Web Portal Changes: The Advanced Hydrologic Prediction Service (AHPS) hosted at https://water.weather.gov will be replaced by the National Water Prediction Service (NWPS), with a target of March 2024. Existing AHPS content and features will be preserved and expanded within NWPS.

Experimental National Water Center Products: Flood Inundation Mapping services are now available for 10% of the U.S. population. Please visit https://www.weather.gov/owp/operations for more information. The National Hydrologic Discussion, Area Hydrologic Discussion, Flood Hazard Outlook, and real-time geospatial services depicting River Forecast Center and National Water Model forecasts, continue to be accessible via the URL above, as described in the StoryMap here.

Weather Forecast Office Philadelphia/Mount Holly, NJ

Middle Atlantic River Forecast Center

Hydrograph

River at a Glance

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Printable Image About this graph Tabular Data (UTC) Tabular Data (EDT) Datum: Not Available Metadata

NOTE: Forecasts are not available for the Tulpehocken Creek at Blue Marsh Dam. Only observed stages are available for this point.

Default Hydrograph Scale to Flood Categories   Return to Area Map

Downstream Gauge

Flood Categories (in feet) Major Flood Stage: 0 Moderate Flood Stage: 0 Flood Stage: 0 Action Stage: 307 Low Stage (in feet): -9999 Historic Crests (1) 309.39 ft on 09/09/2011 (2) 309.19 ft on 06/28/2006 (P): Preliminary values subject to further review. Recent Crests (1) 309.39 ft on 09/09/2011 (2) 309.19 ft on 06/28/2006 (P): Preliminary values subject to further review. Low Water Records Currently none available. For more information on your flood risk go to www.floodsmart.gov. Show FEMA's National Flood Hazard Layers FEMA's National Flood Hazard Layers not showing? Why aren't the FEMA National Flood Hazard Layers showing on the ESRI Map? Possible reasons: There are no FEMA National Flood Hazard Layers for the location which you are viewing on ESRI Maps. The FEMA Web Mapping Service (WMS) is down. Note: Your zoom level may have changed. ESRI's zoom levels must be between 14 and 16 to show National Flood Hazard layers.

Zoom Level:16 Legend FEMA Layer Gauge Location Disclaimer Latitude/Longitude Disclaimer: The gauge location shown in the above map is the approximate location based on the latitude/longitude coordinates provided to the NWS by the gauge owner.

Flood Impacts & Photos

If you notice any errors in the below information, please contact our Webmaster
309	Rebers Bridge Road is subject to closures.
307	The level at which the reservoir begins to spill. A spillway is located at the top of the reservoir pool. It's a structure used to provide a controlled release of water when reservoirs are at or near capacity. Spilling can occur for weeks or months and does not cause flooding below the dam.
303	Route 183 floods between Mt. Pleasant and Bernville.
295	The beach at the Dry Brooks Day Use Center is subject to closure.
292	Boat launch ramps around the lake are subject to closure.
Photos (1) Blue Marsh Dam & Gage

About This Location

Latitude: 40.379167° N, Longitude: 76.033056° W, Horizontal Datum: NAD83/WGS84 River Stage Reference Frame Gauge Height Flood Stage Uses NWS stage 0 ft Not Available 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 Not Available Not Available Survey grade GPS equipment, FEMA flood plain maps, newer USGS topographic maps NGVD 29 Not Available Not Available Older USGS topographic maps, NGVD29 benchmarks MSL Not Available Not Available Older USGS topographic maps, MSL benchmarks Other 0 ft 307 ft

Additional Information

During winter months, cold and ice may result in inaccurate real-time stream stage and streamflow data. Adjustments or deletions of this data can only be done after detailed analysis.

Resources

Hydrologic Resources Text Products Past Precipitation Forecast Precipitation River Forecast Centers River Stage Summary Inundation Mapping Locations

Additional Resources Area Hydrographs NWS Precipitation and River Forecasting AHPS Iframes for Developers Mobile iNWS for emergency management Snow Information Ensemble River Forecasts Hourly Precipitation

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. NWS Information National Weather Service Philadelphia/Mount Holly Weather Forecast Office 732 Woodlane Road Mount Holly, NJ 08060-9615 (609) 261-6600 Ask Questions/Webmaster Page last modified: 2-Nov-2020 7:30 PM Disclaimer Credits Glossary Privacy Policy About Us Career Opportunities