWG or GIS), and any required certifications. Most cities take 2-6 weeks for first review.
The foundation of any utility as-built is accurate field survey data. Data collected after backfill from buried features is unverifiable; data collected during installation is reliable. Develop a habit of capturing as-built data during construction, not at closeout.
For gravity sewer systems, required field data includes:
| Feature | Data Required | Method |
|---|---|---|
| Manhole | Center coordinates (N/E), rim elevation, invert elevation for each pipe | GPS + level |
| Pipe run | Upstream/downstream MH IDs, diameter, material, calculated slope | Computed from MH data |
| Service lateral | Distance from downstream MH, offset from centerline, depth at main, angle | Tape + level or GPS |
| Cleanout | Location coordinates, rim elevation, depth | GPS + level |
| Pipe bend / deflection | Location coordinates, depth at bend | GPS during installation |
| Depth of cover at key points | Surface elevation - pipe crown elevation | Level + rod to pipe crown |
Use the right survey method for each data type. Mixing high-precision elevation data with low-precision horizontal data produces an inconsistent as-built that will fail city review.
Use an RTK GPS rover for manhole center coordinates and key pipe bend locations. Collect positions in the city's required coordinate system — typically state plane with an NAD 83 datum. Accuracy of ±0.03 ft is adequate for plan-view utility mapping. Confirm the city's required accuracy specification before the survey.
For manhole rim and invert elevations, use a digital level set up on a project benchmark (tied to NAVD 88). Accuracy: ±0.005 ft. GPS rover vertical accuracy (±0.03 to ±0.05 ft) is often adequate for rim elevations but may not meet city specifications for invert elevations on tight-grade systems. Confirm the city's vertical accuracy requirement — some municipalities require ±0.01 ft for invert elevations.
Service lateral locations are measured as a distance along the main from the downstream manhole and a perpendicular offset to the left or right. Depth at the main wye is measured with a level and rod. GPS is not practical for laterals because the precision required is in the sub-foot range and the lateral may be in an active trench. Tape and level is the standard field method.
The as-built CAD drawing is a revision of the approved construction drawing, updated to reflect field conditions. Every element that differs from design must be updated and annotated. Elements that were built exactly as designed do not need annotation — only deviations are marked.
Standard as-built drawing requirements from most municipalities:
Most cities process utility as-built submittals through the public works or engineering department. The typical submission package includes:
Submittals that are missing any required element are returned without review — they go back to the front of the queue when resubmitted. Confirm the complete submittal requirements list with the city before preparing the package. Many cities publish their as-built submittal checklist on the public works department website.
For a detailed reference on what city engineers require at project closeout, see our guide on sewer as-built documentation city requirements.
Required data includes: manhole ID, coordinates, rim elevation, invert elevations for each pipe, pipe diameter, material, slope, service lateral locations and depths, and depth of cover at key points. Horizontal coordinates in state plane system and elevations referenced to NAVD 88 are typically required.
Complete, correctly formatted submittals typically take 2-6 weeks. Incomplete submittals that require revision cycles can take 2-4 months. The most effective way to minimize review time is to submit a complete package that meets all city requirements on the first attempt.
Most municipalities require the as-built drawing to be stamped by a licensed civil engineer or land surveyor. Requirements vary — some cities require the contractor's engineer of record; others require a city-approved engineer. Confirm the specific requirement with the public works department before preparing the as-built.
Sitemark logs invert elevations, manhole coordinates, and lateral data in the field during installation — so your as-built is built as you go, not reconstructed at closeout. Start free.
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