1. Choose the right method at the right time

There are a number of techniques available for drain mapping and different methodologies and survey types can be employed. These range from utility record searches at the feasibility stage, to full drain detection and verification. A good relationship with a professional surveyor, who will take the time to discuss the requirements and advise on the most suitable methodology across the duration, can add much value to a project, minimising survey time and reducing costs.

2. Guesswork & logic doesn’t always pay

In an ideal world, pipes would run from A to B, and it would be easy to tell where drains run from the surface. Unfortunately, we often find this is not the case; smaller pipes in particular can take unexpected turns.

One of OmegaGeo’s recent commissions was to identify which of three manholes outside a property was connected to the drainage system. The obvious guess was the manhole directly in front of the property.

Our experienced team had initial doubts about the logical pipe run, and their suspicions were confirmed by mapping them using electromagnetic detection.

As can be seen from the drawing, the route of the drain, shown by the brown line, took an unexpected turn, and ended at the least likely and furthest manhole. On the same survey, an underground inspection chamber was also detected on our CCTV, completely hidden at surface level – a vital piece of information for anyone needing to investigate the drains at a later date. This is now fully recorded on the topographical survey for future reference.

Employing the correct detection methodology saved unnecessary excavations and disruption to the road network, associated costs, and allowed the project to progress without adding unnecessary delay.

OmegaGeo were commissioned to provide a drain map onto their existing topographical survey and provide a CCTV condition report of all the drainage in a parking area to be developed.

The unlikely option. The manhole cover directly opposite the house, and in line with the drain, is in fact unrelated to the waste pipe.

3. Commissioning an as-built drain survey is good practise in the short and long term.

On completion of a construction project involving drainage networks, it is good practise, and an investment for the future, to commission an accurate as-built drain survey. This is particularly useful when networks run under roads and highways, and routine maintenance requires maximum speed and efficiency. A full as-built utility survey provides vital utility records, allowing future inspections and investigations to be conducted with minimum human resources using remote robotic techniques, and ultimately results in minimum disruption to transport networks, contributing to significant cost savings.

OmegaGeo offer a full spectrum of drain survey methods, providing the most efficient solution for each given stage of a project. Deliverables can be provided in 2D format and/or mapped to BIM standards. In addition, detection can be combined with CCTV to provide a full condition report.

OmegaGeo | February 2020 | Drain Mapping – 3 reasons to build a trusting relationship with a professional team