GPR Survey in Ahmedabad, Gujarat — Underground Utility Detection

Working inside the pols

The walled city's pols are among the most difficult ground we survey anywhere in the country. Lanes are metres wide, frontages are occupied from early morning, and services have been added, abandoned and re-added over a century without any consolidated record surviving.

Heritage status adds a second constraint. Excavation here is scrutinised, and the argument for surveying before touching the surface is stronger than almost anywhere — an unnecessary trial pit in a protected lane is not a small matter.

Coverage rates that hold on open corridors collapse in this ground. We quote the old city separately rather than folding it into a city-wide average, because pretending the two are the same is how survey programmes overrun.

Chemical estates and what runs beneath them

Naroda, Vatva and Odhav carry a subsurface profile that no residential area produces. Alongside heavy electrical distribution and process water, there are effluent and chemical conveyance lines, some belonging to a common facility, some laid privately by units that no longer exist.

This changes how we report. A probable effluent line is flagged explicitly and separately, because the consequence of breaching one is chemical exposure and a pollution notice rather than a wet trench.

Plot surveys before a shed extension, a machine foundation or a new tank base are routine here, and they routinely find services that the current occupier inherited without documentation.

Riverfront, BRTS and made ground

The Sabarmati riverfront development placed new corridors over reclaimed and engineered fill, which behaves differently from the older alluvium either side of it. Radar response varies across short distances, and calibration has to follow the ground rather than a single assumed velocity.

The BRTS corridors carry their own servicing beneath dedicated lanes, and any crossing of them is a trenchless matter with restoration scrutiny attached. We map these approaches before a bore profile is drawn.

Approvals across a split jurisdiction

A corridor here can involve the municipal corporation, the urban development authority on the periphery, the state public works department, and the metro authority along its alignments. Which body owns which metre is established before any application is drafted.

The growth belt toward SG Highway and Gandhinagar is where jurisdiction most often catches clients out, because administrative boundaries there do not follow the built form.

What the Ahmedabad deliverable carries

Layered CAD with depth annotation, GIS files where a spatial record is maintained, a PDF issue set, and a report stating coverage and limitations by section — with the old city and the estates reported separately, since confidence achieved in one is not confidence achieved in the other.

On industrial plots the report additionally identifies suspected process and effluent lines as a distinct category, so the client's safety case can treat them accordingly.

Sectors that call us in here

Textile and chemical manufacturing dominate the enquiry mix, followed by city gas distribution work where a licensee needs a route proved before a tie-in near occupied frontage. Power utilities ask for feeder confirmation before cable-laying gangs mobilise on the estates.

Construction is the growing side. Plot surveys before piling on the western growth belt catch old field drains, abandoned borewells and irrigation infrastructure that predate the development, none of which appears on a layout drawing.

Telecom and enterprise routing remains steady, particularly diverse-path verification along the SG Highway corridor where several operators share the same constrained approach.

Timing and access windows

The old city and the estates run on entirely different clocks. Pol lanes are workable in the early morning before frontages open, while industrial estates prefer scheduled shutdown windows where plant operation would otherwise restrict access.

We build both into the programme at quotation stage rather than discovering them on mobilisation, because a crew waiting for access is a cost that lands on somebody either way.