Reader-supported. GopherTrunk is free, open-source software. Some
hardware links on this page go to Amazon with our Associates tag
(gophertrunk-20); if you buy through them we may earn a small
commission at no extra cost to you. Links to out-of-production gear may go to
eBay searches instead; we have no affiliate relationship with eBay and earn
nothing there. It never changes which gear we recommend, and
the software stays free either way. How GopherTrunk is funded →
Water Off or Flooding the Street? Water Main Breaks Explained
Sudden low pressure plus water surfacing anywhere it shouldn’t is a main break — call the utility’s emergency line and don’t assume someone else has, because utilities locate breaks from the calls they get. Here’s the diagnosis path, what to do inside your house while it’s out, and the honest translation of a boil-water advisory.
Key takeaways Diagnose: neighbors dry too = main/system; just you = your line or valve. Report: utility emergency line (24/7); 911 too if a road or structure is threatened. Protect the house: don’t run hot water while pressure’s off; flush the cold tap nearest the meter when it returns. Boil-water advisory = rolling boil 1 min for anything you swallow, until officially lifted. Hydrant blasting on a calm day = scheduled flushing, not a break. The dispatch angle: breaks, closures, and flushing all run over public-works and dispatch radio.
The two-minute diagnosis
- Cold tap dead or trickling? Ask one neighbor. Both dry → system problem; just you → your shutoff valves, meter valve, or service line.
- Look and listen outside: water in the gutter on a dry day, a wet sinkhole forming, the hiss of pressurized water — walk the block before you call, because “water visible at [address]” beats “my water’s off” for dispatching a crew.
- Check the utility’s alerts page/social feed for known breaks and planned work; then call the emergency number anyway if your street isn’t listed — outage maps for water are far worse than electric ones, and calls are the sensor.
- Escalate to 911 only when water is undermining pavement (cars + voids under asphalt end badly), entering buildings, or anywhere near electrical equipment.
Inside the house: while it’s off, and when it returns
- While it’s off: avoid running hot taps (a draining water heater can burn out its elements), skip the dishwasher/laundry, and keep a filled kettle’s worth for hand-washing. Toilets: one bucket of any water poured into the bowl flushes it.
- When pressure returns: expect air spitting and brown water — sediment, not sewage. Run the cold tap nearest the meter until clear, then the rest; clean aerators if flow stays poor; hold laundry until water runs clear (iron stains set permanently).
- Under a boil-water advisory: rolling boil for one minute for drinking, cooking, ice, coffee, and teeth; bottled works too. Shower with mouth closed; sanitize-cycle dishwashers are fine. Dump ice made during the advisory. It lifts after consecutive clean samples — usually a day or two, announced the same ways it was issued.
The false alarm that fools everyone: hydrant flushing
A hydrant roaring into the street with a bored utility worker beside it is scheduled flushing — deliberate scouring of the mains that also causes the pressure dip and brown-water burst that make half the neighborhood think “break.” Utilities post schedules, and the work is coordinated over public-works radio, which is exactly how scanner listeners settle “break or flush?” in ten seconds. Water utilities, public works, and the police units closing the street all talk on channels the frequency reference covers — and the kit below hears every one of them, alongside the rest of this cluster’s mysteries.
The fix for next time: a scanner that never sleeps, for about $250
Every lookup method on this page depends on someone else — a feed volunteer, an app's coverage map, an agency webmaster. This kit removes the middleman: a silent little box on a shelf that decodes your county's digital dispatch directly off the air, streams it to any browser in the house, and records every call with timestamps. Next time the sirens go past, the answer is already on your phone — and free, open-source GopherTrunk is the software, so the parts below are the entire cost.
Why two receivers: one dongle stays locked to your police trunked system while the second covers fire/EMS or a neighboring system at the same time — the two channels a "what's going on?" moment actually needs. That's a trick a $500 handheld scanner can't do, and GopherTrunk drives both dongles from one Orange Pi.
Orange Pi 5
around $90
The RK3588 host that runs it all 24/7 — silent, low-power, and strong enough for both dongles with headroom to spare. GopherTrunk ships a native ARM64 Linux build for it.
Orange Pi 5 on Amazon →RTL-SDR Blog V4 kit
around $55
The dongle and the telescopic dipole antenna kit with coax and mounts in one box — this one holds your police system's control channel.
V4 + antenna kit on Amazon →RTL-SDR Blog V4 (second dongle)
around $35
Covers fire/EMS, a second trunked system, airband, or NOAA weather — simultaneously, not by giving up the first channel.
RTL-SDR V4 on Amazon →The complete parts list
| Part | Why it's in the kit | Approx $ | |
|---|---|---|---|
| Orange Pi 5 | Always-on host for both dongles | ~$90 | Amazon → |
| RTL-SDR Blog V4 + dipole antenna kit | Receiver #1, antennas, coax, mounts | ~$55 | Amazon → |
| RTL-SDR Blog V4 (second) | Receiver #2 — fire/EMS or a second system | ~$35 | Amazon → |
| Powered USB 3.0 hub | Clean, stable power for two warm dongles | ~$35 | Amazon → |
| 16-piece SMA adapter kit | Joins any antenna to any dongle, first try | ~$18 | Amazon → |
| RG316 SMA pigtail kit | Flexible jumpers between hub, dongles, antennas | ~$15 | Amazon → |
| USB-C power supply (5V/4A+) | The Orange Pi 5 needs solid power for 24/7 duty | ~$15 | Amazon → |
| microSD card (64GB, A2) | OS plus months of recorded calls | ~$12 | Amazon → |
Kit total: about $250–275. Worthwhile upgrade once it's earned a permanent shelf: an outdoor discone antenna (~$40) that hears everything from 25–3000 MHz — see the antenna guide. Prefer a Raspberry Pi 5 host instead? Same build, swap the board — Pi 5 (8GB) on Amazon and the SBC build guide.
From boxes to first decoded call
- Flash 64-bit Linux (Debian/Ubuntu image) to the microSD and boot the Orange Pi headless.
- Plug in the powered hub, both dongles, and the antennas — the adapter kit bridges any connector mismatch.
- Install GopherTrunk — one free static binary, no dependencies: download, then follow the setup guide to point it at your county's system from RadioReference.
- Open the web console from any phone or laptop in the house — live calls, talkgroup names, and a scrollable, replayable recording archive.
Two honest caveats before you spend a dime: check RadioReference that your agencies are not encrypted — no device decodes AES — and skim the legality rules for your state (listening is legal in the US; a few states restrict use in vehicles). Rather have a no-computer, pocketable option instead? That's the dedicated scanner guide.
Frequently asked questions
Why is my water suddenly off or at a trickle?
The usual causes: a water main break nearby (often with water visibly surfacing in a street or yard), an emergency shutoff while crews repair one, planned maintenance you missed the notice for, or — if it’s just you — your own service line or a closed valve. Check your utility’s alerts page or social feed, ask a neighbor whether they’re dry too, and report it: utilities map outages from calls.
Water is bubbling up through the street — who do I call?
The water utility’s emergency line (24/7, on their website and your bill) — main breaks waste enormous volumes and undermine pavement fast, so they want the call. If the water is undermining a roadway, flooding structures, or near downed electrical equipment, call 911 as well; police close the street while the utility digs.
Is brown or discolored water after a main break safe?
Discoloration is usually stirred-up sediment from the pressure change — unpleasant but typically not dangerous. Run the cold tap nearest the meter for several minutes until clear, avoid running hot water first (it pulls sediment into your water heater), and hold off on laundry — iron sediment stains fabric. If a boil-water advisory is issued, that supersedes everything: follow it.
What does a boil-water advisory actually require?
When a break drops system pressure, contaminants can seep in, so until tests come back clean: boil water (a rolling boil for one minute) before drinking, cooking, brushing teeth, or making ice — or use bottled. Showering is generally fine for healthy adults (don’t swallow); dishwashers on a sanitize/hot cycle are okay. The advisory lifts only after two rounds of clean samples, typically 24–48 hours.
Why is a hydrant open and blasting water with no emergency?
Scheduled hydrant flushing — utilities deliberately open hydrants to scour sediment from mains and verify fire flow. It looks like a main break and briefly causes the same pressure drop and discoloration. Utilities post flushing schedules; it’s also chattered about on public-works radio channels, which is how scanner listeners tell a flush from a break without leaving the couch.
How long does a water main repair take?
Typically 4–8 hours from crew arrival for a routine break — locate other utilities, dig, clamp or replace the section, disinfect, restore pressure, then repave later. Big transmission mains or breaks tangled with gas and electric lines run longer. The utility’s outage page and the crew activity on the street are your real progress bar.