Chittenden CountyVermont
South Burlington, Vermont
Bedrock sits a median 54 ft down across 94 logs, deeper than the Vermont median of 20 ft. None of its 18 inventoried bridges is rated poor.
- Live · as of Sep 11, 2026
- 9 public sources · method
- ← All towns
Median depth to bedrock
54 ft
middle half 13–99 ft · 94 logs
Bridges rated poor
0
of 18 inventoried
Mapped landslides
45
USGS inventory points
FEMA repair $, Chittenden County
$51.8M
federal share since 2010 · county-wide
01 · Ground
Deep ground: 51% of logs go past 50 ft before rock
From 94 depth-to-rock records inside South Burlington (Vermont DEC well records). Logs cluster where people drill wells and bore for roads, so treat this as the town’s pattern, not a site answer.
Half of South Burlington's logs reach rock between 13 and 99 ft
Depth to bedrock: 10th–90th percentile whisker, middle-half box, median tick; dashed line = Vermont median.
median 54 ftVT 20 ft
050100 ft
n = 94 logsSource: Vermont DEC well records
▸ Show the numbers▾ Hide the numbers
| Depth to rock (ft) | Logs |
|---|---|
| 0–5 | 8 |
| 5–10 | 13 |
| 10–20 | 7 |
| 20–50 | 17 |
| 50–100 | 25 |
| 100+ | 24 |
Rock within 10 ft
23%
of logs (34% across Vermont). Shallow rock means ledge in excavations, refusal for driven piles and rock anchors rather than soil nails; deep ground means taller shoring and more groundwater. 51% of logs here go past 50 ft.
Mapped landslides
45
22 mass failure · 13 landslide · 4 gully head · 3 earth landslide · 2 gully. Inventory points from the USGS U.S. Landslide Inventory; many are prehistoric slides mapped from lidar.
02 · Bridges
None of South Burlington's 18 bridges is rated poor
Every highway bridge and large culvert in the 2025 National Bridge Inventory that stands inside South Burlington. Median age 64 years.
28% good, 0% poor
FHWA good / fair / poor rating — the lowest of deck, superstructure, substructure or culvert.
- Good5 · 28%
- Fair13 · 72%
- Poor0 · 0%
Structures by decade built
n = 18 structuresSource: FHWA National Bridge Inventory 2025
▸ Show the numbers▾ Hide the numbers
| Built | Structures |
|---|---|
| 1960s | 16 |
| 1990s | 1 |
| 2000s | 1 |
03 · Dams & disasters
Chittenden County has drawn $51.8M in federal disaster repair since 2010
FEMA Public Assistance is reported by county, so the figure below is Chittenden County-wide context, not a South Burlington number.
FEMA Public Assistance, Chittenden County
$51.8M
Federal share obligated across 522 projects in 16 declared disasters since 2010. The largest category is emergency protective measures (61%); roads & bridges took $13.1M.
04 · Money & permits
2 ground-related permits in the city's open data
Ground-related permits in open data
2
Permits in the city’s open-data portal that mention retaining walls, excavation or foundations. Only a handful of portals are read, so this counts what is published, not everything built.
05 · Next door
South Burlington and the 7 towns that border it
A dash means no data for that layer, not zero.
| Town | Poor bridges | Rock depth |
|---|---|---|
| South Burlington, VT | 0 / 18 | 54 ft |
| Colchester, VT | 1 / 15 | 35 ft |
| Essex, VT | 0 / 11 | 15 ft |
| Winooski, VT | 0 / 11 | 14 ft |
| Williston, VT | 0 / 10 | 23 ft |
| Shelburne, VT | 0 / 4 | 12 ft |
| Burlington, VT | 0 / 4 | 95 ft |
| Essex Junction, VT | 0 / 3 | 90 ft |
Where these numbers come from
Method, sources & caveats
South Burlington is the Census county subdivision 5000766175 (Chittenden County). Every record is placed here by its coordinates, not by the place name the source uses.
- Towns are Census county subdivisions: cities, towns, plantations, and Maine/New Hampshire unorganized territories and townships. Every record is placed in a town by its coordinates (point-in-polygon), not by the source's own place label — so a bridge in Roxbury counts for Boston and a well in 'North Waltham' counts for Waltham.
- Bridges: FHWA NBI 2025, highway structures ≥ 20 ft including large culverts. 'Poor' is FHWA's good/fair/poor rating (lowest of deck, superstructure, substructure or culvert ≤ 4). Percent-poor is shown only for towns with at least 5 structures.
- Depth to bedrock is the median of driller- and boring-reported depths in the town, shown only where at least 10 logs exist. Water-well logs over-sample rural lots and hilltops; one town median never describes a particular site.
- Bedrock depths use the same state databases and filters as the Bedrock & soils module (bedrock wells and borings that reached rock, 0 < depth ≤ 400 ft, exact re-filings dropped), but every log is placed in a town by its coordinates rather than the driller's town field, so town counts can differ slightly between the two pages. Connecticut and Rhode Island have no statewide public well-log database with depths.
- Dams: only high-hazard-potential dams whose latest condition assessment is Poor or Unsatisfactory are counted (live NID). Connecticut and Rhode Island assessments may lag.
- FEMA Public Assistance dollars are federal share obligated for disasters declared since 2010, reported by county — they are county context, not a town figure.
- Grant awards are Massachusetts only (EEA Dam & Seawall program, MVP Action grants, CZM Coastal Resilience). Other states' programs are not yet included.
- Ground-related permit counts cover only the municipal portals the pipeline reads (Boston, Cambridge, Somerville, Worcester, Framingham, Providence, Portsmouth, Hartford and a few others) — an absent count means 'not covered', not zero.
- Data as of
- Sep 11, 2026
- Generated
- Sep 11, 2026
- Records
- 367,748
- Refresh
- Live pull · weekly
- U.S. Census Bureau cartographic boundary files — county subdivisions (2024, 1:500k)Public domain
- FHWA National Bridge Inventory (2025 delimited files)Public domain
- USACE National Inventory of DamsPublic domainHigh-hazard dams rated Poor or Unsatisfactory (live NID).
- USGS U.S. Landslide InventoryPublic domain
- MassGIS / Massachusetts Geological Survey — Bedrock Data PointsPublic recordBorings and well logs that reached rock (MassDEP well drillers, USGS, MWRA, MassDOT…); seismic/HVSR and map-derived shallow-bedrock/outcrop points excluded.
- NH DES Water Well Inventory, Maine Geological Survey Wells Database, Vermont DEC well recordsPublic recordBedrock wells only; driller-reported depth to bedrock / overburden thickness.
- OpenFEMA Public Assistance Funded Projects Details (v2)Public domain
- MA EEA / CZM grant awards — Dam & Seawall, MVP Action, CZM Coastal ResiliencePublic record
- Municipal open-data permit portals (Boston, Cambridge, Somerville, Providence, Portsmouth, others)Public recordOnly permits flagged as ground-related (retaining walls, excavation, foundations) are counted.
Published by Earth Support Corp as a public resource. Regional statistics for planning and curiosity. They are not an engineering report, a bid recommendation or a statement about any particular site, firm or project. Spot an error? Tell us and we will correct it. Full method: methodology.