Methodology
This atlas exists to give an honest, neighborhood-level picture of Des Moines — one that helps residents, buyers, and neighbors understand a place without flattening it into a single “good” or “bad” score. Every choice below is made in service of that goal: describe each neighborhood on its own terms, surface trade-offs rather than hide them, and avoid methods that quietly reproduce the patterns of redlining.
How neighborhoods are defined
We work with the 51 recognized Des Moines neighborhoods. Every measure on this site is reported at that neighborhood level.
Parcels and amenities are assigned to a neighborhood by location, not by name. Each point or parcel is placed inside the neighborhood polygon that geometrically contains it (a spatial “within” test), rather than matched on a text label. Name-matching breaks down when a neighborhood spans multiple zones or when source records spell things inconsistently; the spatial approach gives clean, complete coverage across all 51 neighborhoods.
Data sources
| Topic | Source |
|---|---|
| Parcels, land use, assessed values | Polk County Assessor |
| Race, ethnicity, and population | U.S. Census, ACS 5-year [fill in vintage, e.g. 2019–2023], table B03002 |
| Cultural, entertainment, and retail venues | OpenStreetMap, via the Overpass API |
| Property tax levies | Polk County Auditor levy records |
| Residential rollback | Iowa Department of Revenue |
All sources are public. Where a source is updated on a fixed schedule (ACS annually, the assessor on reassessment years), the data shown reflects the most recent extract we have processed; see Limitations below.
What each measure shows
Each lens on the map describes one dimension of a neighborhood. They are meant to be read side by side, not added together.
Home value — the typical assessed value of residential parcels in the neighborhood, from Polk County Assessor records. This reflects what the assessor values homes at, which tracks but is not identical to sale prices.
Median sale — the middle sale price of homes that actually changed hands, from recorded residential sales. Because it counts only homes that sold, neighborhoods with few recent sales rest on a smaller, noisier sample.
Walkability — the density of everyday destinations you could reach on foot, measured as destinations per square mile. Higher means more shops, services, and gathering places packed into walking distance; lower means a more spread-out, car-oriented area.
Culture — access to cultural venues: museums, galleries, theaters, and arts centers. We count these from OpenStreetMap within each neighborhood plus a roughly quarter-mile walk around its edges (about a five-minute walk), then express the result as a 0–100 score relative to the other neighborhoods.
Entertainment — access to nightlife and dining: bars, pubs, nightclubs, cinemas, restaurants, and cafés. Counted and scored the same way as Culture, over the neighborhood plus its quarter-mile walk buffer.
Retail — access to shops of all kinds, from groceries to specialty stores. Same counting and 0–100 scoring approach as the other amenity measures.
Racial diversity — how mixed a neighborhood is across race and ethnicity, summarized with a Simpson diversity index (explained in detail below).
Economic diversity — the spread of household incomes within a neighborhood, so that a place with a wide range of incomes reads as more economically mixed than one where nearly everyone earns about the same.
Poverty rate — the share of residents living below the federal poverty line, from ACS estimates.
A note on the three amenity scores (Culture, Entertainment, Retail): because they use a quarter-mile walk buffer, a neighborhood gets credit for venues just across its border, not only those strictly inside it — which is how people actually use amenities. And because the scores are relative to the rest of Des Moines, an 80 means “well-served compared with other DSM neighborhoods,” not a fixed absolute standard.
How the racial diversity score works
Demographic diversity is summarized with a Simpson diversity index — the probability that two people drawn at random from a neighborhood belong to different groups. With the eight mutually exclusive groups in table B03002, the index has a theoretical maximum of 0.875 (a neighborhood split perfectly evenly across all eight groups).
We rescale each neighborhood’s index against that 0.875 ceiling, not against the other neighborhoods. This is a deliberate choice: the score reflects a neighborhood’s absolute mixing relative to what’s possible, rather than its rank within Des Moines. A neighborhood doesn’t look more or less diverse simply because of how the rest of the city looks.
What this atlas deliberately does not do
We do not combine these measures into a single composite “neighborhood score,” and we do not rank neighborhoods against one another.
Composite scores feel convenient, but they smuggle in a value judgment about what counts as “good” — and the answer is rarely the same for everyone. High assessed values read as desirable to a seller and as a barrier to a first-time buyer; the same number points two directions at once. Rankings, layered on top, tend to track income and reproduce the geography of historical disinvestment. Rather than encode one definition of “good” for the whole city, we present each measure on its own and let you weigh what matters to you.
Limitations and honesty notes
- Assessed-value change over time is not shown yet. Producing a trustworthy trend requires dated parcel extracts from multiple reassessment years joined parcel-to-parcel. The change visible in a single combined extract is largely a rollback artifact, not real revaluation, so we have chosen to omit it rather than mislead.
- ACS figures are estimates with margins of error, and those margins widen for small populations. Treat small differences between neighborhoods as noise.
- OpenStreetMap is not exhaustive. Amenity counts reflect what has been mapped, which is very good in dense areas and incomplete at the edges.
- Everything here is a point-in-time snapshot. Neighborhoods change faster than annual data can capture.
Technical notes
Spatial work is done in a projected coordinate system suited to central Iowa (EPSG:3422) and reprojected to EPSG:4326 for web display. The pipeline is built in R, with the interactive map rendered through Leaflet and the site published with Quarto.
This methodology will be updated as new data is incorporated and as the measures evolve. Questions or corrections are welcome.