Topographic survey for water and sewer lines

Water supply and sewer design differs from other utility work in one critical respect: a gravity sewer only works at the correct gradient. An elevation error of a few centimetres can lead to standing wastewater, blockages and having to relay the pipe. That is why this type of survey pays particular attention to vertical accuracy.

During the survey we open existing water and sewer manholes and measure cover and invert levels, as well as the direction, diameter, material and depth of incoming and outgoing pipes. Along the route from the connection point to the site we record relief, pavements, other utilities, fences and structures. Pumping stations, hydrants, valve chambers and drainage elements are shown separately.

Elevations are carried with a digital level at ±0.3–1.5 mm/km accuracy, while plan positions are measured with GNSS RTK and total stations. The result is a 1:500 topographic plan plus a longitudinal profile from which the designer can calculate gradients. Typical uses are connecting a house to the mains, external networks for residential complexes, sewer collectors and treatment plant design.

The plan follows the technical conditions of the water utility and the applicable codes (AzDTN/SNiP).

When you need it

• Connecting a private house to water and sewer mains
• External water and sewer networks for residential complexes
• Design of a sewer collector or pumping station
• Siting a local treatment plant
• Rehabilitation or relocation of old lines

What's included

• 1:500 topographic survey along the route
• Manholes opened, cover and invert levels measured
• Pipe diameters, materials and directions recorded
• Precise levelling with a digital level
• Other utilities and crossings located
• Longitudinal profile along the route

How we work

1. Reviewing technical conditions and connection points
2. Setting benchmarks and running a levelling line
3. Opening and measuring manholes
4. Topographic survey along the route
5. Drafting the plan and profile, then handover

Deliverables

• Route topographic plan at 1:500 (DWG, PDF)
• Longitudinal profile
• Manhole schedule (cover and invert levels, diameters)
• Technical report