Nancy is an Hydrologist with the Colorado Water Science Center, Denver, Colorado
Science and Products
Lower Yampa Streamflow and Sediment Modeling
Water from the Yampa River basin continues to be sought for a number of municipal, industrial, and energy uses. Water development in the Yampa River basin will alter the streamflow regime and, consequently, will lead to changes in the transport and storage of suspended and bedload sediment. Changes in the Yampa River sediment budget could lead to changes in channel geometry, riparian vegetation...
Upper Yampa Watershed Water-Quality Data
The Upper Yampa River Watershed (UYRW) drains approximately 1,798 square miles west of the Continental Divide in northwestern Colorado. The Upper Yampa River Watershed includes the Yampa River Basin upstream from Elkhead Creek and the Elkhead Creek Basin and primarily is in Routt County. The city of Steamboat Springs and the towns of Hayden, Oak Creek, and Yampa are in the watershed. The Yampa...
Aquatic communities and associated water chemistry in the St. Vrain River near the City of Longmont wastewater-treatment plant
The St. Vrain River watershed in northeastern Colorado has experienced rapid urban growth over the last two decades. Population growth has led to increased volumes being treated at wastewater-treatment plants (WWTPs) in the basin. In the last two decades, in-stream restoration efforts and new treatment technologies have been implemented by the City of Longmont, with the goal of improving water...
Blue River Water-Quality Data
The Blue River drains approximately 680 square miles west of the Continental Divide in central Colorado before flowing northward into the Colorado River near Kremmling, Colorado. The Blue River watershed (BRW) is almost entirely located in Summit County and includes the towns of Breckenridge, Dillon, Frisco, Montezuma, and Silverthorne. Dillon Reservoir and Green Mountain Reservoir are major water...
Water-Quality Monitoring of the Vallecito Reservoir Watershed
The water quality of the Vallecito Reservoir watershed in southwestern Colorado was initially studied by the U.S. Geological Survey (USGS) during July 1996 to July 1997, in cooperation with the Pine River Irrigation District, to assess the suitability of the reservoir as a potential source of drinking water (Ranalli and Evans, 1999). As a result of this study, in December 1997 a group of residents...
Effects of increasing urbanization on ground- and surface-water resources in the Fraser River watershed
The USGS has assessed the effects of increasing urbanization on ground- and surface-water resources in the Fraser River watershed. The population of Grand County increased 93 percent between the years of 1970 and 1990. The majority of the new development in the watershed will rely on ground water and individual septic disposal systems (ISDS's). This study has assessed the potential effects of ISDS...
Filter Total Items: 20
Characterization of and temporal changes in groundwater quality of the Upper Black Squirrel Creek Basin, El Paso County, Colorado, 2018–20
In 2018–20, the U.S. Geological Survey, in cooperation with Upper Black Squirrel Creek Ground Water Management District, sampled 48 wells for Phase III of a multiphase plan investigating groundwater quality in the alluvial aquifer of the Upper Black Squirrel Creek Basin (UBSB), El Paso County, Colorado. Results for samples collected from October to December each year were used to assess spatial an
Characterization of water-resource threats and needs for U.S. Fish and Wildlife Service National Wildlife Refuges in the Legacy Mountain-Prairie Region, 2020
The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service (FWS), began a study in 2019 to complete the compilation and quality assurance of water-resource threats and needs data for the 117 National Wildlife Refuges (NWRs) in the FWS Legacy Mountain-Prairie Region (LMPR) and to characterize the water-resource threats and needs of each refuge and of the LMPR itself. The LMP
Development of an approach for integrating components of the U.S. Geological Survey Biomonitoring of Environmental Status and Trends (BEST) and National Stream Quantity Accounting Network (NASQAN) programs for large U.S. rivers
A national-scale framework for monitoring environmental contaminants in fish and effects of contaminant exposure on fish in large U.S. rivers has been proposed by the Biomonitoring of Environmental Status and Trends (BEST) Program of the U.S. Geological Survey (USGS). The framework shares many features and objectives with the USGS National Stream Quantity Accounting Network (NASQAN) Program, which
Hydrogeologic characterization, groundwater chemistry, and vulnerability assessment, Ute Mountain Ute Reservation, Colorado and Utah
The U.S. Geological Survey, in cooperation with the Ute Mountain Ute Tribe (UMUT), initiated a study in 2016 to increase understanding of the hydrogeology and chemistry of groundwater within select areas of the Ute Mountain Ute Reservation (UMUR) in Colorado and Utah, identify vulnerabilities to the system and other natural resources, and outline information needs to aid in the understanding and p
Streamflow and selenium loads during synoptic sampling of the Gunnison River and its tributaries near Delta, Colorado, November 2015
In response to the need for more information about selenium (Se) sources and transport, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, completed a study that characterized Se loads in a reach of the Gunnison River between Delta and Grand Junction, Colo. This report identifies where possible dissolved Se loading is occurring in a study reach in the Lower Gunn
The quality of our Nation's waters: water quality in the Denver Basin aquifer system, Colorado, 2003-05
Availability and sustainability of groundwater in the Denver Basin aquifer system depend on water quantity and water quality. The Denver Basin aquifer system underlies about 7,000 square miles of the Great Plains in eastern Colorado and is the primary or sole source of water for domestic and public supply in many areas of the basin. Use of groundwater from the Denver Basin sandstone aquifers has b
Analysis of water quality in the Blue River watershed, Colorado, 1984 through 2007
Water quality of streams, reservoirs, and groundwater in the Blue River watershed in the central Rocky Mountains of Colorado has been affected by local geologic conditions, historical hard-rock metal mining, and recent urban development. With these considerations, the U.S. Geological Survey, in cooperation with the Summit Water Quality Committee, conducted a study to compile historical water-quali
Quality of groundwater in the Denver Basin aquifer system, Colorado, 2003-5
Groundwater resources from alluvial and bedrock aquifers of the Denver Basin are critical for municipal, domestic, and agricultural uses in Colorado along the eastern front of the Rocky Mountains. Rapid and widespread urban development, primarily along the western boundary of the Denver Basin, has approximately doubled the population since about 1970, and much of the population depends on groundwa
Water-quality assessment and macroinvertebrate data for the Upper Yampa River watershed, Colorado, 1975 through 2009
A study was initiated in 2009 by the U.S. Geological Survey (USGS), in cooperation with Routt County, the Colorado Water Conservation Board, and the City of Steamboat Springs, to compile and analyze historic water-quality data and assess water-quality conditions in the Upper Yampa River watershed (UYRW) in northwestern Colorado. Water-quality data for samples collected by federal, state, and local
Data on mercury in water, bed sediment, and fish from streams across the United States, 1998-2005
The U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and Toxic Substances Hydrology Programs conducted the National Mercury Pilot Study in 1998 to examine relations of mercury (Hg) in water, bed sediment and fish in streams across the United States, including Alaska and Hawaii. Water and bed-sediment samples were analyzed for total Hg (THg), methylmercury (MeHg), and other c
Mercury in fish, bed sediment, and water from streams across the United States, 1998-2005
Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg)
Salinity trends in the upper Colorado River basin upstream from the Grand Valley Salinity Control Unit, Colorado, 1986-2003
In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or "units" of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in wes
Science and Products
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Lower Yampa Streamflow and Sediment Modeling
Water from the Yampa River basin continues to be sought for a number of municipal, industrial, and energy uses. Water development in the Yampa River basin will alter the streamflow regime and, consequently, will lead to changes in the transport and storage of suspended and bedload sediment. Changes in the Yampa River sediment budget could lead to changes in channel geometry, riparian vegetation...Upper Yampa Watershed Water-Quality Data
The Upper Yampa River Watershed (UYRW) drains approximately 1,798 square miles west of the Continental Divide in northwestern Colorado. The Upper Yampa River Watershed includes the Yampa River Basin upstream from Elkhead Creek and the Elkhead Creek Basin and primarily is in Routt County. The city of Steamboat Springs and the towns of Hayden, Oak Creek, and Yampa are in the watershed. The Yampa...Aquatic communities and associated water chemistry in the St. Vrain River near the City of Longmont wastewater-treatment plant
The St. Vrain River watershed in northeastern Colorado has experienced rapid urban growth over the last two decades. Population growth has led to increased volumes being treated at wastewater-treatment plants (WWTPs) in the basin. In the last two decades, in-stream restoration efforts and new treatment technologies have been implemented by the City of Longmont, with the goal of improving water...Blue River Water-Quality Data
The Blue River drains approximately 680 square miles west of the Continental Divide in central Colorado before flowing northward into the Colorado River near Kremmling, Colorado. The Blue River watershed (BRW) is almost entirely located in Summit County and includes the towns of Breckenridge, Dillon, Frisco, Montezuma, and Silverthorne. Dillon Reservoir and Green Mountain Reservoir are major water...Water-Quality Monitoring of the Vallecito Reservoir Watershed
The water quality of the Vallecito Reservoir watershed in southwestern Colorado was initially studied by the U.S. Geological Survey (USGS) during July 1996 to July 1997, in cooperation with the Pine River Irrigation District, to assess the suitability of the reservoir as a potential source of drinking water (Ranalli and Evans, 1999). As a result of this study, in December 1997 a group of residents...Effects of increasing urbanization on ground- and surface-water resources in the Fraser River watershed
The USGS has assessed the effects of increasing urbanization on ground- and surface-water resources in the Fraser River watershed. The population of Grand County increased 93 percent between the years of 1970 and 1990. The majority of the new development in the watershed will rely on ground water and individual septic disposal systems (ISDS's). This study has assessed the potential effects of ISDS... - Publications
Filter Total Items: 20
Characterization of and temporal changes in groundwater quality of the Upper Black Squirrel Creek Basin, El Paso County, Colorado, 2018–20
In 2018–20, the U.S. Geological Survey, in cooperation with Upper Black Squirrel Creek Ground Water Management District, sampled 48 wells for Phase III of a multiphase plan investigating groundwater quality in the alluvial aquifer of the Upper Black Squirrel Creek Basin (UBSB), El Paso County, Colorado. Results for samples collected from October to December each year were used to assess spatial anCharacterization of water-resource threats and needs for U.S. Fish and Wildlife Service National Wildlife Refuges in the Legacy Mountain-Prairie Region, 2020
The U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service (FWS), began a study in 2019 to complete the compilation and quality assurance of water-resource threats and needs data for the 117 National Wildlife Refuges (NWRs) in the FWS Legacy Mountain-Prairie Region (LMPR) and to characterize the water-resource threats and needs of each refuge and of the LMPR itself. The LMPDevelopment of an approach for integrating components of the U.S. Geological Survey Biomonitoring of Environmental Status and Trends (BEST) and National Stream Quantity Accounting Network (NASQAN) programs for large U.S. rivers
A national-scale framework for monitoring environmental contaminants in fish and effects of contaminant exposure on fish in large U.S. rivers has been proposed by the Biomonitoring of Environmental Status and Trends (BEST) Program of the U.S. Geological Survey (USGS). The framework shares many features and objectives with the USGS National Stream Quantity Accounting Network (NASQAN) Program, whichHydrogeologic characterization, groundwater chemistry, and vulnerability assessment, Ute Mountain Ute Reservation, Colorado and Utah
The U.S. Geological Survey, in cooperation with the Ute Mountain Ute Tribe (UMUT), initiated a study in 2016 to increase understanding of the hydrogeology and chemistry of groundwater within select areas of the Ute Mountain Ute Reservation (UMUR) in Colorado and Utah, identify vulnerabilities to the system and other natural resources, and outline information needs to aid in the understanding and pStreamflow and selenium loads during synoptic sampling of the Gunnison River and its tributaries near Delta, Colorado, November 2015
In response to the need for more information about selenium (Se) sources and transport, the U.S. Geological Survey, in cooperation with the Colorado Water Conservation Board, completed a study that characterized Se loads in a reach of the Gunnison River between Delta and Grand Junction, Colo. This report identifies where possible dissolved Se loading is occurring in a study reach in the Lower GunnThe quality of our Nation's waters: water quality in the Denver Basin aquifer system, Colorado, 2003-05
Availability and sustainability of groundwater in the Denver Basin aquifer system depend on water quantity and water quality. The Denver Basin aquifer system underlies about 7,000 square miles of the Great Plains in eastern Colorado and is the primary or sole source of water for domestic and public supply in many areas of the basin. Use of groundwater from the Denver Basin sandstone aquifers has bAnalysis of water quality in the Blue River watershed, Colorado, 1984 through 2007
Water quality of streams, reservoirs, and groundwater in the Blue River watershed in the central Rocky Mountains of Colorado has been affected by local geologic conditions, historical hard-rock metal mining, and recent urban development. With these considerations, the U.S. Geological Survey, in cooperation with the Summit Water Quality Committee, conducted a study to compile historical water-qualiQuality of groundwater in the Denver Basin aquifer system, Colorado, 2003-5
Groundwater resources from alluvial and bedrock aquifers of the Denver Basin are critical for municipal, domestic, and agricultural uses in Colorado along the eastern front of the Rocky Mountains. Rapid and widespread urban development, primarily along the western boundary of the Denver Basin, has approximately doubled the population since about 1970, and much of the population depends on groundwaWater-quality assessment and macroinvertebrate data for the Upper Yampa River watershed, Colorado, 1975 through 2009
A study was initiated in 2009 by the U.S. Geological Survey (USGS), in cooperation with Routt County, the Colorado Water Conservation Board, and the City of Steamboat Springs, to compile and analyze historic water-quality data and assess water-quality conditions in the Upper Yampa River watershed (UYRW) in northwestern Colorado. Water-quality data for samples collected by federal, state, and localData on mercury in water, bed sediment, and fish from streams across the United States, 1998-2005
The U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) and Toxic Substances Hydrology Programs conducted the National Mercury Pilot Study in 1998 to examine relations of mercury (Hg) in water, bed sediment and fish in streams across the United States, including Alaska and Hawaii. Water and bed-sediment samples were analyzed for total Hg (THg), methylmercury (MeHg), and other cMercury in fish, bed sediment, and water from streams across the United States, 1998-2005
Mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury (MeHg) bioaccumulation. Sampled settings include stream basins that were agricultural, urbanized, undeveloped (forested, grassland, shrubland, and wetland land cover), and mined (for gold and Hg)Salinity trends in the upper Colorado River basin upstream from the Grand Valley Salinity Control Unit, Colorado, 1986-2003
In 1974, the Colorado River Basin Salinity Control Act was passed into law. This law was enacted to address concerns regarding the salinity content of the Colorado River. The law authorized various construction projects in selected areas or "units" of the Colorado River Basin intended to reduce the salinity load in the Colorado River. One such area was the Grand Valley Salinity Control Unit in wes - Multimedia