Earth Support Corp

Hillsborough CountyNew Hampshire

Brookline, New Hampshire

1 high-hazard dam is rated in poor or unsatisfactory condition. Bedrock sits a median 15 ft down across 1,230 logs, shallower than the New Hampshire median of 20 ft.

Median depth to bedrock

15 ft

middle half 8–32 ft · 1,230 logs

Bridges rated poor

1

of 8 inventoried

Poor high-hazard dams

1

National Inventory of Dams

FEMA repair $, Hillsborough County

$39.7M

federal share since 2010 · county-wide

01 · Dams & disasters

1 high-hazard dam needs work

FEMA Public Assistance is reported by county, so the figure below is Hillsborough County-wide context, not a Brookline number.
High-hazard dams in poor condition in Brookline
DamConditionBuilt
Pierce Pond DamSquam RiverPoor1924

High hazard potential means failure would probably cost lives — it rates the consequences, not the dam’s condition.

FEMA Public Assistance, Hillsborough County

$39.7M

Federal share obligated across 415 projects in 10 declared disasters since 2010. The largest category is emergency protective measures (90%); roads & bridges took $1.8M.
Dams, disasters & moving ground

02 · Ground

Rock turns up a median 15 ft down

From 1,230 depth-to-rock records inside Brookline (NH DES well inventory). Logs cluster where people drill wells and bore for roads, so treat this as the town’s pattern, not a site answer.

Half of Brookline's logs reach rock between 8 and 32 ft

Depth to bedrock: 10th–90th percentile whisker, middle-half box, median tick; dashed line = New Hampshire median.
median 15 ft
NH 20 ft
02040 ft
01002003004000–5 ft5–10 ft10–20 ft20–50 ft50–100 ft100+ ft
n = 1,230 logsSource: NH DES well inventory
▸ Show the numbers
Depth to rock (ft)Logs
0–5143
5–10273
10–20320
20–50333
50–100149
100+12

Rock within 10 ft

40%

of logs (31% across New Hampshire). 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. 12% of logs here go past 50 ft.
Bedrock & soils across New England

03 · Bridges

1 of 8 bridges are rated poor — above the New Hampshire rate of 8%

Every highway bridge and large culvert in the 2025 National Bridge Inventory that stands inside Brookline. Median age 83 years.

38% good, 13% poor

FHWA good / fair / poor rating — the lowest of deck, superstructure, substructure or culvert.
  • Good3 · 38%
  • Fair4 · 50%
  • Poor1 · 13%
n = 8 structuresSource: FHWA National Bridge Inventory 2025
▸ Show the numbers
BuiltStructures
1930s3
1940s3
1980s2

The poor-rated bridges

Bridges rated poor in Brookline
CarriesOverBuiltDaily traffic
DUPAW GOULD ROADLANCY BROOK1987559
Every poor bridge in New England

04 · Next door

Brookline and the 5 towns that border it

A dash means no data for that layer, not zero.
Brookline compared with neighbouring towns
TownPoor bridgesRock depth
Brookline, NH1 / 815 ft
Townsend, MA1 / 1621 ft
Milford, NH1 / 1315 ft
Pepperell, MA1 / 716 ft
Hollis, NH0 / 218 ft
Mason, NH—11 ft

Where these numbers come from

Method, sources & caveats

Brookline is the Census county subdivision 3301108100 (Hillsborough 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

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.

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