St. Marks River at St. Marks (in MHHW)
Future / Actual / Minor
OWP 2.0 WWA Modal Title
01/11/2021, 10:04 PM UTC through 01/11/2021, 10:04 PM UTC
Sender
Sent
- Downstream gauge unavailableWarning: no valid ratings curve available. Transformations to and from FEET/CFS/KCFS will not happen.
Traces and Thresholds Click to turn on/off display
Observed (OBS) 06/09/2025 8:20 AM EDTLow Threshold: -5.3 ftCATEGORY STAGE 
Major Flooding 5.1 ft Moderate Flooding 3.4 ft Minor Flooding 2 ft Action 1.2 ft Reliability of the Forecast:
NOTE: Forecasts are issued routinely year-round.
Water levels are referenced to the Mean Higher High Water (MHHW) Datum. This datum can be used to approximate sea water inundation of normally dry ground near the coast. For specific impacts, please refer to the statements on this page.
Gauge reading affected by tides.
National Water Model Hydrograph
Official NWS streamflow forecasts are produced by NWS hydrologic forecasters for river gauge locations using hydrologic models which are calibrated to that location. This process considers additional guidance and information, including local expertise and experience, to produce the best forecast possible. The NWM output provides supplemental guidance to NWS forecasters and should not be considered an official NWS river forecast.
Flood Impacts
- 12.1 - Flooding of historic proportions. Most of the town of St. Marks floods up to the second story. Water may extend as far inland as Commerce Blvd east of Woodville Highway. Access to areas south of Bloxham Cutoff and east of the Wakulla River will be impossible.
- 9.1 - Catastrophic flooding south of US-98 between the Wakulla and St Marks Rivers. Riverside portions of St. Marks will be under 7 feet of water with most of the town flooded up to 5 feet of water. Portions of the town of St Marks will be under water up to 7 feet deep. US-98 will flood in numerous spots between the Wakulla and St Marks Rivers restricting access by motor vehicle.
- 7.1 - Access to Purdom Power Plant becomes restricted above this level. Portions of the plant are prone to flooding at this level. On the west bank of the St Marks River above the town of St Marks, homes not elevated will flood at this level as far as 2 miles north of US-98.
Gauge Info
| Coordinates | 30.1506, -84.2106 |
| RFC | SERFC |
| State | FL |
| WFO | TAE |
| County | Wakulla |
| Data Provider(s) | |
| NWFWMD | Northwest Florida Water Management District |
Gauge Location
Recent Crests
| 1. | 2.02 ft | on 09-16-2020 |
| 2. | 8.01 ft | on 10-10-2018 |
| 3. | 2.89 ft | on 05-28-2018 |
| 4. | 2.73 ft | on 10-08-2017 |
| 5. | 1.56 ft | on 01-22-2017 |
Recent Crests
| 1. | 2.02 ft | on 09-16-2020 |
| 2. | 8.01 ft | on 10-10-2018 |
| 3. | 2.89 ft | on 05-28-2018 |
| 4. | 2.73 ft | on 10-08-2017 |
| 5. | 1.56 ft | on 01-22-2017 |
| 6. | 5.08 ft | on 09-02-2016 |
| 7. | 2.72 ft | on 06-06-2016 |
| 8. | 1.90 ft | on 06-06-2016 |
| 9. | 2.33 ft | on 02-24-2016 |
| 10. | 1.92 ft | on 01-15-2016 |
| 11. | 2.06 ft | on 10-27-2015 |
Historic Crests
| 1. | 8.01 ft | on 10-10-2018 |
| 2. | 5.08 ft | on 09-02-2016 |
| 3. | 2.89 ft | on 05-28-2018 |
| 4. | 2.73 ft | on 10-08-2017 |
| 5. | 2.72 ft | on 06-06-2016 |
Historic Crests
| 1. | 8.01 ft | on 10-10-2018 |
| 2. | 5.08 ft | on 09-02-2016 |
| 3. | 2.89 ft | on 05-28-2018 |
| 4. | 2.73 ft | on 10-08-2017 |
| 5. | 2.72 ft | on 06-06-2016 |
| 6. | 2.33 ft | on 02-24-2016 |
| 7. | 2.06 ft | on 10-27-2015 |
| 8. | 2.02 ft | on 09-16-2020 |
| 9. | 1.92 ft | on 01-15-2016 |
| 10. | 1.90 ft | on 06-06-2016 |
| 11. | 1.56 ft | on 01-22-2017 |
Probability Information
No Images Available
Collaborative Agencies
The National Weather Service prepares its forecasts and other services in collaboration with agencies like the US Geological Survey, US Bureau of Reclamation, US Army Corps of Engineers, Natural Resource Conservation Service, National Park Service, ALERT Users Group, Bureau of Indian Affairs, and many state and local emergency managers across the country. For details, please click here.
