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Before the Dozer: Building a Visual Baseline for a Development Site

Writer: Jonathan G. Browning
Jonathan G. Browning
Oct 7
4 min read

The day the first dozer rolls onto a site, the original ground starts to disappear. Trees come down. Low spots get filled. Drainage paths move. Weeks later, nobody remembers exactly what the property looked like before.

A visual baseline fixes that. It is a dated record of the site as it stood before work began. It is a small effort compared to the project, and it answers questions that come up later, often when people disagree.


Why a baseline matters

A pre-construction record helps with things that are hard to reconstruct:

  • Drainage. Where water ran before grading, and whether neighbors' runoff patterns changed.

  • Boundaries and access. Fence lines, existing roads, culverts, and gates.

  • Existing conditions. Old foundations, wells, dumps, or structures that need to be dealt with.

  • Vegetation. Tree lines and buffers that may need to stay.

  • Neighbors. The condition of adjacent roads, fences, and structures before heavy equipment arrives.

It also sets up everything after it. Progress photos mean more when there is a clean "before" to compare against.


Know what permits are coming

In Tennessee, stormwater from construction sites is regulated by TDEC. The TDEC NPDES Stormwater Construction Permit page says the permit applies to construction sites involving clearing, grading, or excavation that result in an area of disturbance of one or more acres, and to activities disturbing less than one acre if they are part of a larger common plan of development or sale.

Getting coverage involves preparing a Stormwater Pollution Prevention Plan, or SWPPP, and submitting a Notice of Intent with a site map and fee through TDEC's online system, MyTDEC Forms.

A good baseline does not replace any of that. But clear, dated imagery of existing drainage, slopes, and streams is useful context for whoever writes the plan, and it shows what the site looked like before controls went in.


Pull the public maps first

Before anyone walks the site, gather what is already published.

  1. Soils. The USDA's Web Soil Survey provides soil data from the National Cooperative Soil Survey, built for land-use and management decisions. It maps the soil types across a property, which can matter for drainage, septic, and foundations.

  2. Historical topography. The USGS TopoView collection shows topographic maps of an area through history. USGS notes it began mapping the nation's topography in 1879 and produced new versions over the years. Old maps can show former roads, structures, ponds, and stream paths.

  3. Flood zones. FEMA's Flood Map Service Center lets you search FEMA flood maps by address. Check it early.


Survey GPS receiver on a pole set up over sandy ground

What to capture on site

A baseline should be repeatable. If you cannot stand in the same spot later, it is a snapshot, not a baseline.

  • Overhead imagery. A full-site aerial view from a consistent height, plus closer passes over drainage areas and boundaries.

  • Ground photo points. Fixed, marked spots around the perimeter and at key features, each shot in the same direction every visit.

  • Drainage features. Ditches, culverts, springs, wet areas, and outlets, ideally after a rain.

  • Access and frontage. The road, entrance, and the condition of the public road surface.

  • Neighboring edges. Fences, structures, and tree lines along shared boundaries.

Label every file with the date and photo point number. Write down the weather and any recent rainfall.


Mind the rules for aerial work

Aerial imagery is the fastest way to capture a whole site. It is also regulated. Commercial flights fall under the FAA's Part 107. Airspace near airports may need authorization, and active work zones can bring people into the flight area. Plan the baseline flight before crews and equipment arrive, when the site is empty, and it is simpler for everyone. At 48 Pegasus, flights are handled by licensed FAA Part 107 remote pilots.


Turning the baseline into a Stack

At 48 Pegasus, we think of this as layering. The aerial image is one Layer. Soil, historical topography, and the flood lookup are others. Put together, they become a pre-construction Stack: a short package an owner, engineer, or contractor can open months later and understand.


Practical takeaways

  1. Capture the site before any clearing or grading.

  2. Know whether the project will need TDEC construction stormwater coverage.

  3. Pull soil, historical topographic, and flood map information first.

  4. Use fixed, repeatable photo points and a consistent aerial view.

  5. Date everything and note recent weather.

If you have a development site and want a clear baseline before work starts, contact 48 Pegasus, serving properties within 75 miles of Macon County, Tennessee, across Middle Tennessee and South Central Kentucky.


Sources

Photos: cover by Iain / Unsplash; inline by Valerie V / Unsplash. Free to use under the Unsplash License.

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