Falmouth, Massachusetts: what the ground under the city is like
Falmouth sits in Barnstable County, on atlantic coastal plain. The soil mapped here is predominantly classified well drained — and that classification, not the rainfall total, is what decides how a basement behaves.
33% of the mapped soil area around Falmouth is wet enough that the USDA describes it as needing artificial drainage.
Linear extensibility 2.5% — low.
Shallowest annual water table around 105 cm (3.4 ft).
Values are for Barnstable County, which is what the soil survey resolves to. Full county report · soil map for a specific address.
The ground under Falmouth
Atlantic coastal plain. Unconsolidated sands and clays at low elevation
Extremely variable over short distances: sand and saturated clay side by side. A county figure means less here than anywhere else we cover — the individual parcel decides.
When it shows up here
| Water | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ground movement | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
Water peaks in April and May with the spring rains. The dry late summer is when soil movement shows up instead, so the two problems take turns.
Climate pattern for this physiographic region, not a forecast for your house and not from the soil survey. It answers a question homeowners actually ask: when does this show up.
What repairs cost in Massachusetts
| Reference job | Modelled range |
|---|---|
| Interior drain along two walls + sump pump | $5,950–$12,800 |
| Exterior excavation of one 40 ft wall | $4,500–$12,750 |
| Underpinning on 10 piers | $17,700–$37,750 |
Regional factor for MA: ×1.18. Full cost breakdown for Massachusetts · run your own dimensions.
ZIP codes in Falmouth
02540, 02541
Soil does not stop at a city boundary, and neither does this data — every ZIP code above resolves to the same county soil survey. For the individual survey polygons around one address, use the soil map.
Other places in Barnstable County
Questions about Falmouth
Is the soil the same everywhere in Falmouth?
No. These values describe Barnstable County as a whole, which is the unit the soil survey publishes. Within a city, map units change over a few hundred metres — the soil map draws the actual polygons around a point and is the honest answer for one address.
Which contractor should I call in Falmouth?
We do not rank or recommend individual firms and we are not one. What this page is for is knowing which kind of work the ground here points to before anyone quotes you, and which claim to check. If you want quotes, the form below passes your request to the named networks.
Does this replace an inspection?
No. It tells you what the ground is; an inspection tells you what your building is doing on it. The useful order is: read this, print the brief for your county, then have someone look.
Get quotes in Falmouth
We pass what you enter to the contractor networks listed below. You choose whether to hire anyone.
Page data updated