This is a buildable mountain lot, but expect to spend money on the slope. Average grade is 22%, soils are a Group C residual loam over weathered rock, and you're outside any FEMA flood zone. The biggest cost drivers will be retaining walls or a cantilevered foundation, perched groundwater above the rock interface, and stormwater runoff control on the downhill side. No wetlands flagged; nearest stream is 380 ft away. A geotech and a residential structural engineer should be on your team before you commit.
| Layer | Finding | What it means |
|---|---|---|
| FEMA flood zone | Zone X (unshaded) | Outside the 500-yr floodplain. Flood insurance not federally required. |
| Wetlands (NWI) | None on parcel | No NWI-mapped wetlands within 200 ft. |
| Soil (SSURGO) | Evard-Cowee complex, 15–30% slopes | Hydrologic group C/B. Drainage class: well drained. Moderate erosion potential. |
| Slope | 22% average | Sampled across the parcel from USGS 3DEP. Triggers most NC steep-slope ordinances. |
| Elevation | 2,310 ft | Mid-slope terrain typical of Town Mountain area. |
| Streams (NHD) | Nearest 380 ft (intermittent) | Outside typical NC riparian buffer (50 ft). Confirm at survey. |
| Land cover | Deciduous forest (NLCD 41) | ~3% impervious. Substantial tree clearing likely required for building envelope. |
| Design rainfall | 100-yr / 24-hr: 6.8 in | High-intensity events common in WNC. Driveway and roof drainage need real capacity. |
Implications: NC building code triggers stricter foundation, drainage, and grading review above 25% slope, and many local mountain-county ordinances tighten further at 20%. Expect engineered footings (pier/grade-beam or stem-wall), site-cast or modular retaining walls, and a stormwater plan even for a single-family home. Driveway grade will need careful design — 12% maximum is the practical limit for winter passability.
Implications: Common WNC residual mountain soil. Reasonable infiltration, but expect perched water above the rock interface in wet seasons — design foundation drains accordingly. Septic suitability is marginal at this slope; verify with Buncombe Co. Environmental Health if no public sewer is available.
| Duration | 2-yr | 10-yr | 25-yr | 100-yr |
|---|---|---|---|---|
| 15-min | 0.71" | 1.09" | 1.32" | 1.66" |
| 1-hr | 1.27" | 1.99" | 2.43" | 3.09" |
| 24-hr | 2.84" | 4.41" | 5.39" | 6.83" |
Implications: Roof gutters and downspouts should handle the 10-yr / 5-min intensity (~5.5 in/hr). The 100-yr / 24-hr depth of 6.83" is what stormwater BMPs must store and release. WNC sees Helene-class events that exceed Atlas 14 routinely — for high-value structures, consider designing one storm size larger than code minimum.