Two Agencies, One Submittal
Fire flow for a Portland project runs through two bureaus, and missing either one stalls your permit. Portland Fire and Rescue reviews fire flow adequacy under Title 31, the city’s adopted version of the Oregon Fire Code. The Portland Water Bureau owns the distribution system: actual hydrant pressure and flow come from their network, and a flow test on a Portland Water Bureau hydrant is the baseline measurement that carries weight at plan review. Portland Fire and Rescue’s review focuses on whether the system can deliver adequate flow for the required duration. Portland Water Bureau’s role is confirming the actual capacity of the pipes and hydrants that serve the site.
We’ve operated a Portland office since 2018 and know both bureaus’ workflows. Our team coordinates with Portland Fire and Rescue’s Permit Center at 1300 SE Gideon Street and with Portland Water Bureau staff within the same project cycle, so you’re not managing two separate agency conversations on your own. If your project extends outside city limits, our civil engineers in the Portland area cover Beaverton, Hillsboro, Lake Oswego, Tigard, Tualatin, Gresham, Oregon City, and projects in Multnomah, Washington, and Clackamas counties.
What the Oregon Fire Code Requires
Oregon adopted the 2025 Oregon Fire Code, effective October 1, 2025, and Portland enforces it through Title 31 with local amendments. The fire code sets minimum required fire flow based on construction type, occupancy classification, and total floor area. That required flow figure then drives hydrant quantity, how close hydrants must sit to the structure, and whether the existing water main can sustain delivery under fire demand conditions.
The sprinkler question matters here. A fully sprinklered building can qualify for a reduction in required fire flow under the fire code. For some Portland infill projects, adding a sprinkler system is less expensive than the water main extension an unsprinklered required flow would demand. That trade-off is worth running through a hydraulic model before the project design locks in.
The Hydrant Flow Test
Every fire flow study we deliver starts with a hydrant flow test following NFPA 291. We record static pressure with no flow running, then residual pressure during a flowing test with a second hydrant open to simulate demand. From those two readings we calculate available flow at the required residual pressure.
Scheduling the test requires coordinating with the Portland Water Bureau to identify the flow hydrant and notify any affected neighbors, a step our field team handles as part of the standard scope. The test itself typically takes one to two hours on-site, and we schedule it to minimize disruption in Portland’s denser infill neighborhoods.
A hydrant flow test is a snapshot of system conditions at that date and time. We note the time of day, day of week, and surrounding demand conditions in the report because those factors affect repeatability and may come up at plan review.
EPANET Hydraulic Modeling
We build a calibrated EPANET model from the flow test results. EPANET lets us simulate the water distribution network under fire flow demand and confirm that the supply main, not just the nearest hydrant, can sustain the required flow for the duration the code specifies. This is where a test that looks adequate at the hydrant can reveal a bottleneck two blocks upstream on a smaller-diameter main.
For Portland projects where the existing supply falls short, the model identifies the limiting pipe segment and lets us evaluate upsizing options before the design commits to drawings. That analysis is part of the stamped report, not a separate engagement.
What the PE-Stamped Report Covers
The report we deliver includes:
- – Hydrant flow test data: static pressure, residual pressure, pitot pressure, and calculated flow rate per NFPA 291
- – Available fire flow at the required residual pressure for the test hydrant location
- – Required fire flow per the Oregon Fire Code for the proposed building type, construction class, and floor area
- – Calibrated EPANET model outputs and calibration notes
- – Available versus required comparison and a plain-language conclusion on adequacy
- – Upgrade recommendations when the supply falls short, with proposed improvements and a rough cost order of magnitude
Every report is stamped by an Oregon-licensed PE.
Start a Conversation
Call our Portland team at (503) 843-8211 to talk through your project. Give us the address, the proposed building area, the occupancy type, and any sprinkler information you have, and we can usually scope the study and quote a fixed fee that day. We’ve completed 400+ fire flow studies and Oregon is a core part of that practice.