This is Turntide's first public, source-linked practice question. It was prepared by an AI assistant from the linked public sources, without copying member conversation. A human has not reviewed a site or agreed to a trial.
The question
Where does rain run off a roof or paved surface in your area, and could a rain garden safely receive some of it? A useful local answer needs to identify the runoff source, the receiving area, soil and drainage conditions, the route of overflow, nearby buildings and utilities, maintenance responsibility, and applicable local rules. Do not post an exact home address or another person's location to answer it.
What the sources support
The US Environmental Protection Agency's green infrastructure guide describes rain gardens as shallow planted areas that collect and filter stormwater runoff. Its rain garden resource index points to regional guides for siting, design, installation, and maintenance. EPA labels that resource index as general information that is no longer being updated, so a local guide and current local rules still need checking. Those sources support considering a rain garden as a stormwater practice. They do not establish that a particular property is suitable or that a Turntide installation has reduced flooding.
A measured result elsewhere
The US Geological Survey's Gary, Indiana study monitored a City Hall parking-area intervention before and after construction of a central rain garden over sandy soil during the spring, summer, and fall of 2016–18. USGS reports that the share of study-area precipitation discharged to the sewer fell from about 25 percent before construction to 2 percent after, an estimated 80.3 percent reduction in stormwater discharged to that sewer. The study measured that site and intervention; it does not predict the effect of a different garden, soil, or storm. In a separate USGS project account, green infrastructure over clay soils in Detroit showed little stormwater-volume reduction. These findings make soil and drainage conditions part of the local question. They are external field evidence, not a Turntide field outcome.
Rainfall evidence still needed
For a United States site, NOAA's Precipitation Frequency Data Server can provide Atlas 14 precipitation frequency estimates and uncertainty for a selected location. An estimate can help frame a design question; it is not a record of a storm at the site or proof that a proposed garden can safely receive runoff. A local answer still needs an observed drainage path, site conditions, an appropriate local design guide, and a human decision about any trial. No location has been selected and no rainfall estimate has been calculated for this Turntide question. Share only a broad locality in public Discord; discuss exact site details privately with a consenting organizer if a trial is proposed.
Evidence and outcome
- Turntide evidence state: conceived, with external guidance and monitored
field evidence from other sites linked. No Turntide simulation, field trial, or independent replication is recorded.
- Source check: the linked EPA, NOAA, and USGS pages were read on 2026-09-27.
- Vault work: the source trail in `#receipts`,
rainfall-source update, USGS field-study receipt, and agent-prepared reading path in `#vault-briefings` link back to this record. Neither is a human review or a field result.
- Community outcome: [the question was posted in
#question-quarryon
2026-09-27](https://discord.com/channels/1184863861065658419/1396155279208484997/1553932671808307200). An invitation for a human source-review lead or gathering host was posted in #mainland. A source-review request in `#archive-desk` now has a specific USGS study-check follow-up, and observation invitation in `#garden-grove` now point to this record. No human source review, local answer, accepted host, or session is recorded here yet.
- Field outcome: unknown. No before-and-after observation has been
submitted or witnessed.
Help improve this record
Join Turntide, choose Questions and research in Discord's onboarding, and complete the #dock welcome. Then bring a source or a general, non-identifying observation to #question-quarry. Say what you observed, what you infer, and what remains unknown. Mentioning the research bot sends that question to NVIDIA inference for a reply in Discord; ordinary posts are not sent there by this service. A source link can be evaluated without copying your words into this site. If your own words or field observation would be useful in a public revision, a steward must first ask what may be published, how you want to be credited, and whether a location should be generalized. Posting in Discord alone gives no publication permission. A proposed trial needs its own human organizer, site-specific protocol, and witnessed result before this record's evidence state can change.