Pamela Lombard is a Supervisory Hydrologist in the New England Water Science Center.
She currently works on surface water hydrology issues such as streamflow statistics, hydraulic modeling, flood documentation and mapping, water availability/wateruse, and drought, and leads the hydraulic modeling team at the center.
Professional Experience
2021 - present. U.S. Geological Survey - Supervisory Hydrologist
1999 - 2021. U.S. Geological Survey - Hydrologist
Education and Certifications
M.S., Hydrology, Oregon State University (1997)
B.S., Dartmouth College (1990)
Science and Products
Flood Documentation and Inundation Mapping of the January and March 2018 Nor’easters in Coastal Massachusetts
2018 Nor’easters in Coastal Massachusetts
Applied Hydrology Program
The mission of the Applied Hydrology Program of the U.S. Geological Survey (USGS) New England Water Science Center (WSC) is to support water resource managers, stakeholders, and policy makers with the hydrologic data, interpretation, and tools they need to manage and make critical decisions about water resources throughout New England. This program is divided into two broad sections: the Hydrology...
Development of Flood Insurance Maps in New England
FEMA has requested USGS expertise in hydraulics, hydrology, and mapping to generate flood insurance maps for New England.
Development of Regional Regression Equations to Estimate the Magnitude of Peak Flows for Selected Annual-Exceedance Probabilities in Maine
The flood-frequency characteristics for streamgages and regression equations for estimating flood magnitudes have been published.
Spatial Coverage for Estimated Baseflow for Streams Containing Endangered Atlantic Salmon in Maine, USA
The U.S. Geological Survey (USGS) developed a regression model for estimating mean August baseflow per square mile of drainage area in cooperation with National Oceanic and Atmospheric Administration (NOAA) to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat (Lombard and others, 2021). The model was applied to each reach of a stream network d
Data and shapefiles used to document the floods associated with the January and March 2018 Nor'easters for Coastal Areas of New England
The U.S. Geological Survey (USGS) New England Water Science Center worked with the Federal Emergency Management Agency to document the floods of January 4, 2018 and March 2-4, 2018, in coastal Massachusetts. USGS conducted a frequency analysis of stillwater elevations at three National Oceanic and Atmospheric Administration coastal gages following the coastal floods of 2018. The data for these an
Results of peak-flow frequency analysis and regionalization for selected streamgages in or near Maine, based on data through water year 2019
The U.S. Geological Survey (USGS) recently completed a report documenting methods for peak-flow frequency analysis following implementation of the Bulletin 17C guidelines (https://doi.org/10.3133/tm4B5). The methods provide estimates of peak-flow quantiles for 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEPs) for selected streamgages operated by the USGS and E
Penobscot River Cross Section Data pre- and post-Dam Removal
The Great Works (20 feet high) and Veazie (30 feet high) dams on the lower section of the Penobscot River in Maine were removed during the summers of 2012 and 2013, respectively. Channel cross sections upstream and downstream of these dams from just below the Milford Dam to the head‐of‐tide at Eddington Bend just below the former Veazie Dam were surveyed before and after the dams were removed in o
Data for Models Estimating Baseflow for Streams Containing Endangered Atlantic Salmon in Maine, USA
The U.S. Geological Survey (USGS) developed a regression model for estimating August mean baseflow per square mile of drainage area to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat. The model was derived from August mean baseflows computed at 31 USGS streamgages in and near the Gulf of Maine Atlantic Salmon Habitat Recovery Units. An ordin
Flood-Inundation Grids and Shapefiles for the Lower Pawcatuck River in Westerly, Rhode Island, and Stonington and North Stonington, Connecticut
A series of 11 digital flood-inundation maps were developed for a 5.5 mile reach of the Pawcatuck River in Westerly, Rhode Island and Stonington and North Stonington, Connecticut by the U.S. Geological Survey in cooperation with the Town of Westerly, Rhode Island and the Rhode Island Office of Housing and Community Development. The coverage of the maps extends from downstream from the Ashaway Rive
Flood Inundation Grids and Shapefiles for the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island
A series of 15 digital flood-inundation shapefiles and grids were developed for a 10.2 mile reach of the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island by the U.S. Geological Survey in cooperation with Rhode Island Emergency Management Agency and U.S. Army Corps of Engineers. The coverage of the maps extends from downstream of Natick Pond Dam near State Route 33/Providence Str
Bathymetric data for St. Croix River at outlet to East Grand Lake and Forest City Dam Survey, United States-Canadian border between Maine and New Brunswick
These are survey data for the Forest City Dam at the Outlet to East Grand Lake on the St. Croix River between Maine and Canada. And they are bathymetric data surrounding the outlet dam collected with an Acoustic Doppler Current Profiler (ADCP)
Precipitation and streamflow data for computing lag to peak at selected stations in Maine
These are rainfall and stream stage data collected at gaging sites in Maine. Data were collected from March to October from 2008 to 2015 and include stage data at crest stage gages, ratings to convert stage data to streamflow data, previously unpublished rainfall data, rainfall binned into specified time intervals, and storm files combining rainfall and streamflow data. Data were collected, compi
Filter Total Items: 30
Documentation and mapping of flooding from the January and March 2018 nor’easters in coastal New England
In January and March 2018, coastal Massachusetts experienced flooding from two separate nor’easters. To put the January and March floods into historical context, the USGS computed statistical stillwater elevations. Stillwater elevations recorded in January 2018 in Boston (9.66 feet relative to the North American Vertical Datum of 1988) have an annual exceedance probability of between 2 and 1 perce
Model estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA
We present a regression model for estimating mean August baseflow per square kilometer of drainage area to help resource managers assess relative amounts of baseflow in Maine streams with Atlantic Salmon habitat. The model was derived from mean August baseflows computed at 31 USGS streamflow gages in Maine. We use an ordinary least squares regression model to estimate mean August baseflow per unit
2020 drought in New England
Below average and infrequent rainfall from May through September 2020 led to an extreme hydrologic drought across much of New England, with some areas experiencing a flash drought, reflecting its quick onset. The U.S. Geological Survey (USGS) recorded record-low streamflow and groundwater levels throughout the region. In September, the U.S. Department of Agriculture (2020) declared Aroostook Count
Estimating flood magnitude and frequency on gaged and ungaged streams in Maine
Accurate estimates of flood frequency and magnitude on rivers and streams in Maine are a key component of effective flood risk management, flood mitigation, and flood recovery programs for the State. Flood-frequency estimates are published here for 148 streamgages in and adjacent to Maine. Equations are provided for users to compute flood-frequency estimates at any location on a stream that does n
River channel response to dam removals on the lower Penobscot River, Maine, United States
Most geomorphology studies of dam removals have focused on sites with appreciable quantities of stored sediments. There is great interest in channel responses to sediment releases because of potential effects on aquatic and riparian habitats and human uses of these areas. Yet, behind many dams in the Northeast U.S. and other regions of the world only minor accumulations of sediment are present bec
A multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA
Factors affecting iron fouling in wet areas adjacent to roadways were investigated by collecting field rock cut and aqueous physicochemical data; developing exploratory predictive models; and developing geochemical models. Basic data included the identification of iron fouling from aerial imagery and field visits at 374 New Hampshire rock cut locations, and their associated rock-fill sites. Based
A multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA
Factors affecting iron fouling in wet areas adjacent to roadways were investigated by collecting field rock cut and aqueous physicochemical data; developing exploratory predictive models; and developing geochemical models. Basic data included the identification of iron fouling from aerial imagery and field visits at 374 New Hampshire rock cut locations, and their associated rock-fill sites. Based
Flood-inundation maps for the lower Pawcatuck River in Westerly, Rhode Island, and Stonington and North Stonington, Connecticut
A series of 11 digital flood-inundation maps was developed for a 5.5-mile reach of the lower Pawcatuck River in Westerly, Rhode Island, and Stonington and North Stonington, Connecticut, by the U.S. Geological Survey (USGS) in cooperation with the Town of Westerly, Rhode Island, and the Rhode Island Office of Housing and Community Development. The coverage of the maps extends from downstream from t
Flood-inundation maps for the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island
A series of 15 digital flood-inundation maps was developed for a 10.2-mile reach of the Pawtuxet River in the municipalities of West Warwick, Warwick, and Cranston, Rhode Island, by the U.S. Geological Survey (USGS), in cooperation with the Rhode Island Emergency Management Agency and the U.S. Army Corps of Engineers. The coverage of the maps extends downstream from Natick Pond dam near State Rout
Estimating lag to peak between rainfall and peak streamflow with a mixed-effects model
We test the use of a mixed-effects model for estimating lag to peak for small basins in Maine (drainage areas from 0.8 to 78 km2). Lag to peak is defined as the time between the center of volume of the excess rainfall during a storm event and the resulting peak streamflow. A mixed-effects model allows for multiple observations at sites without violating model assumptions inherent in traditional or
Estimation of unregulated monthly, annual, and peak streamflows in Forest City Stream and lake levels in East Grand Lake, United States-Canada border between Maine and New Brunswick
The U.S. Geological Survey, in cooperation with the International Joint Commission, compiled historical data on regulated streamflows and lake levels and estimated unregulated streamflows and lake levels on Forest City Stream at Forest City, Maine, and East Grand Lake on the United States-Canada border between Maine and New Brunswick to study the effects on streamflows and lake levels if two or al
Hydrologic and hydraulic analyses of Great Meadow wetland, Acadia National Park, Maine
The U.S. Geological Survey completed hydrologic and hydraulic analyses of Cromwell Brook and the Sieur de Monts tributary in Acadia National Park, Maine, to better understand causes of flooding in complex hydrologic and hydraulic environments, like those in the Great Meadow wetland and Sieur de Monts Spring area. Regional regression equations were used to compute peak flows with from 2 to 100-year
Science and Products
- Science
Flood Documentation and Inundation Mapping of the January and March 2018 Nor’easters in Coastal Massachusetts
2018 Nor’easters in Coastal MassachusettsApplied Hydrology Program
The mission of the Applied Hydrology Program of the U.S. Geological Survey (USGS) New England Water Science Center (WSC) is to support water resource managers, stakeholders, and policy makers with the hydrologic data, interpretation, and tools they need to manage and make critical decisions about water resources throughout New England. This program is divided into two broad sections: the Hydrology...Development of Flood Insurance Maps in New England
FEMA has requested USGS expertise in hydraulics, hydrology, and mapping to generate flood insurance maps for New England.Development of Regional Regression Equations to Estimate the Magnitude of Peak Flows for Selected Annual-Exceedance Probabilities in Maine
The flood-frequency characteristics for streamgages and regression equations for estimating flood magnitudes have been published. - Data
Spatial Coverage for Estimated Baseflow for Streams Containing Endangered Atlantic Salmon in Maine, USA
The U.S. Geological Survey (USGS) developed a regression model for estimating mean August baseflow per square mile of drainage area in cooperation with National Oceanic and Atmospheric Administration (NOAA) to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat (Lombard and others, 2021). The model was applied to each reach of a stream network dData and shapefiles used to document the floods associated with the January and March 2018 Nor'easters for Coastal Areas of New England
The U.S. Geological Survey (USGS) New England Water Science Center worked with the Federal Emergency Management Agency to document the floods of January 4, 2018 and March 2-4, 2018, in coastal Massachusetts. USGS conducted a frequency analysis of stillwater elevations at three National Oceanic and Atmospheric Administration coastal gages following the coastal floods of 2018. The data for these anResults of peak-flow frequency analysis and regionalization for selected streamgages in or near Maine, based on data through water year 2019
The U.S. Geological Survey (USGS) recently completed a report documenting methods for peak-flow frequency analysis following implementation of the Bulletin 17C guidelines (https://doi.org/10.3133/tm4B5). The methods provide estimates of peak-flow quantiles for 50-, 20-, 10-, 4-, 2-, 1-, 0.5-, and 0.2-percent annual exceedance probabilities (AEPs) for selected streamgages operated by the USGS and EPenobscot River Cross Section Data pre- and post-Dam Removal
The Great Works (20 feet high) and Veazie (30 feet high) dams on the lower section of the Penobscot River in Maine were removed during the summers of 2012 and 2013, respectively. Channel cross sections upstream and downstream of these dams from just below the Milford Dam to the head‐of‐tide at Eddington Bend just below the former Veazie Dam were surveyed before and after the dams were removed in oData for Models Estimating Baseflow for Streams Containing Endangered Atlantic Salmon in Maine, USA
The U.S. Geological Survey (USGS) developed a regression model for estimating August mean baseflow per square mile of drainage area to help resource managers assess relative amounts of baseflow in streams with Maine Atlantic Salmon habitat. The model was derived from August mean baseflows computed at 31 USGS streamgages in and near the Gulf of Maine Atlantic Salmon Habitat Recovery Units. An ordinFlood-Inundation Grids and Shapefiles for the Lower Pawcatuck River in Westerly, Rhode Island, and Stonington and North Stonington, Connecticut
A series of 11 digital flood-inundation maps were developed for a 5.5 mile reach of the Pawcatuck River in Westerly, Rhode Island and Stonington and North Stonington, Connecticut by the U.S. Geological Survey in cooperation with the Town of Westerly, Rhode Island and the Rhode Island Office of Housing and Community Development. The coverage of the maps extends from downstream from the Ashaway RiveFlood Inundation Grids and Shapefiles for the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island
A series of 15 digital flood-inundation shapefiles and grids were developed for a 10.2 mile reach of the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island by the U.S. Geological Survey in cooperation with Rhode Island Emergency Management Agency and U.S. Army Corps of Engineers. The coverage of the maps extends from downstream of Natick Pond Dam near State Route 33/Providence StrBathymetric data for St. Croix River at outlet to East Grand Lake and Forest City Dam Survey, United States-Canadian border between Maine and New Brunswick
These are survey data for the Forest City Dam at the Outlet to East Grand Lake on the St. Croix River between Maine and Canada. And they are bathymetric data surrounding the outlet dam collected with an Acoustic Doppler Current Profiler (ADCP)Precipitation and streamflow data for computing lag to peak at selected stations in Maine
These are rainfall and stream stage data collected at gaging sites in Maine. Data were collected from March to October from 2008 to 2015 and include stage data at crest stage gages, ratings to convert stage data to streamflow data, previously unpublished rainfall data, rainfall binned into specified time intervals, and storm files combining rainfall and streamflow data. Data were collected, compi - Publications
Filter Total Items: 30
Documentation and mapping of flooding from the January and March 2018 nor’easters in coastal New England
In January and March 2018, coastal Massachusetts experienced flooding from two separate nor’easters. To put the January and March floods into historical context, the USGS computed statistical stillwater elevations. Stillwater elevations recorded in January 2018 in Boston (9.66 feet relative to the North American Vertical Datum of 1988) have an annual exceedance probability of between 2 and 1 perceModel estimated baseflow for streams with endangered Atlantic Salmon in Maine, USA
We present a regression model for estimating mean August baseflow per square kilometer of drainage area to help resource managers assess relative amounts of baseflow in Maine streams with Atlantic Salmon habitat. The model was derived from mean August baseflows computed at 31 USGS streamflow gages in Maine. We use an ordinary least squares regression model to estimate mean August baseflow per unit2020 drought in New England
Below average and infrequent rainfall from May through September 2020 led to an extreme hydrologic drought across much of New England, with some areas experiencing a flash drought, reflecting its quick onset. The U.S. Geological Survey (USGS) recorded record-low streamflow and groundwater levels throughout the region. In September, the U.S. Department of Agriculture (2020) declared Aroostook CountEstimating flood magnitude and frequency on gaged and ungaged streams in Maine
Accurate estimates of flood frequency and magnitude on rivers and streams in Maine are a key component of effective flood risk management, flood mitigation, and flood recovery programs for the State. Flood-frequency estimates are published here for 148 streamgages in and adjacent to Maine. Equations are provided for users to compute flood-frequency estimates at any location on a stream that does nRiver channel response to dam removals on the lower Penobscot River, Maine, United States
Most geomorphology studies of dam removals have focused on sites with appreciable quantities of stored sediments. There is great interest in channel responses to sediment releases because of potential effects on aquatic and riparian habitats and human uses of these areas. Yet, behind many dams in the Northeast U.S. and other regions of the world only minor accumulations of sediment are present becA multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA
Factors affecting iron fouling in wet areas adjacent to roadways were investigated by collecting field rock cut and aqueous physicochemical data; developing exploratory predictive models; and developing geochemical models. Basic data included the identification of iron fouling from aerial imagery and field visits at 374 New Hampshire rock cut locations, and their associated rock-fill sites. BasedA multi-model approach toward understanding iron fouling at rock-fill drainage sites along roadways in New Hampshire, USA
Factors affecting iron fouling in wet areas adjacent to roadways were investigated by collecting field rock cut and aqueous physicochemical data; developing exploratory predictive models; and developing geochemical models. Basic data included the identification of iron fouling from aerial imagery and field visits at 374 New Hampshire rock cut locations, and their associated rock-fill sites. BasedFlood-inundation maps for the lower Pawcatuck River in Westerly, Rhode Island, and Stonington and North Stonington, Connecticut
A series of 11 digital flood-inundation maps was developed for a 5.5-mile reach of the lower Pawcatuck River in Westerly, Rhode Island, and Stonington and North Stonington, Connecticut, by the U.S. Geological Survey (USGS) in cooperation with the Town of Westerly, Rhode Island, and the Rhode Island Office of Housing and Community Development. The coverage of the maps extends from downstream from tFlood-inundation maps for the Pawtuxet River in West Warwick, Warwick, and Cranston, Rhode Island
A series of 15 digital flood-inundation maps was developed for a 10.2-mile reach of the Pawtuxet River in the municipalities of West Warwick, Warwick, and Cranston, Rhode Island, by the U.S. Geological Survey (USGS), in cooperation with the Rhode Island Emergency Management Agency and the U.S. Army Corps of Engineers. The coverage of the maps extends downstream from Natick Pond dam near State RoutEstimating lag to peak between rainfall and peak streamflow with a mixed-effects model
We test the use of a mixed-effects model for estimating lag to peak for small basins in Maine (drainage areas from 0.8 to 78 km2). Lag to peak is defined as the time between the center of volume of the excess rainfall during a storm event and the resulting peak streamflow. A mixed-effects model allows for multiple observations at sites without violating model assumptions inherent in traditional orEstimation of unregulated monthly, annual, and peak streamflows in Forest City Stream and lake levels in East Grand Lake, United States-Canada border between Maine and New Brunswick
The U.S. Geological Survey, in cooperation with the International Joint Commission, compiled historical data on regulated streamflows and lake levels and estimated unregulated streamflows and lake levels on Forest City Stream at Forest City, Maine, and East Grand Lake on the United States-Canada border between Maine and New Brunswick to study the effects on streamflows and lake levels if two or alHydrologic and hydraulic analyses of Great Meadow wetland, Acadia National Park, Maine
The U.S. Geological Survey completed hydrologic and hydraulic analyses of Cromwell Brook and the Sieur de Monts tributary in Acadia National Park, Maine, to better understand causes of flooding in complex hydrologic and hydraulic environments, like those in the Great Meadow wetland and Sieur de Monts Spring area. Regional regression equations were used to compute peak flows with from 2 to 100-year - News