Ken Fritz
U.S. Environmental Protection Agency;Office of Water | Research Ecologist
Recent Activity
ABSTRACT:
Drying has a major impact on pattern and process in streams, particularly in small or headwater streams. Such streams that dry recurrently are called non-perennial streams and represent most of the channel length across river networks. In spite of their prevalence, non-perennial streams are vastly underrepresented in existing stream gaging networks and in maps and hydrographic datasets. However, diverse and spatially extensive datasets of surface water presence observations exist as well as recently developed mobile applications that could help fill the data gap in characterizing the spatial extent of non-perennial streams. Hydrological data from perennial and non-perennial reaches were compiled from a series of studies on headwater streams to expand available data for mapping and modeling efforts in the United States. Hydrologic data within this compilation include visually recorded observations of hydrological status (dry, isolated pools, interstitial flow, and continuous surface flow), point measurements of discharge (cubic meters per second), and logger-based measurements for the timing and duration of streamflow and drying. These data were compiled across a series of studies on headwater streams (drainage area ~2.6 km2 or less) and were used to characterize their hydrology. Hydrologic data within this compilation are organized into files based on type of hydrologic data and study area. The types of hydrologic data include visually recorded observations of hydrological status (dry, isolated pools, interstitial flow, and continuous surface flow), point measurements of discharge (cubic meters per second), and logger-based measurements for the timing and duration of streamflow and drying. The study areas included in the compilation include headwater streams in Kentucky (Robinson Forest), Illinois (Shawnee National Forest), Indiana (Hoosier National Forest), New Hampshire (Dodge Brook), New York (Balsam Lake Mountain), North Dakota (Pipestem), Ohio (Congress Run, Edgewood Preserve, Edge of Appalachia, Wayne National Forest), South Carolina (Carolina Sandhills, Sugarloaf Mountain, Sumter National Forest Enoree and Long Cane Districts), Tennessee (Big Ridge), Vermont (Hinesburg), Washington (Mt. Baker-Snoqualmie), and West Virginia (Coopers Rock). A more detailed description of the data files are included within the Data description.docx and Data Dictionary for logger data compilation.xlsx files. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1532528
ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Northeast (NE) and Southeast (SE) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the NE and the Beta SDAM for the SE. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the Beta SDAMs: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1528743
ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Great Plains (GP) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the GP. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the GP Beta SDAM: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1527943
ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Western Mountains (WM) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the WM. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the WM Beta SDAM: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1526066
ABSTRACT:
Hydrological, biological, and geomorphological dataset collected from the Pacific Northwest (PNW = Oregon, Idaho, and Washington) used to develop the Oregon (OR) Streamflow Duration Assessment Method (SDAM) and the PN SDAM. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the OR and PNW SDAMs: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt
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ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Arid West (AW) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the AW. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the AW Beta SDAM: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1523371

ABSTRACT:
Hydrological, biological, and geomorphological dataset collected from the Pacific Northwest (PNW = Oregon, Idaho, and Washington) used to develop the Oregon (OR) Streamflow Duration Assessment Method (SDAM) and the PN SDAM. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the OR and PNW SDAMs: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt

ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Western Mountains (WM) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the WM. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the WM Beta SDAM: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1526066

ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Great Plains (GP) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the GP. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the GP Beta SDAM: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1527943

ABSTRACT:
Hydrological, biological, geomorphological, and geospatial datasets collected from the Northeast (NE) and Southeast (SE) used to develop the Beta Streamflow Duration Assessment Method (SDAM) for the NE and the Beta SDAM for the SE. SDAMs are rapid, reach-scale indices or models that use physical and/or biological indicators to predict flow duration class. Three flow duration classes are used in the Beta SDAMs: perennial, intermittent, and ephemeral. Perennial reaches have continuous surface flow and do not experience drying outside of extreme drought. Intermittent reaches have continuous surface flow for part of the year that is sustained by snowmelt and/or groundwater. Ephemeral reaches have surface flow only during and immediately following precipitation or snowmelt. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1528743

Created: Sept. 30, 2025, 6:34 p.m.
Authors: Fritz, Ken
ABSTRACT:
Drying has a major impact on pattern and process in streams, particularly in small or headwater streams. Such streams that dry recurrently are called non-perennial streams and represent most of the channel length across river networks. In spite of their prevalence, non-perennial streams are vastly underrepresented in existing stream gaging networks and in maps and hydrographic datasets. However, diverse and spatially extensive datasets of surface water presence observations exist as well as recently developed mobile applications that could help fill the data gap in characterizing the spatial extent of non-perennial streams. Hydrological data from perennial and non-perennial reaches were compiled from a series of studies on headwater streams to expand available data for mapping and modeling efforts in the United States. Hydrologic data within this compilation include visually recorded observations of hydrological status (dry, isolated pools, interstitial flow, and continuous surface flow), point measurements of discharge (cubic meters per second), and logger-based measurements for the timing and duration of streamflow and drying. These data were compiled across a series of studies on headwater streams (drainage area ~2.6 km2 or less) and were used to characterize their hydrology. Hydrologic data within this compilation are organized into files based on type of hydrologic data and study area. The types of hydrologic data include visually recorded observations of hydrological status (dry, isolated pools, interstitial flow, and continuous surface flow), point measurements of discharge (cubic meters per second), and logger-based measurements for the timing and duration of streamflow and drying. The study areas included in the compilation include headwater streams in Kentucky (Robinson Forest), Illinois (Shawnee National Forest), Indiana (Hoosier National Forest), New Hampshire (Dodge Brook), New York (Balsam Lake Mountain), North Dakota (Pipestem), Ohio (Congress Run, Edgewood Preserve, Edge of Appalachia, Wayne National Forest), South Carolina (Carolina Sandhills, Sugarloaf Mountain, Sumter National Forest Enoree and Long Cane Districts), Tennessee (Big Ridge), Vermont (Hinesburg), Washington (Mt. Baker-Snoqualmie), and West Virginia (Coopers Rock). A more detailed description of the data files are included within the Data description.docx and Data Dictionary for logger data compilation.xlsx files. These datasets are also located at the United States Environmental Protection Agency data repository at: https://doi.org/10.23719/1532528