Township · Illinois
Spring Bay Township, Illinois
Spring Bay Township, township, in Woodford County, Illinois. Spring Bay Township had 2,529 residents on July 1, 2025 by the Census Bureau's estimate, up 0.2% since 2020; the 2020 Census counted 2,536 and the ACS 2020-2024 5-year estimates put it at 2,531 (±37). GEOID 1720371611.
Residents, July 2025 estimate
2,529
Census Bureau estimate (no margin published)
2020 Census count: 2,536 · ACS 2020-2024: 2,531 ±37
Median household income
$75,846
±$19,371 (90% margin)
Illinois: $83,390
Median home value
$169,100
±$35,648 (90% margin)
Illinois: $263,300
Median gross rent
$923
±$166 (90% margin)
Illinois: $1,274
Where is Spring Bay Township and what county is it in?
Spring Bay Township is a township in Woodford County, Illinois. It covers 10.1 square miles of land, 251 residents per square mile in 2020.
2 places lie inside Spring Bay Township: Spring Bay (village, 474 in 2020) and Bay View Gardens (village, 354 in 2020).
Spring Bay Township is in the Peoria, IL metropolitan statistical area, which takes in 5 counties (Census Bureau delineation, July 2023).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Spring Bay Township, and is it growing?
The Census Bureau estimates that 2,529 people lived in Spring Bay Township on July 1, 2025, up 0.2% since 2020, while Illinois shrank 0.8%. The 2020 Census counted 2,536 residents. The 2020-2024 American Community Survey, a five-year sample, puts the population at 2,531 (±37).
| Measure | Spring Bay Township | Woodford County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 2,531±37 | 38,312 | −135 |
| Households | 1,013±99 | 14,685 | no clear change |
| Average household size | 2.50±0.25 | 2.54 | no clear change |
| Housing units | 1,088±101 | 15,758 | −189 |
Spring Bay Township's population since 2000
From 2,552 in 2000 to 2,529 in 2025: down 0.9%. The 2000, 2010 and 2020 figures are census counts, each for Spring Bay Township as it was drawn that year: a place that annexed land, or a community that has since incorporated, covered a different area then. The 2005 figure is the Census Bureau's intercensal estimate, revised to fit the 2000 and 2010 counts and drawn on 2010 boundaries; 2015 and 2025 are July 1 estimates made from the census before them.
Source: The 2000, 2010 and 2020 Census counts and the Census Bureau's population estimates (intercensal 2000-2010, Vintage 2020, Vintage 2025) · Census population estimates
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Spring Bay Township?
The median resident of Spring Bay Township is 41.5 years old; 19.8% are under 18 and 18.3% are 65 or older. The largest group is non-Hispanic white residents at 91.9%, then non-Hispanic residents of two or more races at 4.9%.
| Measure | Spring Bay Township | Woodford County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 41.5±3.7 | 40.4 | no clear change |
| Under 18 years | 19.8%±3.7 pts | 23.9% | – |
| 65 years and over | 18.3%±4.3 pts | 19.4% | – |
| Male | 49.9%±3.9 pts | 50.1% | – |
| Hispanic or Latino (any race) | 2.8%±2.7 pts | 2.1% | – |
| White alone, not Hispanic | 91.9%±4.0 pts | 93.5% | no clear change |
| Black or African American alone, not Hispanic | 0.0%±1.5 pts | 0.6% | – |
| Asian alone, not Hispanic | 0.1%±0.3 pts | 0.6% | – |
| American Indian and Alaska Native alone, not Hispanic | 0.3%±0.3 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0%±1.5 pts | 0.0% | – |
| Two or more races, not Hispanic | 4.9%±2.6 pts | 3.0% | – |
| Some other race alone, not Hispanic | 0.0%±1.5 pts | 0.2% | – |
| Born outside the United States | 2.2%±1.5 pts | 1.5% | – |
| Speak a language other than English at home (age 5+) | 2.3%±2.2 pts | 2.2% | – |
| Civilian veterans (age 18+) | 7.0%±2.8 pts | 6.3% | – |
| With a disability | 9.8%±3.0 pts | 10.6% | – |
| No health insurance coverage | 4.3%±2.1 pts | 5.2% | no clear change |
| High school graduate or higher (age 25+) | 87.2%±5.3 pts | 94.8% | – |
| Bachelor's degree or higher (age 25+) | 17.8%±5.1 pts | 35.9% | no clear change |
| Graduate or professional degree (age 25+) | 1.6%±1.1 pts | 13.0% | – |
| Lived in the same house a year earlier | 91.9%±5.1 pts | 92.3% | – |
| Moved from another state in the past year | 0.2%±0.3 pts | 0.8% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Spring Bay Township earn?
Half of Spring Bay Township's 1,013 households earn less than $75,846 a year (±$19,371), against $91,483 in Woodford County and $83,390 in Illinois. In 2015-2019 it was $80,251 in 2024 dollars; the margins of error cannot tell the two periods apart. 9.7% of residents live below the poverty line.
| Measure | Spring Bay Township | Woodford County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $75,846±$19,371 | $91,483 | no clear change |
| Mean household income | $89,095±$13,276 | $110,925 | – |
| Per capita income | $37,270±$4,547 | $44,140 | no clear change |
| People below the poverty line | 9.7%±3.8 pts | 7.0% | no clear change |
| Children under 18 below the poverty line | 6.9%±4.6 pts | 7.0% | – |
| Households receiving SNAP | 7.5%±3.3 pts | 5.5% | – |
| Households with a computer | 93.3%±4.6 pts | 94.4% | – |
| Households with a broadband subscription | 87.7%±5.1 pts | 87.7% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Spring Bay Township?
Owners occupy 85.3% of Spring Bay Township's occupied homes and renters 14.7%. The median owner-occupied home is valued at $169,100 by its owner (±$35,648). The median renter pays $923 a month including utilities, and 44.3% of renters pay 35% or more of their income on rent.
| Measure | Spring Bay Township | Woodford County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $169,100±$35,648 | $197,600 | no clear change |
| Median gross rent | $923±$166 | $912 | no clear change |
| Renters paying 35% or more of income on rent | 44.3%±16.4 pts | 31.2% | no clear change |
| Median monthly owner costs, with a mortgage | $1,455±$305 | $1,659 | – |
| Owner-occupied homes | 85.3%±4.4 pts | 85.7% | no clear change |
| Renter-occupied homes | 14.7%±4.4 pts | 14.3% | – |
| Housing units | 1,088±101 | 15,758 | −189 |
| Homeowner vacancy rate | 0.0%±4.2 pts | 0.3% | – |
| Rental vacancy rate | 3.2%±5.8 pts | 5.9% | – |
| Single-family detached homes | 91.1%±3.2 pts | 86.1% | – |
| Mobile homes | 4.4%±2.3 pts | 3.7% | – |
| Built 2020 or later | 0.0%±3.4 pts | 1.1% | – |
| Built 2010 to 2019 | 2.4%±1.5 pts | 5.6% | – |
| Built 1939 or earlier | 10.2%±5.8 pts | 18.3% | – |
| Households with no vehicle | 3.2%±1.7 pts | 3.3% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How do people in Spring Bay Township work and get to work?
76.0% of Spring Bay Township's workers drive alone. The average trip to work takes 22.1 minutes.
| Measure | Spring Bay Township | Woodford County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 66.4%±6.3 pts | 63.2% | – |
| Unemployment rate | 4.0%±2.8 pts | 3.5% | – |
| Drove alone to work | 76.0%±11.8 pts | 79.4% | – |
| Carpooled | 6.0%±3.8 pts | 6.5% | – |
| Public transportation | 0.0%±2.8 pts | 0.2% | – |
| Walked | 0.0%±2.8 pts | 1.7% | – |
| Worked from home | 17.8%±12.8 pts | 11.5% | – |
| Mean travel time to work | 22.1 min±3.2 | 25.0 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Spring Bay Township?
1 census tract lies mostly in Spring Bay Township, and 1 more reaches into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 305.02Woodford County | 2,255 | $65,556 |
| Tract 305.01Woodford County | 8,221 | $126,823 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Spring Bay Township) · Census block assignment files
How does Spring Bay Township compare with other places in Illinois?
By the Census Bureau's July 2025 estimates, Spring Bay Township is the 4,072nd-most populous of the 16,079 U.S. towns and townships that have one and the 371st-most populous of 1,407 in Illinois.
Spring Bay Township ranks 729th of 1,380 places in Illinois with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population, July 2025 estimate | 371st | 1,407 |
| Growth 2020-2025 (PEP) | 246th | 1,347 |
| Residents per square mile | 868th | 1,383 |
| Median household income | 729th | 1,380 |
| Per capita income | 760th | 1,383 |
| Median home value | 690th | 1,379 |
| Median gross rent | 691st | 1,280 |
| Poverty rate | 593rd | 1,119 |
| Bachelor's degree or higher | 1,014th | 1,369 |
| Median age | 637th | 1,383 |
| Owner-occupied share | 343rd | 1,382 |
| Travel time to work | 989th | 1,382 |
Spring Bay Township's figures with every place in Illinois (CSV)
Every place in Illinois, sortable · Compare Spring Bay Township with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Spring Bay Township?
18 of the 57 figures for Spring Bay Township on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Spring Bay Township are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.