FireApproved
On this page
  1. Why it matters
  2. How it works
  3. How the documents split
  4. The paths
  5. What people mix up
  6. How to check
  7. Limits
  8. Related records

Home / Guides / Site access and water / Rural firefighting water when there is no hydrant

Rural firefighting water when there is no hydrant

Last verified 2026-08-27.

Oregon fire-access guides still require an approved water supply under OFC 507.1. Yamhill’s 2025 guide and Portland’s 2021 guide both use 3,600 square feet as the residential split. Below that, Portland wants 1,000 gpm at 20 psi for one hour on a hydrant system. Without a competent water system, those same guides point at NFPA 1142 or a tank. This page does not print 1142 tank gallons. Confirm with the AHJ.

You are looking at a well, a pond, and a contractor who said “you need a 10,000-gallon tank.” The official is measuring fire flow, not a blog gallon. The hydrant, the tank, and the sprinkler are different objects.

No g3-passed exhibit matches this object. SIT-100 names water and tanks on the hub. DET-023 is deferred until a public 1142 table opens. Do not invent the tank.

Why it matters

A house that meets R327 covering can still fail the fire-flow look. The engine that reached the driveway still needs water. Fire apparatus access is how they get there. This page is what they draft or pump.

How it works

Fire flow is gallons per minute at a residual pressure, usually 20 psi in these guides. A municipal hydrant system is one way to deliver it. A tank, a reservoir, or a draft hydrant on a pond is another. NFPA 22 is how Yamhill tells you to install a private fire-protection tank. NFPA 1142 is the rural calculation method those guides name when the hydrant system is not there. The 1142 body is paywalled here. The county guide is not a license to reprint Chapter 4.

How the documents split

ObjectYamhill 2025Portland 2021 PFCLincoln 2022 OFC form
Always requiredOFC 507.1 approved supplySame chapter in that guideRequired for all structures
Competent hydrant, R-31,000 gpm at 20 psi1,000 gpm at 20 psi for 1 hour if ≤3,600 sq ftUrban path is OFC App B/C/D
Competent hydrant, other buildings1,500 gpm at 20 psiAppendix B tables; sprinkler floor 1,000 or 1,500 gpmUrban path
No competent system≥3,600 sq ft uses B107 methods (1142, IWUIC, ISO)NFPA 1142 2017 (B107.1)≥3,600 sq ft including garage and porches, plus all commercial, uses 1142
Tank standard namedNFPA 22 (OFC 507.2.2)Not numbered as 22 on the rural lineContact FD for draft specs
Sprinkler as alternateUACS OAR 918-480-0125Rural note: sprinkler supply can be the only waterNFPA 13 / 13R / 13D may be acceptable
PoolNot creditedNot creditedNot credited

Prescott is a separate local path. Its current 404.1 requires an approved water supply capable of the required fire flow, but the published amendment does not print a tank volume or the Oregon 3,600-square-foot split. The local official still has to name the fire flow and acceptable supply.

The paths

1. Ask whether a hydrant already delivers the flow. Yamhill’s “adequate and reliable” definition is 1,500 gpm at 20 psi. Portland’s one- and two-family number below 3,600 square feet is 1,000 gpm at 20 psi for one hour. Those are not the same sentence. Use the guide that binds the lot.

2. Measure fire area the way Yamhill writes it. Living space plus attached garage or shop, covered porches or decks, usable attic or basement. A “house under 3,600” that forgot the garage is how the rural method appears.

3. If there is no competent system, the official picks the method. Yamhill lists NFPA 1142, IWUIC, and ISO needed fire flow under B107. Portland names NFPA 1142 2017. Lincoln names 1142 for rural residential over 3,600 square feet. This page does not calculate gallons.

4. A tank is a listed installation, not a farm cistern. Yamhill: private fire-protection tanks per NFPA 22. Draft hydrants get jurisdiction-specific ports. Do not copy a strainer-hole recipe from an unopened standard.

5. Sprinkler is an alternate, not a secret. Portland’s rural note is the clearest skip of a separate fire-flow tank when a sprinkler is the supply. Yamhill and Lincoln send you to UACS or to 13/13R/13D as an acceptable alternative. The building official keeps UACS.

6. Prescott publishes the obligation, not the gallons. Use the City’s current 404.1 to identify the approved-water-supply requirement. Ask the official for the required fire flow and acceptable source; do not fill the missing number from an Oregon comparison.

7. Insurance PPC is a sibling. ISO Public Protection Classification scores community structure-fire suppression, including water. It is not OFC 507.1.

What people mix up

  • A blog gallon count as NFPA 1142.
  • A swimming pool as fire flow.
  • 3,600 square feet as floor area without the garage.
  • Portland’s 1,750 gpm WUI number as statewide OFC.
  • A sprinkler as an automatic skip without the official.
  • This water look as an R327 covering inspection.

How to check

  1. Name the fire district. Open their access-and-water guide.
  2. Ask if the lot is on a competent hydrant system. If yes, write the gpm they want at 20 psi.
  3. Add garage, porches, and usable attic to the square footage.
  4. If they say “tank” or “1142,” ask which edition and which installation standard (Yamhill names NFPA 22). Do not take gallons from this page.
  5. If they offer UACS or a 13D trade, that is OAR 918-480-0125 and the building official.
  6. Confirm. Do not install a pond fitting the district cannot draft.
  7. In Prescott, ask the official to identify the required fire flow and approved supply because the opened local amendment does not print a tank volume.

Limits

This page does not size a tank. NFPA 1142 and NFPA 22 bodies were not opened. DET-023 stays deferred. FireApproved is not the fire district. The official who will sign the water-supply line owns the gallons.

Questions

Does every rural house need a water tank?

No. Yamhill’s 2025 guide says an approved water supply capable of the required fire flow shall be provided (OFC 507.1). Type of supply can be reservoirs, pressure tanks, elevated tanks, water mains, or other fixed systems (OFC 507.2). A hydrant on a competent system can be that supply. A tank is the usual path where there is no such system. The official names which path.

What is 3,600 square feet doing here?

Portland’s 2021 fire-code guide sets 1,000 gpm at 20 psi for one hour for one- and two-family dwellings not exceeding 3,600 square feet on a hydrant system, then sends larger dwellings to OFC Appendix B Table B105.1(2). Yamhill’s guide uses 3,600 square feet as the line where dwellings without a municipal or competent water system get the rural methods, including NFPA 1142. Lincoln’s form uses the same 3,600 square-foot rural trigger. Fire area on Yamhill’s page includes the garage, porches, and usable attic.

Can I count the swimming pool?

None of the Oregon guides opened for this page credit a pool as fire flow. Do not invent a draft fitting. Yamhill tells you to contact the serving fire jurisdiction for draft-port location, size, and connection type if you install a draft hydrant.

Does a sprinkler delete the tank?

Portland’s rural-fire-flow note says structures protected by an automatic sprinkler system are not required to have a water supply other than that required to supply the sprinkler. Yamhill points at OAR 918-480-0125, the uniform alternate construction standard, when access and water cannot be resolved under OFC 104.2.3. That is the building official’s call with the fire official’s input. Not a DIY skip.

Does Prescott's current WUI code publish a tank size?

No. Prescott 404.1 requires an approved water supply capable of the required fire flow for facilities and buildings constructed or moved within the jurisdiction. The opened City chapter does not print a tank volume or rural calculation in that amendment. Do not import Oregon's 3,600-square-foot split or an NFPA 1142 gallon count into Prescott.

Sources