What's Beneath the Road? The Engineering Behind Lexington's Sewer Infrastructure

Most drivers traveling down Tates Creek Road probably do not spend much time thinking about what is underneath them.

Civil engineers do.

Beginning September 21, portions of the inbound lane of Tates Creek Road between New Circle Road and Dove Run Road are scheduled to close as work continues on Lexington's Merrick trunk sewer project.

According to the Lexington-Fayette Urban County Government, the overall project will replace approximately 7,200 feet of sanitary sewer pipe along Tates Creek Road and is expected to continue through the end of 2027. The work is part of Lexington's ongoing effort to improve its sanitary sewer system under federal consent decree requirements.

For the public, the most visible part of a project like this may be orange barrels, excavation equipment, lane closures, and construction crews.

But long before the pavement is opened, a substantial amount of surveying and engineering work has already happened.

It Starts With Understanding Existing Conditions

Before engineers can design replacement infrastructure, they need to understand what is already there.

That can include:

• Existing roadway elevations

• Curbs and sidewalks

• Sanitary and storm sewer structures

• Water lines

• Utility facilities

• Property boundaries

• Rights-of-way and easements

• Buildings and other improvements

• Drainage patterns

• Existing grades and topography

A detailed existing-conditions survey helps create the base information engineers use to evaluate the site and develop a design.

And on a developed corridor, underground infrastructure can become complicated quickly.

A single roadway may contain sanitary sewer, storm drainage, water, gas, electrical, telecommunications, and other utilities—each competing for limited underground space.

Sewer Design Depends on Elevation

Sanitary sewers often rely primarily on gravity.

That means elevation matters tremendously.

Engineers must evaluate pipe slopes, depths, connection points, manhole elevations, existing utilities, roadway grades, and the surrounding terrain.

A pipe cannot simply travel from Point A to Point B on a map. It has to function three-dimensionally beneath the ground while maintaining appropriate cover, avoiding conflicts, and providing the necessary hydraulic performance.

Small elevation differences can matter over long distances.

Surveying provides the vertical information needed to understand existing conditions, while civil engineering uses that information to develop a system that works.

Then the Design Has to Reach the Ground

Once construction begins, surveyors may return to the project to provide construction staking and layout.

Plans created digitally must ultimately be translated into physical positions in the field.

Crews need to know where improvements are located, what elevations are required, where structures belong, and how the designed infrastructure relates to the existing roadway and surrounding property.

After construction, record or as-built information can also document what was actually installed.

In that sense, surveying is involved throughout much of the infrastructure lifecycle:

Measure what exists. Design what is needed. Build it in the right place. Document what was constructed.

Infrastructure We Rarely Notice—Until It Does Not Work

Sanitary sewer infrastructure is one of those public systems most people rarely think about when it is functioning properly.

But maintaining and replacing aging infrastructure is critical to protecting public health, supporting development, protecting waterways, and allowing communities to continue growing.

Lexington's Merrick trunk sewer project is one visible example of the kind of infrastructure investment taking place beneath streets throughout communities across the country.

And while the finished product may eventually disappear beneath new pavement, the work required to make it happen combines surveying, engineering, planning, coordination, construction, and long-term infrastructure management.

At Abbie Jones Consulting, PSC, our surveying and civil engineering teams help clients understand existing conditions and turn that information into practical solutions for infrastructure and development projects.

Sometimes the most important part of a project is the part you'll never see.

Abbie Jones Consulting, PSC

Surveying • Engineering • Solutions

Source

Lexington-Fayette Urban County Government. “Sanitary Sewer Construction Coming to Tates Creek Road.” September 16, 2026.