Latitude: 38.873333° N,
Longitude: 77.021111° W,
Horizontal Datum:
NAD83
River Stage
Reference Frame |
Gauge Height |
Flood Stage |
Uses |
| NWS stage |
0 ft |
4.2 ft |
Interpreting hydrographs and NWS watch, warnings, and forecasts, and inundation maps |
| Vertical Datum |
Elevation
(gauge height = 0) |
Elevation
(gauge height = flood stage) |
Elevation information source |
| NAVD88 |
-1.40 |
2.8 |
Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps |
| NGVD 29 |
-0.62 |
3.58 |
Older USGS topographic maps, NGVD29 benchmarks |
| MSL |
-1.55 |
2.65 |
Older USGS topographic maps, MSL benchmarks |
| Other |
Not Available |
4.2 |
MLLW (Mean Lower Low Water) |
|