Naugatuck Valley Planning Region, Connecticut Map with Towns and Land Area

How to use this map

The map opens on the Divisions view with all 19 of Naugatuck Valley Planning Region’s municipalities drawn straight from Census boundary files. Click any one to pin it and read its figures: land area in square kilometres, 2020 population and the density that falls out of those two. The tabs above the map change what the shading means. Divisions gives each unit its own colour so you can tell neighbours apart at a glance. Land area shades by size. Satellite drops one metre aerial imagery under the boundaries. Blank outline strips the fill away for printing or tracing.

The figure people misread is land area. Census land area excludes water, so a municipality with a lake or a river frontage looks smaller in the table than it does on the map. Shelton is the clearest case here: its boundary encloses 82.51 square kilometres but only 79.33 of that is land, leaving 3.18 as water. If you are measuring something that sits on the ground, use the land figure. If you are measuring something that follows the boundary, use the polygon.

What this planning region is made of

Naugatuck Valley Planning Region holds 19 towns. Southbury is the largest by land area at 101.02 square kilometres and Derby the smallest at 13.09, which makes the largest roughly 7.7 times the size of the smallest. The median sits at 52.8 square kilometres, so the spread is wide but most units cluster nearer the middle than the extremes.

Waterbury is the largest by population at 114,403, about 25 per cent of the planning region total. Waterbury is the densest at 1,546.8 people per square kilometre and Bethlehem the emptiest at 67.5, a ratio of about 23 to one. Bethlehem has 3,385 people.

Across the whole planning region the density is 421.3 people per square kilometre. That is the number to hold on to, because it explains the shape of the map: a few dense nodes and a long tail of thinly settled ground, with the average describing almost none of the individual units.

Where the data comes from

Boundaries come from the Census Bureau TIGERweb planning region subdivision layer, which is the authoritative source for municipal geography in Connecticut. Land area is the Census land measurement, which excludes inland water. Population is the 2020 Decennial Census count for each municipality.

The sources are joined on municipality name, and that join is worth checking rather than trusting. The 19 land areas sum to 1,069.1 square kilometres against a published planning region land area of 1,069.11, which agrees to the hundredth. The 19 populations sum to 450,376, which is the published planning region total to the person.

Aerial imagery, and how it is fitted to the map

The Satellite tab pulls one metre aerial imagery from the USGS National Map. One metre means each pixel covers roughly a square metre of ground, so at full zoom you can pick out individual buildings, field boundaries and the line of a farm track. That resolution matters at this scale. The national and state maps on this site use a NASA composite at five hundred metres per pixel, which is fine for showing where Connecticut sits in the country and useless for showing where a municipal line runs.

The boundaries are drawn in an Albers equal area projection fitted to this planning region, with standard parallels set inside its own latitude range. Equal area matters here because the map is shaded by area: if the projection distorted area, the shading would be lying. The imagery arrives in Web Mercator and is reprojected to match.

A check you can repeat on paper

Take Waterbury. Its land area is 73.96 square kilometres and its 2020 population is 114,403. Divide 114,403 by 73.96 and you get 1546.82 people per square kilometre, which is what the panel shows rounded to 1,546.8.

Now check it against the planning region. Waterbury holds 25.4 per cent of the 450,376 people on 6.9 per cent of the 1,069.1 square kilometres. That gap between population share and land share is the whole story of the map in one comparison.

Mistakes that catch people out

Reading polygon area as land area. The map draws boundaries, and boundaries include water. This planning region encloses 1,090.31 square kilometres of polygon against 1,069.1 of land, so 21.21 is water, about 1.9 per cent.

Assuming a city is bigger than a town. In Connecticut those words describe charter type, not size. Derby town is the smallest unit here at 13.09 square kilometres.

Expecting the average to describe a unit. At 421.3 per square kilometre the planning region average sits between Bethlehem at 67.5 and Waterbury at 1,546.8, and matches neither.

Assuming municipal lines follow roads or rivers. Many were surveyed as charter grants or survey townships long before the roads existed. The straight lines on this map are the original survey, not modern infrastructure.

Related Calculators and Reference

• Connecticut County Map, for all 9 counties and where Naugatuck Valley sits among them
• United States Map, for the national view and how Connecticut compares
• Massachusetts County Map, for the same treatment applied to another New England state
• US Census Bureau Geography, the source for boundaries, land area and population