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Northwest Hills Planning Region, Connecticut

A shallow water table limits basements on 40% of Northwest Hills Planning Region's mapped land, a higher share than 58% of US counties and the 3rd highest of 9 Connecticut counties. Shrink-swell clay limits houses without basements on 0%.

None of the county is in drought on the October 13, 2026 Drought Monitor map. 66% of homes were built before 1980, against 50% nationally; the median home dates from 1967.

Data as of October 13, 2026 · sources

0%

expansive clay: shrink-swell limits slab homes

40%

high water table: limits basements

0%

in drought, October 13, 2026

66%

of homes built before 1980

Soil under Northwest Hills Planning Region

Expansive clay (limits slab homes)0.0%
High water table (limits basements)39.6%
Septic fields very limited82.5%
Clay swell (LEP, by area)0.9%
High-swell land (LEP 6%+)under 0.1%
Mapped soil516,985 acres
Soil seriesShare hereSeries nationally: high water table
Charlton12%n/a
Canton8%n/a
Chatfield7%n/a
Paxton7%n/a
Woodbridge5%n/a
Hollis4%n/a
Naugatuck Valley Planning Region: 37%Dutchess County: 20%Capitol Planning Region: 40%Columbia County: 28%Berkshire County: 33%Hampden County: 33%Putnam County: 32%Western Connecticut Planning Region: 35%Northwest Hills Planning Region Naugatuck ValleyDutchessCapitolColumbiaBerkshireHampdenPutnamWestern ConnecticutNorthwest Hills
Northwest Hills Planning Region (heavy outline) and nearby counties, shaded by high water table share.under 10%10-25%25-40%40-60%60%+

How we count

What the numbers mean here

On 40% of Northwest Hills Planning Region's mapped land, soil stays saturated within about 6 feet of the surface for part of the year, which is basement depth.

USDA rates 82% of the land very limited for septic absorption fields.

Drought

0% of the county is in drought (D1 or worse) on the October 13, 2026 map. Part of the county was in drought in 12 of the last 52 weeks; the most was 100% of its area, in 3 weeks, most recently on the June 30, 2026 map.

October 21, 2025Share of area in drought, weeklyOctober 13, 2026
Category, October 13, 2026Share of county
D0 abnormally dry or worse53.1%
D1 moderate drought or worse0%
D2 severe or worse0%
D3 extreme or worse0%
D4 exceptional0%

Flood and rain records

FEMA's flood data and NOAA's county rainfall series still report Connecticut by its 8 former counties, which don't line up with the 9 planning regions that replaced them in 2022. This page leaves those numbers out rather than guess at a split.

Homes

Housing units55,752
Median year built1967
Built before 198066%
Built 2000 or later12%
Owner-occupied76%
Median value, owner-occupied$335,600
Single-family detached75%

What repairs cost

Published ranges from cost guides, not quotes. More sources, and where they disagree.

WorkRangeSource
Basement waterproofing, US $3,000 to $10,000 Fixr, February 6, 2026
Sump pump installation, US $800 to $2,000 Fixr, January 31, 2025
Crawl space encapsulation, US $2,000 to $8,000 Fixr, August 29, 2025

Nearby counties

PlaceDistanceExpansive clayHigh water table
Naugatuck Valley Planning Region, CT 24 mi under 1% 37%
Dutchess County, NY 28 mi under 1% 20%
Capitol Planning Region, CT 33 mi under 1% 40%
Columbia County, NY 34 mi 1% 28%
Berkshire County, MA 36 mi 0% 33%
Hampden County, MA 36 mi 0% 33%
Putnam County, NY 40 mi 0% 32%
Western Connecticut Planning Region, CT 41 mi 0% 35%

Sources: USDA SSURGO (August 5, 2026) · US Drought Monitor (October 13, 2026) · Census ACS 2020-2024. Methods · Data status