Quick answer: The Leaf River reaches flood stage at Hattiesburg (gage HATM6) at 22 feet, with major flooding at 29.3 feet. Its record crest is 34.03 feet, set in the April 1974 flood of record. River flooding builds slowly and is forecastable — watch it live at water.noaa.gov/gauges/hatm6 — while flash flooding arrives fast. Both bring contaminated outside water into homes.
If you own a home near the water in Hattiesburg or Petal, the Leaf River is the single biggest natural factor in your flood risk. It has a long, well-documented flood history, a public gage anyone can read, and a personality worth understanding before the water rises. Here’s what the record shows.
The Leaf and the Bouie: Hattiesburg’s Rivers
Hattiesburg sits at a river junction. The Leaf River runs along the city’s eastern edge — it’s the boundary between Hattiesburg and Petal — and its main local tributary, the Bouie River, joins it right at Hattiesburg in the northwestern part of Forrest County.[3] Together they drain into the broader Pascagoula River basin on the way to the Gulf. When people talk about Hattiesburg flooding, this is the system they mean: two rivers converging next to a populated area, gathering runoff from a wide watershed upstream.
Because the Leaf forms the Hattiesburg–Petal line, the same river crest is a shared event for both cities — a fact reflected in the USGS flood-inundation study for this reach, produced with both cities and Forrest County.[5]
Reading the Gage: Flood Stages on the Leaf
The Leaf River at Hattiesburg is monitored by the gage the NWS calls HATM6 (USGS site 02473000), in service since 1905. The Weather Service defines four thresholds for it:[1]
| Stage | Height | What it means |
|---|---|---|
| Action | 16 ft | Prepare — the river is rising toward flood |
| Flood stage (minor) | 22 ft | Minor flooding of low-lying areas begins |
| Moderate | 24 ft | More significant flooding of property |
| Major | 29.3 ft | Extensive, dangerous flooding |
Those numbers are the vocabulary of every flood forecast you’ll hear locally. When the NWS says the Leaf is “forecast to crest at 25 feet,” you now know that’s into moderate-flood territory — above the 22-foot flood stage, below the 29.3-foot major mark.
The 1974 Flood of Record — and Other Notable Crests
The Leaf’s benchmark is the record crest of 34.03 feet, set on April 15, 1974 — more than four feet above the major-flood threshold and still the highest on record.[1] The NWS keeps a long crest history for the gage; the most notable are:
| Crest | Date |
|---|---|
| 34.03 ft (record) | April 15, 1974 |
| 31.53 ft | February 23, 1961 |
| 29.19 ft | April 9, 1983 |
| 29.13 ft | April 14, 1980 |
| 28.91 ft | March 22, 1943 |
| 27.51 ft | March 12, 2016 |
The pattern is worth noting: the Leaf’s biggest floods cluster in late winter and spring, when saturated ground and heavy regional rain stack up. It doesn’t take a hurricane — most of these crests came from ordinary seasonal weather systems parked over the watershed.
River Flooding vs. Flash Flooding: Why It Matters to You
For a homeowner, the two kinds of flooding call for very different responses.
- River flooding is the slow kind. The Leaf rises over hours to days, and because the gage and NWS forecasts give warning, you often have time to move belongings up, protect valuables, and decide whether to leave. It’s the flooding you can see coming.
- Flash flooding is the fast kind — intense rain overwhelming streets, drainage, and small creeks, sometimes with little notice. It’s the reason a home nowhere near the Leaf can still take on water.
What they share is what matters for cleanup: both bring outside water into the house, which under the water damage categories is contaminated (Category 3) water — a different, more hazardous job than a clean-water pipe leak. That’s true whether you’re inside a mapped flood zone or not.
How to Watch the River Yourself
You don’t need special tools to keep an eye on the Leaf. The NWS publishes a free, continuously-updated page for the gage at water.noaa.gov/gauges/hatm6, showing the current level and the forecast against those flood thresholds.[1] For the tributary, the Bouie Creek near Hattiesburg gage (HBGM6) does the same,[4] and the underlying USGS real-time data is public too.[2] Watching the forecast when heavy rain is coming is the cheapest flood protection there is.
Knowing the river is half of it; the other half is what to do when it reaches you. If the Leaf or a flash flood puts water in your home, see The First 24 Hours After Flooding, and reach our flood cleanup crew any time — a real person answers, day or night.
Frequently Asked Questions
The National Weather Service sets the Leaf River flood stage at Hattiesburg (gage HATM6) at 22 feet, where minor flooding begins. Action stage is 16 feet, moderate flooding is 24 feet, and major flooding is 29.3 feet. You can watch the current level and forecast any time at the NWS page for the gage.
The record crest at Hattiesburg is 34.03 feet, set on April 15, 1974 — well into major-flood territory and still the flood of record. The next-highest crest, 31.53 feet, came in February 1961. Both are far above the 22-foot flood stage.
River flooding builds over hours to days as a swollen river like the Leaf slowly rises past flood stage — it's forecastable, and the gage gives you warning. Flash flooding is sudden, from intense rain overwhelming drainage or small creeks, and can arrive with little notice. Around Hattiesburg you can face both, and both bring contaminated outside water into a home.
Use the National Weather Service's public river page for the Leaf River at Hattiesburg (water.noaa.gov/gauges/hatm6), which shows the observed level and the forecast. The Bouie Creek gage near Hattiesburg (HBGM6) covers the Leaf's main tributary. Both are free and update continuously.
Sources
- NOAA/NWS National Water Prediction Service — Leaf River at Hattiesburg (HATM6)
- USGS — Leaf River at Hattiesburg, MS (02473000)
- USGS — Leaf River above Bouie River at Hattiesburg (02472375)
- NOAA/NWS — Bouie Creek near Hattiesburg (HBGM6)
- USGS — Flood-Inundation Maps for the Leaf River at Hattiesburg (SIM-3300)