---
path: industries/cities-and-government
title: Cities and Government
desc: Answer planning questions with your council's own published layers.
date: Oct 21, 2026
---

# Answer planning questions with your council's own layers

Most councils already publish their data as ArcGIS REST services. This example takes two of Christchurch City Council's layers from the Data Hub, its schools and its modelled 200-year flood extent, and finds the schools within 200 metres of the flood.

## Christchurch schools near the 200-year flood extent

**Data:** Christchurch City Council's schools and its modelled 200-year flood extent, both public ArcGIS REST layers (CC BY 4.0), added from the Data Hub
**Method:** simplify the flood extent to 5 m, buffer it by 200 m, merge the buffer into one shape, and keep the schools that touch it

```text
Receipt on "Flood extent, 200-year"
1. simplify   5 m
Receipt on its result
2. buffer     200 m
3. dissolve   one shape
4. simplify   5 m
Receipt on "Schools"
5. intersect  with the result of 2–4
```

The council's flood model is too detailed to overlay as published, so it is simplified to 5 m first; only a school within a few metres of the edge could change sides. The buffer is measured in metres, whatever the layer's projection.

```map
christchurch-schools-near-flooding
zoom=10.5
```

## Run it on your data

Add a layer by URL from a public ArcGIS, WMS or OGC API service, or upload your own files, then run the same buffer and intersect against the facilities you are responsible for: clinics, care homes, pumping stations. Export the finished map to QGIS when the work continues on the desktop. See [adding data by URL](/docs/upload-anything/urls).


## Frequently asked questions

**Can I add a layer from our own ArcGIS Server?**

Public services, yes: add them by URL\. Services that need a token or a login can't be added yet\.

**How current is a public layer?**

As current as its source\. The map records when the layer was fetched; saved queries can refresh on an interval\.

[saved queries](</docs/owl-ai/ai-sql-queries>)


## Next step

- [Open the map in the gallery](/gallery?industry=cities-and-government)
- [Add a layer by URL](/docs/upload-anything/urls)
- [Book a demo](/demo)