As an integrated part of the WSC, the Surface Water Team monitors and conducts investigative research to describe and improve our region's understanding of extreme hydrologic events - droughts, floods and flood hazards, and coastal or bay storm surge and inundation. They also facilitate measurement of precipitation, streamflow, stage and computation of streamflow at locations in Maryland, Delaware, and the District of Columbia. Surface Water also conducts surface water-quality monitoring in our Hydrologic Networks to help meet many partner needs.
Guided by the Assistant Director for Data, the Surface Water Team utilizes a multidisciplinary approach in operating our Hydrologic Networks to meet the data-collection goals that support the needs of local and Regional partners and policy-makers, as well as the research interests of our academic partners and the USGS. This approach includes a broad knowledge of basin characteristics, stream geomorphology and hydrology, and coastal hydrology. This knowledge is combined with advanced statistical analysis and data-collection techniques in streamflow gaging, water-quality monitoring, and quality-assurance.
USGS Studies Low-Flow Changes in the Delaware River Basin
Low flows measured during 1980-2018 increased along with increased precipitation, although low flows decreased in the Coastal Plain area, in the southern part of the basin, where water use and impervious surface have increased.
Zero or not? Causes and consequences of zero-flow stream gage reading
Efforts to restore water quality in Chesapeake Bay and its tributaries often include extensive Best Management Practice (BMP) implementation on agricultural and developed lands, accounting for reductions of nitrogen loads, phosphorus, and sediment.
Spatial, Temporal Patterns of BMPs in the Chesapeake Bay Watershed
Efforts to restore water quality in Chesapeake Bay and its tributaries often include extensive Best Management Practice implementation on agricultural and developed lands. These include a variety of methods to reduce nutrient and sediment loads.
Surface Water Capabilities Highlights
As a Federal agency, the USGS provides water information that is fundamental to national and local economic well-being, protection of life and property, and effective management of the Nation’s water resources. Below, find data and tools relevant to a wide range of water resources and conditions including streamflow, groundwater, water quality, and water use and availability.
The USGS partners with many cooperators to build an infrastructure of state-of-the-art data collection, data processing, and data management tools providing an invaluable resources for analyses, mapping, modeling, and research. Below are a few of the tools that keeps cooperators coming back to parter with us.
NWIS WEB
The USGS's National Water Information System (NWIS) is a comprehensive and distributed application that supports the acquisition, processing, and long-term storage of water data. Water Data for the Nation serves as the publicly available portal to a geographically seamless set of much of the water data maintained within NWIS. For Maryland, Delaware, and the District of Columbia, the online National Water Informations System (NWIS WEB) serves...
Real-Time Data: 224 sites in Maryland, 58 in Delaware, and 13 in the District of Columbia
Historical Observations: 306 sites in Maryland, 86 in Delaware, and 14 in the District of Columbia
Daily Data: 391 sites in Maryland, 95 in Delaware, and 17 in the District of Columbia
Statistics (Daily/Monthly/Annual): 354 sites in Maryland, 75 in Delaware, and 11 in the District of Columbia
Peak-Flow Data: 279 sites in Maryland, 68 in Delaware, and 4 in the District of Columbia
Field Measurements: 608 sites in Maryland, 100 in Delaware, and 8 in the District of Columbia
Mobile Water Data
The new USGS Mobile Water Data site (m.waterdata.usgs.gov) is a site designed for mobile users. It highlights USGS current conditions water data. For example, you can use it to monitor conditions at a favorite river or stream. Any USGS current conditions water data is available. Simply use any browser to go to m.waterdata.usgs.gov. While the site was designed for smartphones, it may work fine on tablet computers, most other mobile devices and desktop computers.
StreamStats
StreamStats provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, get basin characteristics and estimates of flow statistics, and more. Available information varies from state to state. StreamStats works within Web browser software on personal computers and mobile devices, and is best viewed using the latest versions of Internet Explorer, Microsoft Edge, Chrome, Opera or Firefox.
Flood Innundation Mapper
USGS Flood Inundation Maps, along with Internet information regarding current stage from the USGS streamgage, provide emergency management personnel and residents with information that is critical for flood-response activities, such as evacuations and road closures, as well as for post-flood recovery efforts. The Flood Innundation Mapper is a Web application that allows users to explore the full set of inundation maps that shows where flooding would occur given a selected stream condition. Users can also access historical flood information and potential loss estimates based on the severity of the flood. The Flood Innundation Mapper works within Web browser software on personal computers and mobile devices, and is best viewed using the latest versions of Internet Explorer, Microsoft Edge, Chrome, Opera or Firefox.
PeakFQ
Program PeakFQ implements the Bulletin 17C procedures for flood-frequency analysis of streamflow records, providing estimates of flood magnitudes and their corresponding variance for a range of annual exceedance probabilities. The output also includes estimates of the parameters of the log-Pearson Type III frequency distribution, including the logarithmic mean, standard deviation, skew, and mean square error of the skew. The output graph includes the fitted frequency curve, systematic peaks, low outliers, censored peaks, interval peaks, historic peaks, thresholds, and confidence limits.
PeakFQ reads annual peaks in the standard peakfq (WATSTORE) text format available from NWISWeb at https://nwis.waterdata.usgs.gov/usa/nwis/peak
Below are projects and science features focusing on our Surface Water capabilities.
Coastal Monitoring Tide Gage Sites in Maryland, Delaware, and Washington, D.C.
A Handbook for Resource Managers to Understand and Utilize Sea-Level Rise and Coastal Wetland Models
News features that are related to Surface Water sciences typically have to due with environmental extremes that cause loss of life or loss of property. Floods and droughts are typical news features that name the USGS water resources as a go-to resource. For all news items, please see below...
Maryland Storm-Tide Sensor Network Strengthened
Vital coastal storm-tide information needed to help guide storm response efforts following major storms affecting Maryland will be more accessible than ever due to a new monitoring network the U.S. Geological Survey is currently building.
Below are FAQs relating to Surface Water. Since the topic of Surface Water is so broad, we're providing this link to the main USGS Surface Water FAQ that resides under the main USGS Water Resources site.
Where can I find detailed sampling methods for surface water and groundwater?
The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for USGS personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. The manual is published as separate chapters. Learn more: Techniques of Water-Resources Investigations Reports
What does the term "stream stage" mean?
Stream stage is an important concept when analyzing how much water is moving in a stream at any given moment. "Stage" is the water level above some arbitrary point in the river and is commonly measured in feet. For example, on a normal day when no rain has fallen for a while, a river might have a stage of 2 feet. If a big storm hits, the river stage could rise to 15 or 20 feet, sometimes very...
How often are real-time streamflow data updated?
USGS real-time streamflow data are typically recorded at 15-minute intervals, stored onsite, and then transmitted to USGS offices once every hour, depending on the data relay technique used. Recording and transmission times might be more frequent during critical events (floods, for example). Data from current sites are relayed to USGS offices via satellite, telephone, and/or radio telemetry and...
What is a digital elevation model (DEM)?
A Digital Elevation Model (DEM) is a representation of the bare ground (bare earth) topographic surface of the Earth excluding trees, buildings, and any other surface objects. DEMs are created from a variety of sources. USGS DEMs used to be derived primarily from topographic maps. Those are being systematically replaced with DEMs derived from high-resolution lidar and IfSAR (Alaska only) data...
What are the long-term effects of climate change?
Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...
How are floods predicted?
Flood predictions require several types of data: The amount of rainfall occurring on a real-time basis. The rate of change in river stage on a real-time basis, which can help indicate the severity and immediacy of the threat. Knowledge about the type of storm producing the moisture, such as duration, intensity and areal extent, which can be valuable for determining possible severity of the...
Where can I get real-time and historical streamflow information?
The best starting point for USGS streamflow data is the interactive National Water Information System (NWIS): Mapper website. Zoom in to your area of interest or use the search options in the left navigation window. The map displays active surface-water sites by default, but you can change the type of water site (surface-water, groundwater, springs, atmospheric) and select to show inactive sites...
Does an increase in the 100-year flood estimate originate from climate or land-use change?
Climate variability (dry cycles to wet cycles) and land-use change play a significant role, but there is a large amount of uncertainty around the flood quantile estimates (the value of discharge corresponding to the 100-year flood), particularly if there isn’t a long record of observed data at a stream location. Learn more: The 100-Year Flood The 100-Year Flood--It's All About Chance
How can I obtain river forecasts (flood forecasts)?
River forecasts (flood forecasts) are made by the National Weather Service River Forecast Centers and released through local Weather Service Offices. This NOAA website has a map showing the location of the forecast centers, their areas of responsibility, and by clicking into a region the location of the gages they use. The also provide a section for long-range river flood risk. The vast majority...
- Overview
As an integrated part of the WSC, the Surface Water Team monitors and conducts investigative research to describe and improve our region's understanding of extreme hydrologic events - droughts, floods and flood hazards, and coastal or bay storm surge and inundation. They also facilitate measurement of precipitation, streamflow, stage and computation of streamflow at locations in Maryland, Delaware, and the District of Columbia. Surface Water also conducts surface water-quality monitoring in our Hydrologic Networks to help meet many partner needs.
Guided by the Assistant Director for Data, the Surface Water Team utilizes a multidisciplinary approach in operating our Hydrologic Networks to meet the data-collection goals that support the needs of local and Regional partners and policy-makers, as well as the research interests of our academic partners and the USGS. This approach includes a broad knowledge of basin characteristics, stream geomorphology and hydrology, and coastal hydrology. This knowledge is combined with advanced statistical analysis and data-collection techniques in streamflow gaging, water-quality monitoring, and quality-assurance.
USGS Studies Low-Flow Changes in the Delaware River Basin
Low flows measured during 1980-2018 increased along with increased precipitation, although low flows decreased in the Coastal Plain area, in the southern part of the basin, where water use and impervious surface have increased.
Zero or not? Causes and consequences of zero-flow stream gage reading
Efforts to restore water quality in Chesapeake Bay and its tributaries often include extensive Best Management Practice (BMP) implementation on agricultural and developed lands, accounting for reductions of nitrogen loads, phosphorus, and sediment.
Spatial, Temporal Patterns of BMPs in the Chesapeake Bay Watershed
Efforts to restore water quality in Chesapeake Bay and its tributaries often include extensive Best Management Practice implementation on agricultural and developed lands. These include a variety of methods to reduce nutrient and sediment loads.
Surface Water Capabilities Highlights
As a Federal agency, the USGS provides water information that is fundamental to national and local economic well-being, protection of life and property, and effective management of the Nation’s water resources. Below, find data and tools relevant to a wide range of water resources and conditions including streamflow, groundwater, water quality, and water use and availability.
The USGS partners with many cooperators to build an infrastructure of state-of-the-art data collection, data processing, and data management tools providing an invaluable resources for analyses, mapping, modeling, and research. Below are a few of the tools that keeps cooperators coming back to parter with us.
NWIS WEB
The USGS's National Water Information System (NWIS) is a comprehensive and distributed application that supports the acquisition, processing, and long-term storage of water data. Water Data for the Nation serves as the publicly available portal to a geographically seamless set of much of the water data maintained within NWIS. For Maryland, Delaware, and the District of Columbia, the online National Water Informations System (NWIS WEB) serves...
Real-Time Data: 224 sites in Maryland, 58 in Delaware, and 13 in the District of Columbia
Historical Observations: 306 sites in Maryland, 86 in Delaware, and 14 in the District of Columbia
Daily Data: 391 sites in Maryland, 95 in Delaware, and 17 in the District of Columbia
Statistics (Daily/Monthly/Annual): 354 sites in Maryland, 75 in Delaware, and 11 in the District of Columbia
Peak-Flow Data: 279 sites in Maryland, 68 in Delaware, and 4 in the District of Columbia
Field Measurements: 608 sites in Maryland, 100 in Delaware, and 8 in the District of Columbia
Mobile Water Data
The new USGS Mobile Water Data site (m.waterdata.usgs.gov) is a site designed for mobile users. It highlights USGS current conditions water data. For example, you can use it to monitor conditions at a favorite river or stream. Any USGS current conditions water data is available. Simply use any browser to go to m.waterdata.usgs.gov. While the site was designed for smartphones, it may work fine on tablet computers, most other mobile devices and desktop computers.
StreamStats
StreamStats provides access to spatial analytical tools that are useful for water-resources planning and management, and for engineering and design purposes. The map-based user interface can be used to delineate drainage areas, get basin characteristics and estimates of flow statistics, and more. Available information varies from state to state. StreamStats works within Web browser software on personal computers and mobile devices, and is best viewed using the latest versions of Internet Explorer, Microsoft Edge, Chrome, Opera or Firefox.
Flood Innundation Mapper
USGS Flood Inundation Maps, along with Internet information regarding current stage from the USGS streamgage, provide emergency management personnel and residents with information that is critical for flood-response activities, such as evacuations and road closures, as well as for post-flood recovery efforts. The Flood Innundation Mapper is a Web application that allows users to explore the full set of inundation maps that shows where flooding would occur given a selected stream condition. Users can also access historical flood information and potential loss estimates based on the severity of the flood. The Flood Innundation Mapper works within Web browser software on personal computers and mobile devices, and is best viewed using the latest versions of Internet Explorer, Microsoft Edge, Chrome, Opera or Firefox.
PeakFQ
Program PeakFQ implements the Bulletin 17C procedures for flood-frequency analysis of streamflow records, providing estimates of flood magnitudes and their corresponding variance for a range of annual exceedance probabilities. The output also includes estimates of the parameters of the log-Pearson Type III frequency distribution, including the logarithmic mean, standard deviation, skew, and mean square error of the skew. The output graph includes the fitted frequency curve, systematic peaks, low outliers, censored peaks, interval peaks, historic peaks, thresholds, and confidence limits.
PeakFQ reads annual peaks in the standard peakfq (WATSTORE) text format available from NWISWeb at https://nwis.waterdata.usgs.gov/usa/nwis/peak
- Science
Below are projects and science features focusing on our Surface Water capabilities.
Coastal Monitoring Tide Gage Sites in Maryland, Delaware, and Washington, D.C.
Vital coastal storm-tide information needed to help guide storm response efforts following major storms affecting Maryland will be more accessible than ever due to a new monitoring network the U.S. Geological Survey is currently building. A team from the USGS MD-DE-DC Water Science Center is surveying 63 locations in the state, determining their elevations and installing receiving brackets at...A Handbook for Resource Managers to Understand and Utilize Sea-Level Rise and Coastal Wetland Models
Coastal wetlands and the many beneficial services they provide (e.g., purifying water, buffering storm surge, providing habitat) are changing and disappearing as a result of sea-level rise brought about by climate change. Scientists have developed a wealth of information and resources to predict and aid decision-making related to sea-level rise. However, while some of these resources are easily ac - Data
- Multimedia
- Publications
- Web Tools
- Software
- News
News features that are related to Surface Water sciences typically have to due with environmental extremes that cause loss of life or loss of property. Floods and droughts are typical news features that name the USGS water resources as a go-to resource. For all news items, please see below...
Maryland Storm-Tide Sensor Network Strengthened
Vital coastal storm-tide information needed to help guide storm response efforts following major storms affecting Maryland will be more accessible than ever due to a new monitoring network the U.S. Geological Survey is currently building.
- FAQ
Below are FAQs relating to Surface Water. Since the topic of Surface Water is so broad, we're providing this link to the main USGS Surface Water FAQ that resides under the main USGS Water Resources site.
Where can I find detailed sampling methods for surface water and groundwater?
The National Field Manual for the Collection of Water-Quality Data (National Field Manual) provides guidelines and standard procedures for USGS personnel who collect data used to assess the quality of the Nation’s surface water and groundwater resources. The manual is published as separate chapters. Learn more: Techniques of Water-Resources Investigations Reports
What does the term "stream stage" mean?
Stream stage is an important concept when analyzing how much water is moving in a stream at any given moment. "Stage" is the water level above some arbitrary point in the river and is commonly measured in feet. For example, on a normal day when no rain has fallen for a while, a river might have a stage of 2 feet. If a big storm hits, the river stage could rise to 15 or 20 feet, sometimes very...
How often are real-time streamflow data updated?
USGS real-time streamflow data are typically recorded at 15-minute intervals, stored onsite, and then transmitted to USGS offices once every hour, depending on the data relay technique used. Recording and transmission times might be more frequent during critical events (floods, for example). Data from current sites are relayed to USGS offices via satellite, telephone, and/or radio telemetry and...
What is a digital elevation model (DEM)?
A Digital Elevation Model (DEM) is a representation of the bare ground (bare earth) topographic surface of the Earth excluding trees, buildings, and any other surface objects. DEMs are created from a variety of sources. USGS DEMs used to be derived primarily from topographic maps. Those are being systematically replaced with DEMs derived from high-resolution lidar and IfSAR (Alaska only) data...
What are the long-term effects of climate change?
Scientists have predicted that long-term effects of climate change will include a decrease in sea ice and an increase in permafrost thawing, an increase in heat waves and heavy precipitation, and decreased water resources in semi-arid regions. Below are some of the regional impacts of global change forecast by the Intergovernmental Panel on Climate Change: North America: Decreasing snowpack in the...
How are floods predicted?
Flood predictions require several types of data: The amount of rainfall occurring on a real-time basis. The rate of change in river stage on a real-time basis, which can help indicate the severity and immediacy of the threat. Knowledge about the type of storm producing the moisture, such as duration, intensity and areal extent, which can be valuable for determining possible severity of the...
Where can I get real-time and historical streamflow information?
The best starting point for USGS streamflow data is the interactive National Water Information System (NWIS): Mapper website. Zoom in to your area of interest or use the search options in the left navigation window. The map displays active surface-water sites by default, but you can change the type of water site (surface-water, groundwater, springs, atmospheric) and select to show inactive sites...
Does an increase in the 100-year flood estimate originate from climate or land-use change?
Climate variability (dry cycles to wet cycles) and land-use change play a significant role, but there is a large amount of uncertainty around the flood quantile estimates (the value of discharge corresponding to the 100-year flood), particularly if there isn’t a long record of observed data at a stream location. Learn more: The 100-Year Flood The 100-Year Flood--It's All About Chance
How can I obtain river forecasts (flood forecasts)?
River forecasts (flood forecasts) are made by the National Weather Service River Forecast Centers and released through local Weather Service Offices. This NOAA website has a map showing the location of the forecast centers, their areas of responsibility, and by clicking into a region the location of the gages they use. The also provide a section for long-range river flood risk. The vast majority...
- Partners