Gross acres are not usable acres
We measure what the maps take off the top, and whether the land that remains is still in one piece.
What we read
Federal flood-hazard maps, federal wetland maps, mapped streams, elevation models and contours, the federal soil survey, and state geology.
What the record establishes
- Where mapped floodway and floodplain cross the tract, and how much.
- Mapped wetland acreage on the tract.
- How much land remains after those are removed, and whether it stays connected.
- Relief and slope across the site.
- Soil concerns at survey level: poor drainage, wet soils, shrink-swell clays, shallow rock, a seasonal high water table.
What it cannot establish
Wetlands as a scientist would flag them on the ground. Which streams are regulated. Bearing capacity. Depth to rock at the building pad. Groundwater at the foundation. Final grading quantities or a stormwater design. A figure for acreage that an authority has approved for building.
Shape matters as much as area
A tract can pass on total dry acres and still fail, because a stream splits the dry land into pieces too small to use, or a road separates two parcels. We look at whether the remaining ground holds a workable footprint, not only at the sum.
Floodway and floodplain are different
The floodway is the channel that must stay open. The wider floodplain can sometimes be built on with engineering and approvals. We report them separately. Treating them as one either throws away good land or counts on land you cannot use.
Where public data misleads
- An error that reads as zero. When a map service fails, a careless process records “no wetlands.” A failed lookup is an unknown, never a clean result.
- Counting the same ground twice. Floodway sits inside floodplain, and wetlands often sit inside both. Adding the three overstates the loss. They must be merged, not summed.
- Counting what is not on the parcel. A nearby feature is not a deduction unless it crosses the boundary.
- Old geology. The state geologic map is coarse and dated. It cannot tell you rock depth on a given parcel.
Who confirms it
A surveyor, a civil engineer, a wetland scientist, the local floodplain administrator, and a geotechnical engineer, depending on the question.
What we hand you
Gross acreage, each mapped constraint measured on the tract, the connected remainder, the soil and slope concerns, and which fieldwork to order first. Our usable acreage calculator shows the arithmetic.
Questions
No wetlands are mapped on my land. Is it clear?
The maps did not show any. Federal wetland maps are drawn from aerial imagery and miss features on the ground. A delineation answers the question.
Tell us what the project needs
Load, acreage, counties, and timeline. We reply with how we would run the search and where we would start.