# APL: Pattern 4; Agricultural Valleys

> Urban development has the high ground over agricultural and ecological preservation — and it should! *A Pattern Language* annotations on Pattern 4: Agricultural Valleys

- Page: https://blog.chaoticgood.computer/content/annotations/a-pattern-language/04-agricultural-valleys
- Author: Spencer Elkington
- Published: 2026-02-08
- Updated: 2026-02-08
- Tags: engineering/data, projects/games/the-neighborhood, projects/a-pattern-language, writing/annotations

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← [City Country Fingers](https://blog.chaoticgood.computer/content/annotations/a-pattern-language/03-city-country-fingers) | [Lace of Country Streets](https://blog.chaoticgood.computer/content/annotations/a-pattern-language/05-lace-of-country-streets) →

> [!quote] Quote
>
> … this pattern helps maintain the [01-independent-regions](https://blog.chaoticgood.computer/content/annotations/a-pattern-language/01-independent-regions) by making regions more self-sufficient agriculturally; and it will create [03-city-country-fingers](https://blog.chaoticgood.computer/content/annotations/a-pattern-language/03-city-country-fingers) almost automatically by preserving agricultural land in urban areas. But just exactly which land ought to be preserved, and which land built upon?
>
> — *[A Pattern Language](https://blog.chaoticgood.computer/tags/projects/a-pattern-language)*

## Notes

Finally — a pattern that won’t take an hour!

This pattern is largely related to the interaction between development and geography. Specifically, it makes the case that valleys — low ground — should be preserved for agricultural activity, while higher ground should be reserved for developments.

I do see how this can directly relate to [03-city-country-fingers](https://blog.chaoticgood.computer/content/annotations/a-pattern-language/03-city-country-fingers) — it was a footnote, but we did see an interesting pattern in an area of St. Louis related directly to this:

![Pasted image 20260207174951](https://blog.chaoticgood.computer/_astro/Pasted%20image%2020260207174951.DI9KDb6Z_uWpVE.webp)

It’s a pretty well-known fact that water flows downward. We can assume, then, that the small creeks and offshoots flowing into the Meramec river from these examples are on a lower ground than their directly-adjacent development. While these may not be *agricultural* valleys, per se, it does still demonstrate the pattern of leaving lower-laid land undeveloped (or lightly developed) compared to the directly-adjacent higher ground.

A (crude) overlay of the topological map of the area, retrieved from the [United States Geological Survey](https://ngmdb.usgs.gov/topoview/viewer/#13/38.5677/-90.5124), seems to give some backing to this claim:

![Pasted image 20260208145652](https://blog.chaoticgood.computer/_astro/Pasted%20image%2020260208145652.yI0aFEXS_rVGIV.webp)

We can see clearly that many of the areas on lower-laying land — not just directly adjacent to the Maramec itself, but adjacent to its many tributaries embedded in development — remain labelled as greenlands.

As an extra data point, to try and explain what we saw in the [03-city-country-fingers](https://blog.chaoticgood.computer/content/annotations/a-pattern-language/03-city-country-fingers) analysis of Salt Lake City:

![Pasted image 20260208151035](https://blog.chaoticgood.computer/_astro/Pasted%20image%2020260208151035.BlFllWBX_QL6Kq.webp)

Using the same (*very* crude) overlay, I think this illustrates the point. While we do have some water features — the City Creek watershed, Parley’s Creek, Emigration Creek, etc. — it could hardly be said that they have the necessary tributaries to a) penetrate very deep into Salt Lake City, proper and b) don’t have enough of a fractal surface area to have preserved, by geography, the city-country finger pattern via agricultural valleys.

It’s interesting: when folks from St. Louis come to visit in Salt Lake, they talk about verticality. While the mountain view is undeniable, tributaries might create more variance in elevation — and finer fractal fingers — than a single large mountain would.