Potomac River Information
Nice/Middleton Bridge Status
The Nice/Middleton Bridge Project is the home page for construction status and waterway restrictions during construction. Photos and video feed of construction are also available. Check this site before going up river until construction completes.
Tides matter on the water, low water presents problems entering some creeks off the river due to sand bars across the entrances. Below are tide tables for Dahlgren and tide offsets up and down the river to allow estimation of tide at other locations.
Tide times below should be accurate, Tide heights can be off significantly due to local conditions that are not modeled. If accurate tide height is needed it is recommended that you check the NOAA tide station in Dahlgren for the current tide height to determine the current tide height offset to apply to the table height. The NOAA chart shows a graph with the calculated and actual tide heights in Dahlgren.
- Strong multi-day north winds will blow significant water down river resulting in lower tide heights sometimes 1 to 1.5 foot difference.
- Strong multi-day south/southeast winds will blow significant water upriver resulting in higher tide heights sometimes 1 to 1.5 foot difference.
- Potomac River flow rate can have a mild effect on tide heights.
- Dahlgren - Upper Machodoc Creek Tides - 2023
- NOAA Tide & River Conditions at Dahlgren
- Tidal Differences and Other Constants
- Wind Conditions at Baber Point Light at mouth of Upper Machodoc Creek at Dahlgren
- NOAA Wind Forecast for Chesapeake Bay
- NOAA Chesapeake Bay Buoy Data Access
Potomac Weapon Range
NSWC Dahlgren operates a weapons range from the 301 Bridge south on the Potomac River occupying most of the river width. The range is marked on the river with yellow buoys. Part or all of the range may be closed on any part of any day. During closure all boating activity in the closed section is prohibited. If you are in the vicinity during closure check with the range boat for clearance to transit the range. Transit might be possible between test shots depending upon range activities and transit time but only following authorization from the range. Check the following link for the current schedule of operations and contact information.
Everyone needs charts
- NOAA Office of Coast Survey Downloadable PDF Charts
- National Geospatial Agency US Notice to Mariners
Water quality is important if you are on the water and in contact with it. Even if you are not swimming, water spray will get on you, and the bottom silt when you pull up an anchor. The following links are a starting point.
- USGS Water Science for Maryland, Delaware and the District of Colombia
- USGS Water Science for Virginia
- Virginia Department of Health Shellfish Sanitation
- NCCOS Vibrio Vulnificus forecast (Flesh Eating Bacteria)
USCG Notice to Mariners
USGC Local Notice To Mariners Atlantic Area Region 5 includes notices for PA, NJ, DE, MD, VA, NC
Report problem with USGC Aid to Navigation
If you observe a problem with a USCG buoy, day mark or light it should be reported to get repaired. DYC has prepared guidance in how to submit the USCG online form.
Hurricane and other storm history
High water and waves impact DYC facilities. The links below provide additional information on hurricanes that have passed through the area and the recent high tide event.
- Baltimore-Washington Hurricane History 1878-2012
- Hurricane Isabel in 2003 had the greatest impact on the DYC facilities. The main pier was destroyed requiring complete replacement. Water was just over the toilet bowels in the new Dockhouse and required extensive cleaning, drying out and sanitization of the building. Tide height is not available from the NOAA tide station 8635027 located on the Dahlgren Naval Base as records are available only back to October 2015. Max height for the 28-29 Oct 2021 tides were 5.64' giving an estimated Isabel water height of 7.3'.
- The high tides driven by a high pressure to the north and a low pressure to the south in the Atlantic on 28-29 October 2021 also did significant damage to the pier along the ramp. The parking lot was under water but the building just stayed dry. The tide heights are shown in this chart of the event with a maximum height of 5.64' at 11:18 EDT on 29 October 2021.