Flood-frequency analysis provides information about the magnitude and frequency of floods based on records of annual maximum instantaneous peak discharges. Accurate flood-frequency estimates, created using consistent and uniformly applied methods, are a key component of any effective flood risk and management program. This is a list of current USGS flood frequency reports published by state.
NOTICE: Potential computational issues in the PeakFQ software continue to be investigated in collaboration with the U.S. Army Corps of Engineers (USACE). Refined user guidance and/or updated methodology documentation will be developed and made available, if needed.
For detailed information, please visit this page.
Flood Frequency Overview
Floods are dangerous natural hazards that can threaten lives, livelihoods, and property. Without information on flood risk, the planning, design, and management of infrastructure along rivers would be forced to proceed without quantitative scientific analysis. Flood-frequency analysis provides information about the magnitude and frequency of flood discharges based on records of annual maximum instantaneous peak discharges collected at streamgages. In essence, flood-frequency analysis is used to estimate the probability of flooding at specific river locations.
Accurate estimates of flood frequency and magnitude are a key component of any effective nationwide flood risk management and flood damage abatement program. In addition to accuracy, methods for estimating flood risk must be uniformly and consistently applied because management of the Nation’s water and related land resources is a collaborative effort involving multiple actors including most levels of government and the private sector.
To ensure consistency in flood-frequency analysis, multiple federal agencies have worked together to produce the Guidelines for Determining Flood Flow Frequency - Bulletin 17C, released in 2019. Updates include: adoption of a generalized representation of flood data that allows for interval and censored data types; a new method, called the Expected Moments Algorithm, which extends the method of moments so that it can accommodate interval data; a generalized approach to identification of low outliers in flood data; and an improved method for computing confidence intervals. Federal agencies are requested to use these Guidelines in all planning activities involving water and related land resources. State, local, and private organizations are encouraged to use these Guidelines to assure uniformity in the flood-frequency estimates that all agencies concerned with flood risk should use for Federal planning decisions.
For additional information on the basics of flood-frequency analysis, see also The 100-Year-Flood-It’s All About Chance (USGS General Information Product 106) and our 100-Year Flood webpage (USGS Water Science School).
USGS Reports: Flood Frequency and Regional Skew
Below is a list of the most recent flood frequency reports published by the USGS and organized by state. This list includes reports pertaining to regional skew, as well as regional annual exceedance probability equations for both peak flow and flood-duration flows. It will be updated as new reports are published.
As B17C recommends weighting the at-site skew with regional skew, this list provides the most current regional skew study for each state, which include both B17C recommended BGLS regional skew as well as other methodologies. If a B-GLS regional skew is not available, it is recommended that users consult with the USGS to determine the availability of alternate regional skew estimates. If no alternatives are available, then use the B17B map.
Reports which use the flood-frequency methods recommended in Bulletin 17C will be denoted with “B17C.”
For additional information, please contact your local Water Science Center or email gs_b17c@usgs.gov.
ALABAMA
Peak Flow
SIR 2007-5204, Magnitude and Frequency of Floods in Alabama, 2003
SIR 2010-2012, Magnitude and Frequency of Floods for Urban Streams in Alabama, 2007
B17C
SIR 2020-5032, Magnitude and Frequency of Floods in Alabama, 2015
ALASKA
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5024, Estimating flood magnitude and frequency at gaged and ungaged sites on streams in Alaska and conterminous basins in Canada, based on data through water year 2012
ARIZONA
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2014-5211, Methods for estimating magnitude and frequency of floods in Arizona, developed with unregulated and rural peak-flow data through water year 2010
B17C Flood-Duration Flows with B17C B-GLS Regional Skews
SIR 2014-5109, Methods for estimating magnitude and frequency of 1-, 3-, 7-, 15-, and 30-day flood-duration flows in Arizona
ARKANSAS
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5081, Methods for estimating annual exceedance probability discharges for streams in Arkansas, based on data through water year 2013
B17C
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
CALIFORNIA
B17C B-GLS Regional Skew
SIR 2010-5260, Regional skew for California, and flood frequency for selected sites in the Sacramento-San Joaquin River Basin, based on data through water year 2006
B17C Peak Flow
SIR 2012-5113, Methods for determining magnitude and frequency of floods in California, based on data through water year 2006
B17C Flood-Duration Flows with B17C B-GLS Regional Skews
SIR 2012-5130, Development of regional skews for selected flood durations for the Central Valley Region, California, based on data through water year 2008
COLORADO
B17C Peak Flow
SIR 2016-5099, Paleoflood investigations to improve peak-streamflow regional-regression equations for natural streamflow in eastern Colorado
Peak Flow
SIR 2009-5136, Regional Regression Equations for Estimation of Natural streamflow Statistics in Colorado
Updated peak flow/low flow/max flow/duration flow regression report coming soon...
CONNECTICUT
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
Peak Flow
SIR 2020-5054, Estimating Flood Magnitude and Frequency on Streams and Rivers in Connecticut, Based on Data Through Water Year 2015
DELAWARE
Peak Flow
SIR 2006-5146, Magnitude and Frequency of Floods on Nontidal Streams in Delaware
B17C
SIR 2022-5005, Peak-Flow and Low-Flow Magnitude Estimates at Defined Frequencies and Durations for Nontidal Streams in Delaware
GEORGIA
Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2023-5065, Effects of Impoundments on Selected Flood-Frequency and Daily Mean Streamflow Characteristics in Georgia, South Carolina, and North Carolina
SIR 2023-5006, Magnitude and Frequency of Floods for Rural Streams in Georgia, South Carolina, and North Carolina, 2017—Results
SIR 2014-5030, Methods for Estimating the Magnitude and Frequency of Floods for Urban and Small, Rural Streams in Georgia, South Carolina, and North Carolina, 2011
HAWAII
Peak Flow
SIR 2023-5014, Magnitude and Frequency of Floods on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, Based on Data through Water Year 2020
IDAHO
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5083, Estimating peak-flow frequency statistics for selected gaged and ungaged sites in naturally flowing streams and rivers in Idaho
ILLINOIS
Peak Flow
Research Report FHWA-ICT-23-014, Estimating Peak-flow Quantiles for Selected Annual Exceedance Probabilities in Illinois
FHWA-ICT-23-014, Estimating peak-flow quantiles for selected annual exceedance probabilities in Illinois
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2016-5050, Estimation of Peak Discharge Quantiles for Selected Annual Exceedance Probabilities in Northeastern Illinois
INDIANA
Peak Flow
Rao, A. R. Flood Frequency Relationships for Indiana. Publication FHWA/IN/JTRP-2005/18. Joint Transportation Research Program, Indiana Department of Transportation and Purdue University, West Lafayette, Indiana, 2006.
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
IOWA
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2013-5086, Methods for Estimating Annual Exceedance-Probability Discharges for Streams in Iowa, Based on Data through Water Year 2010
SIR 2015-5055, Comparisons of Estimates of Annual Exceedance-Probability Discharges for Small Drainage Basins in Iowa, Based on Data through Water Year 2013
KANSAS
Peak Flow & Regional Skew
WRIR 00-4079, Estimation of Peak Streamflows for Unregulated Streams in Kansas
SIR 2017-5063, Methods for estimating annual exceedance-probability streamflows for streams in Kansas based on data through water year 2015
KENTUCKY
Peak Flow & Regional Skew
WRIR 97-4219, Estimation of peak-discharge frequency of urban streams in Jefferson County, Kentucky
WRIR 03-4180, Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals
LOUISIANA
Peak Flow
SIR 2024-5031, Magnitude and Frequency of Floods in the Coastal Plain Region of Louisiana, 2016
TR No. 60, (1998) Floods in Louisiana, Magnitude and Frequency, Fifth Edition. In progress (coming soon)
B17C
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
A Coastal Plains peakflow report is coming soon...
B17C B-GLS Regional Skew
Appendix of: SIR 2016-5081, Methods for estimating annual exceedance probability discharges for streams in Arkansas, based on data through water year 2013
MAINE
Peak Flow & Regional Skew
WRIR 99-4008, Estimating the Magnitude of Peak Flows for Streams in Maine for Selected Recurrence Intervals
SIR 2020-5092, Estimating Flood Magnitude and Frequency on Gaged and Ungaged Streams in Maine
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
MARYLAND
Peak Flow
Application of Hydrologic Methods in Maryland
MASSACHUSETTS
B17C Peak Flow
SIR 2016-5156, Magnitude of flood flows at selected annual exceedance probabilities for streams in Massachusetts
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
MICHIGAN
Peak Flow
WRIR 84-4207, Statistical Models for Estimating Flow Characteristics of Michigan Streams, 1984
MINNESOTA
Peak Flow
SIR 2023-5079, Techniques for Estimating the Magnitude and Frequency of Peak Flows on Small Streams in Minnesota, Excluding the Rainy River Basin, Based on Data Through Water Year 2019
B17C
SIR 2019-5012, Techniques for Estimating the Magnitude and Frequency of Peak Flows on Small Streams in the Binational U.S. and Canadian Lake of the Woods–Rainy River Basin Upstream from Kenora, Ontario, Canada, Based on Data through Water Year 2013
MISSISSIPPI
Peak Flow & Regional Skew (combined report)
SIR 2018-5148, Flood Frequency of Rural Streams in Mississippi, 2013
B17C
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
MISSOURI
B17C Peak Flow & B17C Regional Skew (combined report)
SIR 2014-5165, Methods for Estimating Annual Exceedance-Probability Discharges and Largest Recorded Floods for Unregulated Streams in Rural Missouri
SIR 2010-5073, Estimation of the Magnitude and Frequency of Floods in Urban Basins in Missouri
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
MONTANA
Peak Flow & Regional skew (combined report)
WRIR 2015-5019, Montana StreamStats
SIR 2020-5142, Regional Regression Equations Based on Channel-Width Characteristics to Estimate Peak-Flow Frequencies at Ungaged Sites in Montana Using Peak-Flow Frequency Data through Water Year 2011
Other
FS 2024-3035, June 2022 Floods in the Upper Yellowstone River Basin
NEBRASKA
Peak Flow & Regional skew (combined report)
WRIR 99-4032, Peak-Flow Frequency Relations and Evaluation of the Peak-Flow Gaging Network in Nebraska
NEVADA
Peak Flow & Regional skew (combined report)
WSP 2433 (1997), Methods for Estimating Magnitude and Frequency of Floods in the Southwestern United States
Update coming soon...
NEW HAMPSHIRE
Peak Flow
SIR 2008-5206, Estimation of Flood Discharges at Selected Recurrence Intervals for Streams in New Hampshire
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
NEW JERSEY
Peak Flow & Regional skew (combined report)
SIR 2009-5167, Methodology for Estimation of Flood Magnitude and Frequency for New Jersey Streams
NEW MEXICO
Peak Flow & Regional skew (combined report)
SIR 2008-5119, Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas
WSP 2433, Methods for estimating magnitude and frequency of floods in the southwestern United States
SIR 2006-5306, Analysis of the Magnitude and Frequency of Peak Discharges for the Navajo Nation in Arizona, Utah, Colorado, and New Mexico
NEW YORK
Peak Flow
SIR 2006-5112, Magnitude and Frequency of Floods in New York
Regional Skew
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2021-5015, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of Eastern New York and Pennsylvania, Based on Data Through Water Year 2013
NORTH CAROLINA
Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2023-5065, Effects of Impoundments on Selected Flood-Frequency and Daily Mean Streamflow Characteristics in Georgia, South Carolina, and North Carolina
SIR 2023-5006, Magnitude and Frequency of Floods for Rural Streams in Georgia, South Carolina, and North Carolina, 2017—Results
NORTH DAKOTA
Peak Flow & Regional skew (combined report)
SIR 2015-5096, Regional regression equations to estimate peak-flow frequency at sites in North Dakota using data through 2009
OHIO
Peak Flow
WSP 2432, Estimation of peak-frequency relations, flood hydrographs, and volume-duration-frequency relations of ungaged small urban streams in Ohio
B17C
SIR 2019-5018, Flood-Frequency Estimates for Ohio Streamgages Based on Data through Water Year 2015 and Techniques for Estimating Flood-Frequency Characteristics of Rural, Unregulated Ohio Streams
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
OKLAHOMA
Peak Flow
SIR 2015-5134, Methods for estimating the magnitude and frequency of peak streamflows at ungaged sites in and near the Oklahoma Panhandle
B17C
SIR 2019-5043, Methods for Estimating the Magnitude and Frequency of Peak Streamflows for Unregulated Streams in Oklahoma Developed by Using Streamflow Data Through 2017
Regional Skew
SIR 2009-5135, Statistical Summaries of Streamflow in and near Oklahoma Through 2007
OREGON
Peak Flow & Regional skew (combined report)
SIR 2005-5116, Estimation of Peak Discharges for Rural, Unregulated Streams in Western Oregon
WSP 2433 (1997), Methods for Estimating Magnitude and Frequency of Floods in the Southwestern United States
B17C B-GLS Regional Skew
Appendix of: SIR 2016-5118, Magnitude, frequency, and trends of floods at gaged and ungaged sites in Washington, based on data through water year 2014 (ver 1.1, October 2016)
PENNSYLVANIA
Peak Flow
SIR 2008-5102, Regression Equations for Estimating Flood Flows at Selected Recurrence Intervals for Ungaged Streams in Pennsylvania
B17C
SIR 2019-5094, Development of Regression Equations for the Estimation of Flood Flows at Ungaged Streams in Pennsylvania
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2021-5015, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of Eastern New York and Pennsylvania, Based on Data Through Water Year 2013
PUERTO RICO
Peak Flow & B17C Regional skew (combined report)
SIR 2021-5062, Development of Regression Equations for the Estimation of the Magnitude and Frequency of Floods at Rural, Unregulated Gaged and Ungaged Streams in Puerto Rico Through Water Year 2017
RHODE ISLAND
Peak Flow & Regional skew (combined report)
SIR 2012-5109, Magnitude of Flood Flows for Selected Annual-Exceedance Probabilities in Rhode Island, through 2010, Version 1.1
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
SOUTH CAROLINA
Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2023-5065, Effects of Impoundments on Selected Flood-Frequency and Daily Mean Streamflow Characteristics in Georgia, South Carolina, and North Carolina
SIR 2023-5006, Magnitude and Frequency of Floods for Rural Streams in Georgia, South Carolina, and North Carolina, 2017—Results
SIR 2014-5030, Methods for Estimating the Magnitude and Frequency of Floods for Urban and Small, Rural Streams in Georgia, South Carolina, and North Carolina, 2011
SOUTH DAKOTA
Peak Flow
WRIR 98-4055, A Method for Estimating Magnitude and Frequency of Floods in South Dakota
TENNESSEE
Peak Flow
WRIR 84-4110, Flood Frequency and Storm Runoff of Urban Areas of Memphis and Shelby County, Tennessee
WRIR 84-4182, Synthesized flood frequency for small urban streams in Tennessee
WRIR 03-4176, Flood-Frequency Prediction Methods for Unregulated Streams of Tennessee, 2000
Updated peak flow report coming soon...
TEXAS
Peak Flow
SIR 2009-5087, Regression Equations for Estimation of Annual Peak-Streamflow Frequency for Undeveloped Watersheds in Texas Using an L-moment-Based, PRESS-Minimized, Residual-Adjusted Approach
Regional Skew
https://doi.org/10.18738/T8/SVLCOQ, Technique to estimate generalized skew coefficients of annual peak streamflow for natural watershed conditions in Texas, Oklahoma, and eastern New Mexico
UTAH
Peak Flow & Regional Skew (combined report)
SIR 2006-5306, Analysis of the Magnitude and Frequency of Peak Discharges for the Navajo Nation in Arizona, Utah, Colorado, and New Mexico
SIR 2007-5158, Methods for Estimating Magnitude and Frequency of Peak Flows for Natural Streams in Utah
VERMONT
Peak Flow
SIR 2014-5078, Estimation of Flood Discharges at Selected Annual Exceedance Probabilities for Unregulated, Rural Streams in Vermont
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
VIRGINIA
Peak Flow
SIR 2011-5144, Peak-Flow Characteristics of Virginia Streams
WASHINGTON
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5118, Magnitude, frequency, and trends of floods at gaged and ungaged sites in Washington, based on data through water year 2014 (ver 1.1, October 2016)
WEST VIRGINIA
Peak Flow
SIR 2010-5033, Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia
Regional Skew
OFR 2008-1304, Generalized Skew Coefficients of Annual Peak Flows for Rural, Unregulated Streams in West Virginia
WISCONSIN
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2022-5118, Estimating Flood Magnitude and Frequency for Unregulated Streams in Wisconsin
WYOMING
Peak Flow & Regional Skew (combined report)
WRIR 03-4107, Peak-Flow Characteristics of Wyoming Streams
Other
FS 2024-3035, June 2022 Floods in the Upper Yellowstone River Basin
Below are other science projects associated with flood frequency.
The 100-Year Flood
StreamStats: Streamflow Statistics and Spatial Analysis Tools for Water-Resources Applications
Flood Inundation Mapping (FIM) Program
Flood-frequency analysis provides information about the magnitude and frequency of floods based on records of annual maximum instantaneous peak discharges. Accurate flood-frequency estimates, created using consistent and uniformly applied methods, are a key component of any effective flood risk and management program. This is a list of current USGS flood frequency reports published by state.
NOTICE: Potential computational issues in the PeakFQ software continue to be investigated in collaboration with the U.S. Army Corps of Engineers (USACE). Refined user guidance and/or updated methodology documentation will be developed and made available, if needed.
For detailed information, please visit this page.
Flood Frequency Overview
Floods are dangerous natural hazards that can threaten lives, livelihoods, and property. Without information on flood risk, the planning, design, and management of infrastructure along rivers would be forced to proceed without quantitative scientific analysis. Flood-frequency analysis provides information about the magnitude and frequency of flood discharges based on records of annual maximum instantaneous peak discharges collected at streamgages. In essence, flood-frequency analysis is used to estimate the probability of flooding at specific river locations.
Accurate estimates of flood frequency and magnitude are a key component of any effective nationwide flood risk management and flood damage abatement program. In addition to accuracy, methods for estimating flood risk must be uniformly and consistently applied because management of the Nation’s water and related land resources is a collaborative effort involving multiple actors including most levels of government and the private sector.
To ensure consistency in flood-frequency analysis, multiple federal agencies have worked together to produce the Guidelines for Determining Flood Flow Frequency - Bulletin 17C, released in 2019. Updates include: adoption of a generalized representation of flood data that allows for interval and censored data types; a new method, called the Expected Moments Algorithm, which extends the method of moments so that it can accommodate interval data; a generalized approach to identification of low outliers in flood data; and an improved method for computing confidence intervals. Federal agencies are requested to use these Guidelines in all planning activities involving water and related land resources. State, local, and private organizations are encouraged to use these Guidelines to assure uniformity in the flood-frequency estimates that all agencies concerned with flood risk should use for Federal planning decisions.
For additional information on the basics of flood-frequency analysis, see also The 100-Year-Flood-It’s All About Chance (USGS General Information Product 106) and our 100-Year Flood webpage (USGS Water Science School).
USGS Reports: Flood Frequency and Regional Skew
Below is a list of the most recent flood frequency reports published by the USGS and organized by state. This list includes reports pertaining to regional skew, as well as regional annual exceedance probability equations for both peak flow and flood-duration flows. It will be updated as new reports are published.
As B17C recommends weighting the at-site skew with regional skew, this list provides the most current regional skew study for each state, which include both B17C recommended BGLS regional skew as well as other methodologies. If a B-GLS regional skew is not available, it is recommended that users consult with the USGS to determine the availability of alternate regional skew estimates. If no alternatives are available, then use the B17B map.
Reports which use the flood-frequency methods recommended in Bulletin 17C will be denoted with “B17C.”
For additional information, please contact your local Water Science Center or email gs_b17c@usgs.gov.
ALABAMA
Peak Flow
SIR 2007-5204, Magnitude and Frequency of Floods in Alabama, 2003
SIR 2010-2012, Magnitude and Frequency of Floods for Urban Streams in Alabama, 2007
B17C
SIR 2020-5032, Magnitude and Frequency of Floods in Alabama, 2015
ALASKA
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5024, Estimating flood magnitude and frequency at gaged and ungaged sites on streams in Alaska and conterminous basins in Canada, based on data through water year 2012
ARIZONA
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2014-5211, Methods for estimating magnitude and frequency of floods in Arizona, developed with unregulated and rural peak-flow data through water year 2010
B17C Flood-Duration Flows with B17C B-GLS Regional Skews
SIR 2014-5109, Methods for estimating magnitude and frequency of 1-, 3-, 7-, 15-, and 30-day flood-duration flows in Arizona
ARKANSAS
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5081, Methods for estimating annual exceedance probability discharges for streams in Arkansas, based on data through water year 2013
B17C
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
CALIFORNIA
B17C B-GLS Regional Skew
SIR 2010-5260, Regional skew for California, and flood frequency for selected sites in the Sacramento-San Joaquin River Basin, based on data through water year 2006
B17C Peak Flow
SIR 2012-5113, Methods for determining magnitude and frequency of floods in California, based on data through water year 2006
B17C Flood-Duration Flows with B17C B-GLS Regional Skews
SIR 2012-5130, Development of regional skews for selected flood durations for the Central Valley Region, California, based on data through water year 2008
COLORADO
B17C Peak Flow
SIR 2016-5099, Paleoflood investigations to improve peak-streamflow regional-regression equations for natural streamflow in eastern Colorado
Peak Flow
SIR 2009-5136, Regional Regression Equations for Estimation of Natural streamflow Statistics in Colorado
Updated peak flow/low flow/max flow/duration flow regression report coming soon...
CONNECTICUT
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
Peak Flow
SIR 2020-5054, Estimating Flood Magnitude and Frequency on Streams and Rivers in Connecticut, Based on Data Through Water Year 2015
DELAWARE
Peak Flow
SIR 2006-5146, Magnitude and Frequency of Floods on Nontidal Streams in Delaware
B17C
SIR 2022-5005, Peak-Flow and Low-Flow Magnitude Estimates at Defined Frequencies and Durations for Nontidal Streams in Delaware
GEORGIA
Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2023-5065, Effects of Impoundments on Selected Flood-Frequency and Daily Mean Streamflow Characteristics in Georgia, South Carolina, and North Carolina
SIR 2023-5006, Magnitude and Frequency of Floods for Rural Streams in Georgia, South Carolina, and North Carolina, 2017—Results
SIR 2014-5030, Methods for Estimating the Magnitude and Frequency of Floods for Urban and Small, Rural Streams in Georgia, South Carolina, and North Carolina, 2011
HAWAII
Peak Flow
SIR 2023-5014, Magnitude and Frequency of Floods on Kauaʻi, Oʻahu, Molokaʻi, Maui, and Hawaiʻi, State of Hawaiʻi, Based on Data through Water Year 2020
IDAHO
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5083, Estimating peak-flow frequency statistics for selected gaged and ungaged sites in naturally flowing streams and rivers in Idaho
ILLINOIS
Peak Flow
Research Report FHWA-ICT-23-014, Estimating Peak-flow Quantiles for Selected Annual Exceedance Probabilities in Illinois
FHWA-ICT-23-014, Estimating peak-flow quantiles for selected annual exceedance probabilities in Illinois
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2016-5050, Estimation of Peak Discharge Quantiles for Selected Annual Exceedance Probabilities in Northeastern Illinois
INDIANA
Peak Flow
Rao, A. R. Flood Frequency Relationships for Indiana. Publication FHWA/IN/JTRP-2005/18. Joint Transportation Research Program, Indiana Department of Transportation and Purdue University, West Lafayette, Indiana, 2006.
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
IOWA
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2013-5086, Methods for Estimating Annual Exceedance-Probability Discharges for Streams in Iowa, Based on Data through Water Year 2010
SIR 2015-5055, Comparisons of Estimates of Annual Exceedance-Probability Discharges for Small Drainage Basins in Iowa, Based on Data through Water Year 2013
KANSAS
Peak Flow & Regional Skew
WRIR 00-4079, Estimation of Peak Streamflows for Unregulated Streams in Kansas
SIR 2017-5063, Methods for estimating annual exceedance-probability streamflows for streams in Kansas based on data through water year 2015
KENTUCKY
Peak Flow & Regional Skew
WRIR 97-4219, Estimation of peak-discharge frequency of urban streams in Jefferson County, Kentucky
WRIR 03-4180, Estimating the Magnitude of Peak Flows for Streams in Kentucky for Selected Recurrence Intervals
LOUISIANA
Peak Flow
SIR 2024-5031, Magnitude and Frequency of Floods in the Coastal Plain Region of Louisiana, 2016
TR No. 60, (1998) Floods in Louisiana, Magnitude and Frequency, Fifth Edition. In progress (coming soon)
B17C
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
A Coastal Plains peakflow report is coming soon...
B17C B-GLS Regional Skew
Appendix of: SIR 2016-5081, Methods for estimating annual exceedance probability discharges for streams in Arkansas, based on data through water year 2013
MAINE
Peak Flow & Regional Skew
WRIR 99-4008, Estimating the Magnitude of Peak Flows for Streams in Maine for Selected Recurrence Intervals
SIR 2020-5092, Estimating Flood Magnitude and Frequency on Gaged and Ungaged Streams in Maine
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
MARYLAND
Peak Flow
Application of Hydrologic Methods in Maryland
MASSACHUSETTS
B17C Peak Flow
SIR 2016-5156, Magnitude of flood flows at selected annual exceedance probabilities for streams in Massachusetts
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
MICHIGAN
Peak Flow
WRIR 84-4207, Statistical Models for Estimating Flow Characteristics of Michigan Streams, 1984
MINNESOTA
Peak Flow
SIR 2023-5079, Techniques for Estimating the Magnitude and Frequency of Peak Flows on Small Streams in Minnesota, Excluding the Rainy River Basin, Based on Data Through Water Year 2019
B17C
SIR 2019-5012, Techniques for Estimating the Magnitude and Frequency of Peak Flows on Small Streams in the Binational U.S. and Canadian Lake of the Woods–Rainy River Basin Upstream from Kenora, Ontario, Canada, Based on Data through Water Year 2013
MISSISSIPPI
Peak Flow & Regional Skew (combined report)
SIR 2018-5148, Flood Frequency of Rural Streams in Mississippi, 2013
B17C
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
MISSOURI
B17C Peak Flow & B17C Regional Skew (combined report)
SIR 2014-5165, Methods for Estimating Annual Exceedance-Probability Discharges and Largest Recorded Floods for Unregulated Streams in Rural Missouri
SIR 2010-5073, Estimation of the Magnitude and Frequency of Floods in Urban Basins in Missouri
SIR 2021-5046, Magnitude and Frequency of Floods in the Alluvial Plain of the Lower Mississippi River, 2017
MONTANA
Peak Flow & Regional skew (combined report)
WRIR 2015-5019, Montana StreamStats
SIR 2020-5142, Regional Regression Equations Based on Channel-Width Characteristics to Estimate Peak-Flow Frequencies at Ungaged Sites in Montana Using Peak-Flow Frequency Data through Water Year 2011
Other
FS 2024-3035, June 2022 Floods in the Upper Yellowstone River Basin
NEBRASKA
Peak Flow & Regional skew (combined report)
WRIR 99-4032, Peak-Flow Frequency Relations and Evaluation of the Peak-Flow Gaging Network in Nebraska
NEVADA
Peak Flow & Regional skew (combined report)
WSP 2433 (1997), Methods for Estimating Magnitude and Frequency of Floods in the Southwestern United States
Update coming soon...
NEW HAMPSHIRE
Peak Flow
SIR 2008-5206, Estimation of Flood Discharges at Selected Recurrence Intervals for Streams in New Hampshire
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
NEW JERSEY
Peak Flow & Regional skew (combined report)
SIR 2009-5167, Methodology for Estimation of Flood Magnitude and Frequency for New Jersey Streams
NEW MEXICO
Peak Flow & Regional skew (combined report)
SIR 2008-5119, Analysis of the Magnitude and Frequency of Peak Discharge and Maximum Observed Peak Discharge in New Mexico and Surrounding Areas
WSP 2433, Methods for estimating magnitude and frequency of floods in the southwestern United States
SIR 2006-5306, Analysis of the Magnitude and Frequency of Peak Discharges for the Navajo Nation in Arizona, Utah, Colorado, and New Mexico
NEW YORK
Peak Flow
SIR 2006-5112, Magnitude and Frequency of Floods in New York
Regional Skew
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2021-5015, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of Eastern New York and Pennsylvania, Based on Data Through Water Year 2013
NORTH CAROLINA
Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2023-5065, Effects of Impoundments on Selected Flood-Frequency and Daily Mean Streamflow Characteristics in Georgia, South Carolina, and North Carolina
SIR 2023-5006, Magnitude and Frequency of Floods for Rural Streams in Georgia, South Carolina, and North Carolina, 2017—Results
NORTH DAKOTA
Peak Flow & Regional skew (combined report)
SIR 2015-5096, Regional regression equations to estimate peak-flow frequency at sites in North Dakota using data through 2009
OHIO
Peak Flow
WSP 2432, Estimation of peak-frequency relations, flood hydrographs, and volume-duration-frequency relations of ungaged small urban streams in Ohio
B17C
SIR 2019-5018, Flood-Frequency Estimates for Ohio Streamgages Based on Data through Water Year 2015 and Techniques for Estimating Flood-Frequency Characteristics of Rural, Unregulated Ohio Streams
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
OKLAHOMA
Peak Flow
SIR 2015-5134, Methods for estimating the magnitude and frequency of peak streamflows at ungaged sites in and near the Oklahoma Panhandle
B17C
SIR 2019-5043, Methods for Estimating the Magnitude and Frequency of Peak Streamflows for Unregulated Streams in Oklahoma Developed by Using Streamflow Data Through 2017
Regional Skew
SIR 2009-5135, Statistical Summaries of Streamflow in and near Oklahoma Through 2007
OREGON
Peak Flow & Regional skew (combined report)
SIR 2005-5116, Estimation of Peak Discharges for Rural, Unregulated Streams in Western Oregon
WSP 2433 (1997), Methods for Estimating Magnitude and Frequency of Floods in the Southwestern United States
B17C B-GLS Regional Skew
Appendix of: SIR 2016-5118, Magnitude, frequency, and trends of floods at gaged and ungaged sites in Washington, based on data through water year 2014 (ver 1.1, October 2016)
PENNSYLVANIA
Peak Flow
SIR 2008-5102, Regression Equations for Estimating Flood Flows at Selected Recurrence Intervals for Ungaged Streams in Pennsylvania
B17C
SIR 2019-5094, Development of Regression Equations for the Estimation of Flood Flows at Ungaged Streams in Pennsylvania
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2021-5015, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of Eastern New York and Pennsylvania, Based on Data Through Water Year 2013
PUERTO RICO
Peak Flow & B17C Regional skew (combined report)
SIR 2021-5062, Development of Regression Equations for the Estimation of the Magnitude and Frequency of Floods at Rural, Unregulated Gaged and Ungaged Streams in Puerto Rico Through Water Year 2017
RHODE ISLAND
Peak Flow & Regional skew (combined report)
SIR 2012-5109, Magnitude of Flood Flows for Selected Annual-Exceedance Probabilities in Rhode Island, through 2010, Version 1.1
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
SOUTH CAROLINA
Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2023-5065, Effects of Impoundments on Selected Flood-Frequency and Daily Mean Streamflow Characteristics in Georgia, South Carolina, and North Carolina
SIR 2023-5006, Magnitude and Frequency of Floods for Rural Streams in Georgia, South Carolina, and North Carolina, 2017—Results
SIR 2014-5030, Methods for Estimating the Magnitude and Frequency of Floods for Urban and Small, Rural Streams in Georgia, South Carolina, and North Carolina, 2011
SOUTH DAKOTA
Peak Flow
WRIR 98-4055, A Method for Estimating Magnitude and Frequency of Floods in South Dakota
TENNESSEE
Peak Flow
WRIR 84-4110, Flood Frequency and Storm Runoff of Urban Areas of Memphis and Shelby County, Tennessee
WRIR 84-4182, Synthesized flood frequency for small urban streams in Tennessee
WRIR 03-4176, Flood-Frequency Prediction Methods for Unregulated Streams of Tennessee, 2000
Updated peak flow report coming soon...
TEXAS
Peak Flow
SIR 2009-5087, Regression Equations for Estimation of Annual Peak-Streamflow Frequency for Undeveloped Watersheds in Texas Using an L-moment-Based, PRESS-Minimized, Residual-Adjusted Approach
Regional Skew
https://doi.org/10.18738/T8/SVLCOQ, Technique to estimate generalized skew coefficients of annual peak streamflow for natural watershed conditions in Texas, Oklahoma, and eastern New Mexico
UTAH
Peak Flow & Regional Skew (combined report)
SIR 2006-5306, Analysis of the Magnitude and Frequency of Peak Discharges for the Navajo Nation in Arizona, Utah, Colorado, and New Mexico
SIR 2007-5158, Methods for Estimating Magnitude and Frequency of Peak Flows for Natural Streams in Utah
VERMONT
Peak Flow
SIR 2014-5078, Estimation of Flood Discharges at Selected Annual Exceedance Probabilities for Unregulated, Rural Streams in Vermont
B17C B-GLS Regional Skew
SIR 2017-5037, Methods for estimating regional coefficient of skewness for unregulated streams in New England
VIRGINIA
Peak Flow
SIR 2011-5144, Peak-Flow Characteristics of Virginia Streams
WASHINGTON
B17C Peak Flow & B17C B-GLS Regional Skew (combined report)
SIR 2016-5118, Magnitude, frequency, and trends of floods at gaged and ungaged sites in Washington, based on data through water year 2014 (ver 1.1, October 2016)
WEST VIRGINIA
Peak Flow
SIR 2010-5033, Estimation of Flood-Frequency Discharges for Rural, Unregulated Streams in West Virginia
Regional Skew
OFR 2008-1304, Generalized Skew Coefficients of Annual Peak Flows for Rural, Unregulated Streams in West Virginia
WISCONSIN
B17C B-GLS Regional Skew
SIR 2019-5105, Methods for Estimating Regional Skewness of Annual Peak Flows in Parts of the Great Lakes and Ohio River Basins, Based on Data Through Water Year 2013
SIR 2022-5118, Estimating Flood Magnitude and Frequency for Unregulated Streams in Wisconsin
WYOMING
Peak Flow & Regional Skew (combined report)
WRIR 03-4107, Peak-Flow Characteristics of Wyoming Streams
Other
FS 2024-3035, June 2022 Floods in the Upper Yellowstone River Basin
Below are other science projects associated with flood frequency.