Delaware River at Marcus Hook (IN MLLW)
Pennsylvania — Water Level & Flood Stage
Located in Philadelphia County, Pennsylvania on the Delaware River. Live water level data from USGS, updated every 15 minutes.
Current Water Level
Gage Height
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Streamflow
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Last Reading
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This is an NWS forecast point (LID: MRCP1). Live data may be limited. View on NWS AHPS →
Flood Stages
Major Flood
9.7 ft
Moderate Flood
8.7 ft
Minor Flood
7.7 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
10.14 ft
(Mean Lower Low Water (MLLW)) The level reached on October 30, 2012 during Post Tropical Cyclone Sandy.
9.76 ft
(MLLW) The level reached on April 16, 2011.
9.75 ft
(MLLW) The level reached on December 21, 2012.
9.72 ft
(MLLW) The level reached on October 29, 2021.
9.7 ft
(MLLW) MAJOR FLOODING. At this level, widespread roadway flooding begins near the river and its tidal tributaries in Delaware County, Pennsylvania and Gloucester County, New Jersey. Vulnerable homes and businesses may be damaged as water levels rise further above this threshold. Numerous roads become impassable and some neighborhoods may be isolated. The flood waters become a danger to anyone who attempts to cross on foot or in a vehicle.
8.7 ft
(MLLW) MODERATE FLOODING. At this level, additional roadways near the river and its tidal tributaries in Delaware County, Pennsylvania and Gloucester County, New Jersey begin to flood. Lives may be at risk when people put themselves in harm's way. Some damage to vulnerable structures may begin to occur. COASTAL FLOOD WARNING LEVEL.
8.5 ft
(MLLW) Flooding begins in Tinicum Township PA between Philadelphia International Airport and Essington, and along the lower Darby Creek.
8.3 ft
(MLLW) Flooding begins along the Nehonsey Brook in Gibbstown (Greenwich Township) NJ at South Poplar Street and Democrat Road.
8.1 ft
(MLLW) Flooding begins along Mantua Creek in Gloucester County NJ. Flooding begins along Island Road, High Hill Road, Center Square Road and Pedricktown Road in Logan Township NJ. Flooding begins along US 130 at Oldmans Creek.
8 ft
(MLLW) COASTAL FLOOD ADVISORY LEVEL.
7.9 ft
(MLLW) The Repaupo Creek overflows onto Flood Gates Road in Greenwich Township and Logan Township NJ.
7.7 ft
(MLLW) MINOR FLOODING.
Impact statements from the National Weather Service, describing what typically happens at each water level.
7-Day Water Level Chart
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Historic Crests
| Date | Stage | Flow |
|---|---|---|
| Oct 29, 2012 | 10.14 ft | — |
| Oct 29, 2012 | 10.14 ft | — |
| Apr 15, 2011 | 9.76 ft | — |
| Apr 15, 2011 | 9.76 ft | — |
| Dec 20, 2012 | 9.75 ft | — |
About This Gauge
NWS LID
MRCP1
River
Delaware River
County
Philadelphia, PA
Coordinates
39.8117°N, 75.4100°W
Get Flood Alerts for Delaware River
StormCast monitors this gauge and sends a push notification to your phone when the water level crosses into a new flood category — even at 3 AM.
Frequently Asked Questions
What is the current water level of Delaware River at Marcus Hook (IN MLLW)?
The Delaware River at Marcus Hook (IN MLLW) gauge is maintained by USGS and reports water levels every 15 minutes. Visit this page to see the latest reading updated live, or download StormCast to get push alerts when levels rise.
What is flood stage for Delaware River at Marcus Hook (IN MLLW)?
The NWS-defined flood stage for Delaware River at Marcus Hook (IN MLLW) is 7.7 feet. Action stage begins at N/A feet. Moderate flooding starts at 8.7 feet, and major flooding at 9.7 feet.
How do I get alerts when Delaware River rises?
Download StormCast free on Google Play, go to River Gauges, and add Delaware River at Marcus Hook (IN MLLW) to your watchlist. StormCast will send a push notification to your phone whenever the water level crosses into a new NWS flood category — even when your screen is off.
Where is the Delaware River at Marcus Hook (IN MLLW) gauge located?
The gauge is located in Philadelphia County, Pennsylvania at coordinates 39.8117°N, 75.4100°W. Data is provided by the U.S. Geological Survey and the National Weather Service.
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Source & Notes
Data provided by: NOAA National Ocean Service
- <style type="text/css"> .style1 {background-color: #FFFF00;}</style>Please refer to our <style type="text/css"> .style1 { background-color: #FFFF00;} .style2 {background-color: #FFFF00;} </style> <a href="http://forecast.weather.gov/product.php?site=NWS&issuedby=PHI&product=CFW&format=CI&version=1&glossary=0"> <span class="style1">Coastal Hazard Message</span></a> for specific information regarding Coastal Flood Watches, Warnings and Advisories. During tropical cyclones, please refer<a href="https://forecast.weather.gov/product.php?site=NWS&issuedby=PHI&product=TCV&format=CI&version=1&glossary=1"> <span class="style2">here</span></a> for additional storm surge information.
- Flood impacts are based on long-term averages. Actual impacts from any tidal flooding event may vary due to factors such as rainfall, wave action, and the number of tide cycles during which there is an onshore flow.