Water Resources of Pennsylvania
The Conowingo Dam on the Susquehanna River is at about 92 percent capacity for sediment storage.
Since the dam’s construction in 1929, sediment and nutrients have been building up behind it, being released periodically downriver and into the Chesapeake Bay, especially during high flow events. As the reservoir nears full capacity it has begun to lose its phosphorus and sediment-trapping ability, with increasing amounts going into the Bay.
- Estimate baseline streamflow (minimally altered by regulation, diversion, or mining, and other anthropogenic activities) for ungaged streams in Pennsylvania
- Generate text file of daily mean streamflow for the ungaged site for the period 1960 to 2008
- Create a report that includes streamflow data, exceedance probabilities, basin characteristics, and hydrographs for the ungaged site
Flood Inundation Mapper
View maps of current and historic flood inundation
Baseline Streamflow Estimator (BaSE)
Estimate baseline streamflow for ungaged streams in Pennsylvania
Delineate watersheds and estimate streamflow
- NWIS Mapper
View the locations of sites with USGS water data
Compare current streamflow to historical record
View stream-temperature and water-quality monitoring data
- Groundwater Watch
Compare current groundwater levels to historical record
- Groundwater Recharge
Compare aquifer recharge for 197 watersheds
Get condition updates by text message or email
The USGS Pennsylvania Water Science Center is your direct link to all kinds of water-resource information. Data collection and interpretive studies are done in cooperation with various local, State, and Federal agencies.
Streamflow, lake, reservoir, and precipitation data
Water levels in wells and other aquifer data
Chemical and biological quality data for surface water and groundwater
- New map tool shows when Susquehanna River will flood in your neighborhood
- Acid Rain Effects on Forest Soils begin to Reverse (Wed, 4 Nov 2015 10:00:00 EDT)
- Grass Carp Eggs Compromised by Settling on Streambeds (Thu, 15 Oct 2015 14:10:33 EDT)
- Atlantic Beaches Still Likely to be Affected by Hurricane Joaquin (Fri, 2 Oct 2015 18:16:08 EDT)
- Interior's Northeast Climate Science Center Releases Report to Help State Wildlife Managers in the Northeast and Midwest Alleviate Impacts of Climate Change on Species and Ecosystems (Mon, 29 Jun 2015 9:00:00 EDT)
- Asian Carp Would Have Adequate Food to Survive in Lake Erie (Wed, 6 May 2015 9:15:00 EDT)
On-demand, current conditions for water data directly to your mobile phone or email. 2 ways to get started:
- Send a text message to WaterNow@usgs.gov containing the USGS Site Number of the gage you want to query
- Send an email message to WaterNow@usgs.gov where either the Subject or the first line of the message contains the USGS Site Number of the gage you want to query
Just What Is a 100-Year Flood Anyway?
Almost everyone has heard the term "100-year flood", but not everyone knows what it really means. A common question is, "we just had a 100-year flood a few years ago, why are we having another one so soon?" The USGS Office of Surface Water has released a poster that explains the concept, probabilistic nature, and inherent uncertainties of a 100-year flood. The poster, entitled "100-Year Flood—It's All About Chance," can be found at http://pubs.usgs.gov/gip/106/.