Stormwater · Alamo Heights
The Bioswale
13 ft of channel · ~200 gal/hr · built 2025
Key
1SunflowerVolunteer, one season on
2ChannelTaking the storm
3Stone liningHill Country limestone
4Planted bankNatives on the slope
5The streetRunoff enters where it already wanted to travel
Before · nowhere to go
Cut and lined
In the stormThe Bioswale
Stormwater · Alamo Heights
- Prepared by
- NOONDesign ☉ Construction
- Issue
- 09.2026
- Studio
- San AntonioTexas Hill Country · Austin
- Sheet
- L-4
Design ☉ Construction · San Antonio & the Texas Hill Country · Hablamos español
Design narrative · Attachment A
The Bioswale
Not a bigger pipe. A place for the water to land.
01The idea
A street that flooded and then sat. The channel was cut along the curb exactly where the runoff already wanted to travel: thirteen feet, stone-lined, planted on the bank.
It does not resist the storm. It receives it, slows it against the rock, and lets the caliche drink.
02The channel
- Length
- 13 ft
- Absorbed
- ~200 gal/hr, field-observed
- Standing water before
- about 2,000 sq ft
- Built
- 2025, Alamo Heights
03Scope of the water work
The swale is shaped and armoured to carry ordinary rainfall and keep runoff off the walk. It is not sized to a design storm and it is not a substitute for drainage correction.
04What we do not use
- No decomposed granite in the channel. It migrates in rain and stains the walk.
- No crushed aggregate where water moves. Rounded stone only.
- No plastic or aluminum edging.
Reads withL-4 The Bioswale · R Register · C Begin
The Bioswale
Design narrative
- Prepared by
- NOONDesign ☉ Construction
- Issue
- 09.2026
- Studio
- San AntonioTexas Hill Country · Austin
- Sheet
- A
Design ☉ Construction · San Antonio & the Texas Hill Country · Hablamos español