Christopher L Gazoorian is a Hydrologist at the New York Water Science Center.
Chris Gazoorian currently serves as the Surface Water Specialist for the USGS New York Water Science Center. Prior to this, he served as a Hydrologist, leading studies and field data collection relating to surface-water, groundwater and water-quality. Chris' research interests include innovative use of non-contact sensors, ice-jam flood monitoring, and streamflow uncertainly and statistical analysis.
As a Hydrologists at U.S. Geological Survey, the New York Water Science Center
- Estimation of unaltered daily streamflow at rural ungagged locations
- Streamflow statistics and trends
- Ice Jam monitoring and modeling in the Mohawk River, Schenectady, NY
- Computation of peak streamflow in open channels and through control structures by direct and indirect methods
- Flood documentation and flood frequency trends
- Develop streamflow ratings for stage-discharge and index-velocity relations.
As a Student Hydrologist at U.S. Geological Survey, New York Water Science Center
- Assisted with multiple research projects investigating biogeochemical nutrient cycles, acid deposition and water.
- Analyzed soil and water properties including total C and N using a Carlo Erba EA 1110 elemental analyzer.
- Reported data for publication in scientific journals and USGS reports.
- Developed the NY WSC Standard Operating Procedure manuals for soil analyses.
- Instructed students on analyses procedures and tracked progress to meet deadlines.
- Collected water, soil, sediment and biological samples and maintained field sites.
As a Graduate Research Assistant at State University of New York at Albany, Department of Geography and Planning
- Conducted soil analyses on archived and new samples to identify centennial scale changes in soil C in a Russian steppe.
Professional Experience
U.S. Geological Survey, New York Water Science Center as Hydrologist February 2005 - present
U. S. Geological Survey, New York Water Science Center as Student Hydrologist August 2002 – February 2005
State University of New York at Albany, Department of Geography and Planning as Graduate Research Assistant May 2002 – August 2002
Education and Certifications
Master of Arts, Geography, 2004, State University of New York at Albany
Certificate of Graduate Study, GIS & Spatial Analysis, 2003, State University of New York at Albany
Bachelor of Science, Geology, 2002, State University of New York at Albany
Science and Products
Methods for Estimation Flood Magnitude and Frequency at Ungaged Streams in New York, excluding Long Island
An Analysis of Trends in the Magnitude of Floods in Urbanized Watersheds on Long Island, New York
Lake Ontario Flood Monitoring and Mapping
Monthly Hydrologic Conditions for New York
New York Flood Information
Mohawk River Ice Jam Monitoring
Flood-inundation mapping of Egypt Creek, Dryden, Tompkins County
A New Tool for Estimating Daily Mean Streamflow Statistics at Rural Streams in New York State, excluding Long Island
Surface-Water Data Collection in New York
Geospatial Datasets of Water Surface Elevation and Water Depth in New York City, NY Associated with the Remnants of Hurricane Ida – September 1, 2021
Main channel river water temperature collected along the East Branch, West Branch, and mainstem Delaware River down to Lordville near Handcock, NY, USA in summer 2021
Stream Temperature, Dissolved Radon, and Stable Water Isotope Data Collected along Headwater Streams in the Upper Neversink River Watershed, NY, USA (ver. 2.0, April 2023)
Depth to bedrock determined from passive seismic measurements, Neversink River watershed, NY (USA)
Flood inundation map geospatial datasets for Lake Ontario, New York
Thermal infrared and photogrammetric data collected by drone for hydrogeologic characterization around two US Geological Survey Next Generation Water Observing Systems stream gage locations near Claryville, NY, USA
Adjusting design floods for urbanization across groundwater-dominated watersheds of Long Island, NY
A multiscale approach for monitoring groundwater discharge to headwater streams by the U.S. Geological Survey Next Generation Water Observing System Program—An example from the Neversink Reservoir watershed, New York
A comparison of methods for streamflow uncertainty estimation
Estimates of natural streamflow at two streamgages on the Esopus Creek, New York, water years 1932 to 2012
Estimation of unaltered daily mean streamflow at ungaged streams of New York, excluding Long Island, water years 1961-2010
Changes in low-flow frequency from 1976-2006 at selected streamgages in New York, excluding Long Island
New York Streamflow Estimation Tool
The New York Streamflow Estimation Tool produces a complete estimated daily mean time series from which daily flow statistics can be estimated and a means for quantitative flow assessments at ungaged locations to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.
Science and Products
- Science
Methods for Estimation Flood Magnitude and Frequency at Ungaged Streams in New York, excluding Long Island
Summary: Extreme flooding can threaten life and property in flood-prone areas, as well as cause damage to critical infrastructure along roadways and canals. The effective management of these areas, and appropriate design of structures along rivers and streams, relies on understanding the magnitude and frequency of floods at gaged locations, and the ability to estimate these data at ungaged streaAn Analysis of Trends in the Magnitude of Floods in Urbanized Watersheds on Long Island, New York
Summary: This study aims to do a thorough analysis of trends in peak streamflows on Long Island. Reliable information about the magnitude and frequency of floods is essential for flood insurance studies, flood-plain management, and the design of transportation and water-conveyance infrastructure, such as roads, bridges, culverts, dams, and levees. Federal, State, regional, and local officials needLake Ontario Flood Monitoring and Mapping
Problem– Lake Ontario experienced period-of-record (1918-2017) maximum monthly average water levels during May through July 2017. NOAA lake gages recorded instantaneous peaks-of record, 249.2 at Olcott, 249.1 at Rochester, and 249.0 at Oswego and St. Vincent. These high water levels along with wind-generated waves caused flooding of thousands of residences and businesses and the erosion of miles o...Monthly Hydrologic Conditions for New York
The U.S. Geological Survey New York Water Science Center’s monthly summary reports and tables of hydrologic conditions for surface and ground water list the station, county, period of record, and several statistics, including color-coded percent exceedance* categories based on average monthly conditions for the period of record at each station.New York Flood Information
For emergency situations, please contact Chris Gazoorian, Surface Water Specialist at the USGS New York Water Science Center or call our general number (518) 285-5600 and follow the directions to leave voicemail which will be immediately forwarded to a responsible party and responded to as quickly as possible.Mohawk River Ice Jam Monitoring
The Mohawk River near Schenectady, NY is prone to ice jams during periods of river-ice break-up. Ice jams in this reach typically form at channel constrictions, bridge piers, lock and dam structures, and sections with a reduced floodplain (Foster and others, 2011). Ice jam related flooding can result from backwater associated with the jam or from water released downstream when a jam fails...Flood-inundation mapping of Egypt Creek, Dryden, Tompkins County
Problem – Flooding is an annual problem along Egypt Creek in Dryden. Increased runoff from expanding development, sediment clogged channels, and undersized culverts that cannot convey increased flows contribute to the problem. Flood maps for extreme floods are available through the effective FEMA flood insurance study (FEMA, 1978), but these maps, which became effective in 1979, are considered noA New Tool for Estimating Daily Mean Streamflow Statistics at Rural Streams in New York State, excluding Long Island
The lakes, rivers, and streams of New York State provide an essential water resource for the State. The information provided by time series hydrologic data is essential to understanding ways to promote healthy instream ecology and to strengthen the scientific basis for sound water management decision making in New York. The U.S. Geological Survey, in cooperation with The Nature Conservancy and theSurface-Water Data Collection in New York
Problem Surface-water information is needed for planning, design, hazard warning, and operation and management in water-related fields such as water supply, hydroelectric power, flood control, irrigation, bridge and culvert design, wildlife management, pollution abatement, flood-plain management, and water-resources development. Appropriate historical and real-time surface-water data, such as st - Data
Geospatial Datasets of Water Surface Elevation and Water Depth in New York City, NY Associated with the Remnants of Hurricane Ida – September 1, 2021
The remnants of Hurricane Ida produced significant rainfall over the five boroughs of New York City (NYC) for several hours on September 1st, 2021. The long-duration, high-intensity rainfall resulted in extensive inundation of streets, buildings, subways, and other public spaces. In response to a Federal Emergency Management Agency (FEMA) mission assignment, the U.S. Geological Survey (USGS) identMain channel river water temperature collected along the East Branch, West Branch, and mainstem Delaware River down to Lordville near Handcock, NY, USA in summer 2021
The Upper Delaware River is a unique example of an aquatic system where summer river temperature is actively managed for ecological purposes. River temperature at the mainstem Delaware River at Lordville, NY gage (USGS 01427207) is targeted to remain below 25 degrees C, with warm events potentially mitigated via directed upstream reservoir releases, a process guided by predictive tools. These direStream Temperature, Dissolved Radon, and Stable Water Isotope Data Collected along Headwater Streams in the Upper Neversink River Watershed, NY, USA (ver. 2.0, April 2023)
This data release contains three data types that could potentially be used to infer spatiotemporal variability in groundwater discharge processes, along with other research and monitoring purposes: 1) Temporally continuous stream channel water temperature and adjacent streambank air temperature time series data (generally starting November 2020) as well as limited temperature data from May to OctoDepth to bedrock determined from passive seismic measurements, Neversink River watershed, NY (USA)
This data release documents streambed sediment thickness in the Neversink watershed (NY) as determined by field observations and HVSR passive seismic measurements, and were collected as an extension of a previous data set collected in the same watershed (see Associated Items). These measurements were made between May 17, 2021 and May 21, 2021 using MOHO Tromino three-component seismometers (MOHO,Flood inundation map geospatial datasets for Lake Ontario, New York
Static flood inundation boundary extents were created along the entire shoreline of Lake Ontario in Cayuga, Jefferson, Monroe, Niagara, Orleans, Oswego, and Wayne Counties in New York by using recently acquired (2007, 2010, 2014, and 2017) light detection and ranging (lidar) data. The flood inundation maps, accessible through the USGS Flood Inundation Mapping Program website at https://www.usgs.goThermal infrared and photogrammetric data collected by drone for hydrogeologic characterization around two US Geological Survey Next Generation Water Observing Systems stream gage locations near Claryville, NY, USA
The U.S. Geological Survey (USGS) collected low-altitude (typically 200-350 ft above land surface) airborne thermal infrared, and visual imagery data via a multirotor, small unoccupied aircraft system (UAS or 'drone') deployed along the river corridor encompassing two U.S. Geological Survey Next Generation Water Observing Systems (NGWOS) stream gage locations near Claryville, NY, USA. One site is - Multimedia
- Publications
Adjusting design floods for urbanization across groundwater-dominated watersheds of Long Island, NY
The magnitude and variability of floods have increased for many nontidal streams on Long Island (LI), NY since the mid-20th century. One of the most densely populated regions of the United States, LI has experienced amplified floods in step with increases in impervious land cover, storm, and sanitary sewers that have accompanied urban development. To better understand the drivers of observed floodAuthorsRobin Lee Glas, Jory Seth Hecht, Amy E. Simonson, Christopher L. Gazoorian, Christopher E. SchubertA multiscale approach for monitoring groundwater discharge to headwater streams by the U.S. Geological Survey Next Generation Water Observing System Program—An example from the Neversink Reservoir watershed, New York
Groundwater-stream connectivity across mountain watersheds is critical for supporting streamflow during dry times and keeping streams cool during warm times, yet U.S. Geological Survey (USGS) stream measurements are often sparse in headwaters. Starting in 2019, the USGS Next Generation Water Observing System Program developed a multiscale methods and technology testbed approach to monitoring grounAuthorsMartin A. Briggs, Christopher L. Gazoorian, Daniel H. Doctor, Douglas A. BurnsA comparison of methods for streamflow uncertainty estimation
Streamflow time series are commonly derived from stage‐discharge rating curves, but the uncertainty of the rating curve and resulting streamflow series are poorly understood. While different methods to quantify uncertainty in the stage‐discharge relationship exist, there is limited understanding of how uncertainty estimates differ between methods due to different assumptions and methodological choAuthorsJulie E. Kiang, Christopher L. Gazoorian, Hillary McMillan, Gemma Coxon, Jerome Le Coz, Ida Westerberg, Arnaud Belleville, Damien Sevrez, Anna Sikorska, Asgeir Petersen‐Øverleir, Trond Reitan, Jim Freer, Benjamin Renard, Valentin Mansanarez, Robert R. Mason,Estimates of natural streamflow at two streamgages on the Esopus Creek, New York, water years 1932 to 2012
Streamflow in the Esopus Creek watershed is altered by two major watershed management activities carried out by the New York City Department of Environmental Protection as part of its responsibility to maintain a water supply for New York City: (1) diversion of water from the Schoharie Creek watershed to the Esopus Creek through the Shandaken Tunnel, and (2) impoundment of the Esopus Creek by a daAuthorsDouglas A. Burns, Christopher L. GazoorianEstimation of unaltered daily mean streamflow at ungaged streams of New York, excluding Long Island, water years 1961-2010
The lakes, rivers, and streams of New York State provide an essential water resource for the State. The information provided by time series hydrologic data is essential to understanding ways to promote healthy instream ecology and to strengthen the scientific basis for sound water management decision making in New York. The U.S. Geological Survey, in cooperation with The Nature Conservancy and theAuthorsChristopher L. GazoorianChanges in low-flow frequency from 1976-2006 at selected streamgages in New York, excluding Long Island
Many Federal, State, and local agencies use low-flow data to establish water-use policy and help determine the total maximum daily loads and effluent limits of point and nonpoint sources of contamination of surface water during periods of decreased streamflow. Low-flow magnitude and frequency are used often by water-supply planners, reservoir managers, and hydroelectric facilities to manage waterAuthorsThomas P. Suro, Christopher L. Gazoorian - Software
New York Streamflow Estimation Tool
The New York Streamflow Estimation Tool produces a complete estimated daily mean time series from which daily flow statistics can be estimated and a means for quantitative flow assessments at ungaged locations to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.
- News