A Gazetteer for the United States and Canada
Census Data for Norwalk ...
The most recent Census Estimate<1> was for 2018 and it gave Norwalk a population of 11,517 people.
The last Decennial Census<2> was in 2010, which gave Norwalk a population of 8,945 people.
The city of Norwalk is located in Warren County. The 2010 Census gave Warren County a population of 46,225 people. This means that Norwalk had 19.35% of the county's total population, making it Warren's 2nd most populous community.
When the Census Bureau conducts a census for a city like Norwalk, they draw a boundary around the area in which they are going to conduct their count - this defines the sampling area (usually shaped as a polygon). The shape of the sampling area can be quite complex and it's important to keep in mind that the boundaries of the sampling area may or may not match the recognized boundaries of the city.
Things like the population, area and housing for Norwalk reflect the sampling area. Since the shape of the sampling area and the actual boundaries of Norwalk might be different, it's best to check with the U.S. Census Bureau to resolve any difference between the two.
The 2010 Census shows that the sampling area for Norwalk has a total area of 11.1 square miles [28.7 km²]. Of this total, 10.74 square miles [27.8 km²] is land, with the balance (3.19%) being water (0.35 square miles [0.9 km²]).
Warren County has a land area of 569 square miles [1,475.8 km²]. At 10.74 square miles [27.8 km²], Norwalk has 1.89% of the county's total land area.
Not only does the sampling area define boundaries, it also has a GPS location (latitude & longitude) that indicates a point within the sampling area (usually the center of the polygon, known as the centroid). At the time of the 2010 Census, the sampling area was located at:
Lat: 41° 29' 30" (or 41.49°) [Map]
More information on this topic and the changes between the 2000 Census and the 2010 Census can be found in the section for our Census-to-Census Observations ... (see below).
Population Density ...
Using the population (8,945 people) and land area (10.74 square miles [27.8 km²]) values from the 2010 Census, Norwalk had a population density of 806 people per square mile [311.2 people/km²].
In comparison, the 2000 Census shows Norwalk had a population of 6,884 people and a land area of 6.56 square miles [17 km²]. This gives a population density of 1,015 people per square mile [392.2 people/km²]
NOTE: Be aware that when comparing population density between the 2000 Census and the 2010 Census, there were changes in the sampling area for Norwalk. You need to be careful when making such a comparison, the differences are likely to lead to an apple-to-oranges comparison. More information about these differences can be found in the section Census-to-Census Observations ... (see below).
Housing Units ...
At the time of the 2010 Census, Norwalk had 3,450 Housing Units<3> and with its population of 8,945 people, this averages 2.59 people per Housing Unit.
The 2010 Census shows Norwalk had a land area of 10.74 square miles [27.8 km²]. This translates to 310.9 Housing Units per square mile [120 housing units/km²].
From the Census of 2000: Norwalk had 2,382 Housing Units, a population of 6,884 people and a land area of 6.56 square miles [17 km²]. This gives a density of 2.89 people per Housing Unit and 351.5 Housing Units per square mile [135.7 housing units/km²].
NOTE: Repeating the caution above (under Population Density), be aware that when comparing Housing Units between the 2000 Census and the 2010 Census, there were changes in the sampling area for Norwalk and you need to be careful when comparing values between the censuses. More information about these differences can be found in the section called Census-to-Census Observations ... (see below).
Warren County ...
The community of Norwalk is located in Warren County.
The county had a population of 46,225 people at the 2010 Census. With it's population of 8,945 people, Norwalk represented 19.35% of the county's total.
In addition, where the city of Norwalk has a population density of 806 people per square mile [311.2 people/km²], Warren County averages 81.1 people per square mile [31.32 people/km²].
For more information, please visit our Census Page for Warren County.
Population Rings for Norwalk ...
To help identify the number of people who live in Norwalk and the surrounding area, we have drawn concentric rings centered on Norwalk. We counted the number of communities within each ring and summed their populations.<4>
Census-to-Census Observations ...
When the Census Bureau takes a census count (or enumeration) for Norwalk, they start by specifying the boundaries of the area to be counted. This area (or sampling area) is a polygon and its shape can be quite complex - it may or may not match the geographical boundaries of Norwalk. It's important to note that from one Census to the next, the shape and location of the polygon can change. If you need precision or details about the methodology of the Census, you should visit the U.S. Census Bureau for a definitive answer.
The sampling area (or polygon) given for the 2010 Census is 63.75% larger than the 2000 Census.
The 2010 Census shows that the total area for Norwalk was 11.1 square miles [28.7 km²]. Of this total, 10.74 square miles [27.8 km²] is land, with the balance (3.19%) being water (0.35 square miles [0.9 km²]).
The 2000 Census shows a total area of 6.78 square miles [17.6 km²]. Of this total, 6.56 square miles [17 km²] is land, with the balance (1.94%) being water (0.22 square miles [0.6 km²]).
While generally coinciding with the GPS location (latitude/longitude) of Norwalk, the latitude and longitude given by the Census Bureau actually indicates the GPS location of the polygon for Norwalk.
For the 2010 Census, the location was given as:
Lat: 41.491679° (or 41°29'30" N) [Map]
For the 2000 Census, the location given was:
Lat: 41.483403° (or 41°29'0" N) [Map]
The difference indicates that the U.S. Census Bureau moved the location of the polygon for the 2010 Census 7,117 feet to the northwest<5> of the location that was used in the 2000 Census.
The U.S. Geological Survey (USGS) and the U.S. Board on Geographic Names (BGN) have assigned a unique GNIS identifier (#2395273) to Norwalk. This identifier also marks a GSP point on the map, and that point lies within the boundaries of Norwalk. The GNIS point has been mapped to the latitude/longitude:
Lat: 41.489465° (or 41°29'22" N) [Map]
The GSP location given for the 2010 Census lies 5,185 feet to the west<6> of the point given by the GNIS for Norwalk. For more information about this and the relationship of the various Federal Codes, please visit our Misc Page for Norwalk.
Miscellaneous Information for Norwalk ...
The Federal government has assigned various identifying codes to each community, county and state. At one time or another, the US Census Bureau has used one (or more) of the following identifiers when referring to either Warren County or the city of Norwalk:
The GNIS Codes ...
The current system of identification is called the Geographic Names Information System (GNIS). The following GNIS codes relate to Norwalk:
GNIS ID for Norwalk: 2395273
The FIPS Codes ...
An earlier (and largely obsolete) identification method was called the Federal Information Processing Standard (FIPS):
State Code: 19 (Iowa)
County Code: 181 (Warren County)
Place Code: 57675 (Norwalk)
Misc. Census Codes ...
Norwalk is located in Census Region #2 (the Midwest Region) and Division #4 (the West North-Central Division).
The US Postal Service ZIP Code ...
While some people have used a ZIP code to identify a community, the purpose of the ZIP code was to make mail delivery more efficient by grouping addresses together. Although the ZIP Code doesn't specifically identify a city like Norwalk, it does identify addresses that are in (or near) Norwalk. It's important to remember that the boundaries of a ZIP Code can be changed, re-assigned or overlapped with other ZIP Codes.
The ZIP code for Norwalk: 50211<7>
Census ZCTA Codes ...
The US Census Bureau created statistical entities that they call ZIP Code Tabulation Areas (ZCTAs) and these ZCTAs are frequently confused with the ZIP codes that come from the US Postal Service (USPS).
ZCTAs were first created for the 2000 Census and at that time, they were based upon the USPS ZIP codes. While largely covering the same areas, the boundaries of a ZCTA do not necessarily match the boundaries of a postal ZIP code with the same number. For example, while a postal ZIP code can cross a county or state line, a Census ZCTA can not. They should be treated as separate entities with no correlation between them.
For more information about the various Federal identification codes, please visit our Misc Page for Norwalk.
Other Roadside Stops ...
Off-the-Road Links ...
The official website of the U.S. Census Bureau
The official website for Norwalk: www.ci.norwalk.ia.us/
The official website for Warren County: www.co.warren.ia.us/
The official website for State of Iowa: https://www.iowa.gov/
The official website of the U.S. Board on Geographic Names (BGN)
The official website of the U.S. Geological Survey (USGS)
Please keep in mind that we can not guarantee the accuracy or timeliness of the information on this website, so use with care. We encourage you to double-check the information that is critical to you.
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This page was last modified: 27 Aug 2019