USGS hydrologist, Erin Leahy, collects sediment samples at the upstream gage on Chicken Creek in the Tualatin River National Wildlife Refuge.
Erin Leahy
Erin Leahy is a Hydrologist and Code 4 Supervisor with the USGS Oregon Water Science Center.
Project management: Independently manage multiple projects with various associated tasks and goals. Interview, onboard and train new staff. Develop and manage budgets. Manage and coordinate 10+ staff members to ensure efficient workflow and workload. Plan and coordinate site construction including obtaining proper permitting and site design. Create project schedules and monitor status to ensure project goals are met. Plan and lead sampling teams. Review various long-term datasets to ensure high quality. Develop and maintain working relationships with federal, state and local government agencies along with non-profit organizations. Maintain consistent and clear communication with partners.
Hydrologic data: Metadata specialist for the ORWSC. Review and create metadata for various types of datasets and shepherd them through the data release process. Interpret patterns and trends in continuous datasets to better understand instream processes. Audit continuous water quality records to ensure the highest quality data.
Fieldwork: Operated multiple long-term, continuous water-quality sites. Responsibilities included maintaining and calibrating water-quality equipment, processing data to ensure high-quality standards. Coordinate and participate in suspended-sediment sampling efforts during storm-events for multiple projects. Manage and participate in temperature synoptics assessing spatial variability in surface-water temperature in urban ponds. Investigate spatial and temporal temperature and streamflow variation in beaver-effected stream reaches. Collect and process discrete water-quality data, including sampling for the National Water-Quality Assessment Program using parts-per-billion protocols. Install and maintain continuous surface water and groundwater gaging stations. Collect bathymetric and surface elevation data using both total station and real-time kinematic (RTK) instruments.
Communication: Accomplished at developing presentations for a variety of audiences. Successfully delivered over a dozen presentations. Coauthored multiple papers that will be published in 2025. Created numerous maps for publication.
Professional Experience
Hydrologist
Code 4 Supervisor
Metadata Specialist
Cartographer
Education and Certifications
M.S. Environmental Management, Portland State University, 2018
GIS Graduate Certificate, Portland State University, 2016
B.S. Environmental Studies, Portland State University, 2014
Wildland Fire Incident Qualification Card, 2021
Science and Products
Evaluating sediment transport in Chicken Creek
Fernhill Natural Treatment Wetlands
Johnson Creek Basin Hydrologic Monitoring Study
Tualatin River Basin Water Quality Assessment
City Beavers: Tualatin River Basin Beaver Study
Plankton taxonomy and water quality in the Tualatin River Basin to the west of Portland, Oregon, during the summers of 2019-21
Water Temperature, Dissolved Oxygen, and pH Point Measurements from a Beaver Pond along Fanno Creek, Oregon, on four hot days in summers 2016-17
USGS hydrologist, Erin Leahy, collects sediment samples at the upstream gage on Chicken Creek in the Tualatin River National Wildlife Refuge.
USGS hydrologist, Erin Leahy, collecting data in Chicken Creek in the Tualatin River National Wildlife Refuge. The USGS operates two water-quality monitors along Chicken Creek.
USGS hydrologist, Erin Leahy, collecting data in Chicken Creek in the Tualatin River National Wildlife Refuge. The USGS operates two water-quality monitors along Chicken Creek.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
USGS hydrologist, Steven Sobieszcyk, on stage at Alberta Rose Theater talking about the science behind the Eagle Creek Fire response.
USGS hydrologist, Steven Sobieszcyk, on stage at Alberta Rose Theater talking about the science behind the Eagle Creek Fire response.
Beavers and their dams can substantially change the storage and movement of water through a stream reach. The magnitude of this change is, in part, a function of the number and type of dams plus stream characteristics.
Beavers and their dams can substantially change the storage and movement of water through a stream reach. The magnitude of this change is, in part, a function of the number and type of dams plus stream characteristics.
Beaver dams and associated ponding affect sediment transport and trapping by pushing water onto the floodplain and decreasing stream velocity, allowing for increased sediment deposition.
Beaver dams and associated ponding affect sediment transport and trapping by pushing water onto the floodplain and decreasing stream velocity, allowing for increased sediment deposition.
Beaver dams and ponds alter the movement and storage of water as well as the water quality in a stream reach. To date, little work has been done to quantify the effects of beaver activity on water quality in urban streams.
Beaver dams and ponds alter the movement and storage of water as well as the water quality in a stream reach. To date, little work has been done to quantify the effects of beaver activity on water quality in urban streams.
Beaver dams and ponds fundamentally alter how water moves through a stream reach. Semi-porous dams can impound water, leading to backwatering, floodplain inundation, and overall changes in wetted area, depth, and velocity.
For this part of the study, USGS:
Beaver dams and ponds fundamentally alter how water moves through a stream reach. Semi-porous dams can impound water, leading to backwatering, floodplain inundation, and overall changes in wetted area, depth, and velocity.
For this part of the study, USGS:
Populations of North American beaver (Castor canadensis) have increased in recent years due to decreased trapping, habitat restoration, and recognition of their importance as a keystone species in stream ecosystems (Pollock and others, 2017).
Populations of North American beaver (Castor canadensis) have increased in recent years due to decreased trapping, habitat restoration, and recognition of their importance as a keystone species in stream ecosystems (Pollock and others, 2017).
Meet Bob.
Bob is a beaver.
Meet Bob.
Bob is a beaver.
Adult and juvenile beaver near Windrose, Oregon
Adult and juvenile beaver near Windrose, Oregon

Beaver along bank of pond in Tualatin River Basin, OR
Beaver along bank of pond in Tualatin River Basin, OR
This dragonfly is called a Cardinal Meadowhawk.
This dragonfly is called a Cardinal Meadowhawk.
Beaver swimming in Summer Lake, Oregon.
Beaver swimming in Summer Lake, Oregon.
Beaver eating at Summer Lake, OR
Beaver eating at Summer Lake, OR
Beaver swimming in Summer Lake, OR
Beaver swimming in Summer Lake, OR
Science and Products
Evaluating sediment transport in Chicken Creek
Fernhill Natural Treatment Wetlands
Johnson Creek Basin Hydrologic Monitoring Study
Tualatin River Basin Water Quality Assessment
City Beavers: Tualatin River Basin Beaver Study
Plankton taxonomy and water quality in the Tualatin River Basin to the west of Portland, Oregon, during the summers of 2019-21
Water Temperature, Dissolved Oxygen, and pH Point Measurements from a Beaver Pond along Fanno Creek, Oregon, on four hot days in summers 2016-17
USGS hydrologist, Erin Leahy, collects sediment samples at the upstream gage on Chicken Creek in the Tualatin River National Wildlife Refuge.
USGS hydrologist, Erin Leahy, collects sediment samples at the upstream gage on Chicken Creek in the Tualatin River National Wildlife Refuge.
USGS hydrologist, Erin Leahy, collecting data in Chicken Creek in the Tualatin River National Wildlife Refuge. The USGS operates two water-quality monitors along Chicken Creek.
USGS hydrologist, Erin Leahy, collecting data in Chicken Creek in the Tualatin River National Wildlife Refuge. The USGS operates two water-quality monitors along Chicken Creek.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
View of lake at Fernhill Natural Treatment Wetlands.
USGS hydrologist, Steven Sobieszcyk, on stage at Alberta Rose Theater talking about the science behind the Eagle Creek Fire response.
USGS hydrologist, Steven Sobieszcyk, on stage at Alberta Rose Theater talking about the science behind the Eagle Creek Fire response.
Beavers and their dams can substantially change the storage and movement of water through a stream reach. The magnitude of this change is, in part, a function of the number and type of dams plus stream characteristics.
Beavers and their dams can substantially change the storage and movement of water through a stream reach. The magnitude of this change is, in part, a function of the number and type of dams plus stream characteristics.
Beaver dams and associated ponding affect sediment transport and trapping by pushing water onto the floodplain and decreasing stream velocity, allowing for increased sediment deposition.
Beaver dams and associated ponding affect sediment transport and trapping by pushing water onto the floodplain and decreasing stream velocity, allowing for increased sediment deposition.
Beaver dams and ponds alter the movement and storage of water as well as the water quality in a stream reach. To date, little work has been done to quantify the effects of beaver activity on water quality in urban streams.
Beaver dams and ponds alter the movement and storage of water as well as the water quality in a stream reach. To date, little work has been done to quantify the effects of beaver activity on water quality in urban streams.
Beaver dams and ponds fundamentally alter how water moves through a stream reach. Semi-porous dams can impound water, leading to backwatering, floodplain inundation, and overall changes in wetted area, depth, and velocity.
For this part of the study, USGS:
Beaver dams and ponds fundamentally alter how water moves through a stream reach. Semi-porous dams can impound water, leading to backwatering, floodplain inundation, and overall changes in wetted area, depth, and velocity.
For this part of the study, USGS:
Populations of North American beaver (Castor canadensis) have increased in recent years due to decreased trapping, habitat restoration, and recognition of their importance as a keystone species in stream ecosystems (Pollock and others, 2017).
Populations of North American beaver (Castor canadensis) have increased in recent years due to decreased trapping, habitat restoration, and recognition of their importance as a keystone species in stream ecosystems (Pollock and others, 2017).
Meet Bob.
Bob is a beaver.
Meet Bob.
Bob is a beaver.
Adult and juvenile beaver near Windrose, Oregon
Adult and juvenile beaver near Windrose, Oregon

Beaver along bank of pond in Tualatin River Basin, OR
Beaver along bank of pond in Tualatin River Basin, OR
This dragonfly is called a Cardinal Meadowhawk.
This dragonfly is called a Cardinal Meadowhawk.
Beaver swimming in Summer Lake, Oregon.
Beaver swimming in Summer Lake, Oregon.
Beaver eating at Summer Lake, OR
Beaver eating at Summer Lake, OR
Beaver swimming in Summer Lake, OR
Beaver swimming in Summer Lake, OR