The National Lakes Assessment (NLA) is a statistical survey of the condition of our nation's lakes, ponds, and reservoirs. It is designed to provide information on the extent of lakes that support healthy biological condition and recreation, estimate how widespread major stressors are that impact lake quality, and provide insight into whether lakes nationwide are getting cleaner. This dataset is an archived (zipped) file comprised of chemical, physical and biological files used in developing the NLA 2017 report. Sampling was conducted in the summer of 2017 at approximately 1000 sites in the conterminous U.S. Sites were selected using a statistical survey (probabilistic) design. The files include water chemistry, profile data, benthic macroinvertebrates, physical habitat, landscape metrics, phytoplankton data, secchi depth, data, tropic status, zooplankton, etc. Users are encouraged to visit the NARS data webpage for updates to data files (e.g., for example updated zooplankton files) and data from other surveys. https://www.epa.gov/national-aquatic-resource-surveys/data-national-aquatic-resource-surveys Citation for the NLA 2017 archived data: U.S. Environmental Protection Agency. National Aquatic Resource Surveys. National Lakes Assessment 2017 Report. Archived Data. (INSERT data and metadata files used). Available from U.S. EPA web page: https://www.epa.gov/national-aquatic-resource-surveys/reports-and-data-national-lakes-assessment-2017. DOI: 10.23719/1529585 EPA encourages users who are publishing subsets of the data (say as part of a journal article publication) to include the above citation. EPA also encourages users of the data to include the following acknowledgement: “The National Lakes Assessment 2017 data were a result of the collective efforts of dedicated field crews, laboratory staff, data management and quality control staff, analysts and many others from EPA, states, tribes, federal agencies, universities, and other organizations. Please contact nars-hq@epa.gov with any questions.” Additional information: NLA is part of the National Aquatic Resource Surveys, an EPA/State/Tribal partnership. The National Aquatic Resource Surveys (NARS) are statistical surveys designed to assess the status of and changes in quality of the nation’s coastal waters, lakes and reservoirs, rivers and streams, and wetlands. Using sample sites selected at random, these surveys provide a snapshot of the overall condition of the nation’s water. Because the surveys use standardized field and lab methods, we can compare results from different parts of the country and between years. Citation information for this dataset can be found in Data.gov's References section.

The provided link will take users to all the data and metadata used in this project. This dataset is associated with the following publication: Angradi, T., P. Ringold, and K. Hall. Water clarity measures as indicators of recreational benefits provided by U.S. lakes: Swimming and aesthetics. ECOLOGICAL INDICATORS. Elsevier Science Ltd, New York, NY, USA, 93: 1005-1019, (2018).

The provided link will take users to all the data and metadata used in this project. This dataset is associated with the following publication: Angradi, T., P. Ringold, and K. Hall. Water clarity measures as indicators of recreational benefits provided by U.S. lakes: Swimming and aesthetics. ECOLOGICAL INDICATORS. Elsevier Science Ltd, New York, NY, USA, 93: 1005-1019, (2018).

National Lakes Assessment 2007 Datafiles for Report “National Lakes Assessment: A Collaborative Survey of the Nation’s Lakes”: The National Lakes Assessment (NLA) is a statistical survey of the condition of our nation's lakes, ponds, and reservoirs. It is designed to provide information on the extent of lakes that support healthy biological condition and recreation, estimate how widespread major stressors are that impact lake quality, and provide insight into whether lakes nationwide are getting cleaner. The first NLA was conducted in 2007. This dataset is an archived (zipped) file comprised of chemical, physical and biological files used in developing the NLA report. Sampling was conducted in the summer of 2007 at approximately 1000 sites in the conterminous U.S. Sites were selected using a statistical survey (probabilistic) design. The files include water chemistry, profile data, benthic macroinvertebrates, physical habitat, landscape metrics, phytoplankton data, secchi depth, data, tropic status, water isotopes, zooplankton, etc. Users are encouraged to visit the NARS data webpage for potential updates to data files and data from other surveys. https://www.epa.gov/national-aquatic-resource-surveys/data-national-aquatic-resource-surveys Citation for the NLA 2007 archived data: U.S. Environmental Protection Agency. National Aquatic Resource Surveys. National Lakes Assessment 2007 Report. Archived Data. (INSERT data and metadata files used). Available from U.S. EPA web page: https://www.epa.gov/national-aquatic-resource-surveys/national-lakes-assessment-2007-report. DOI: 10.23719/1529550 EPA encourages users who are publishing subsets of the data (say as part of a journal article publication) to include the above citation. EPA also encourages users of the data to include the following acknowledgement: “The National Lakes Assessment 2007 data were a result of the collective efforts of dedicated field crews, laboratory staff, data management and quality control staff, analysts and many others from EPA, states, tribes, federal agencies, universities, and other organizations. Please contact nars-hq@epa.gov with any questions.” Additional information: NLA is part of the National Aquatic Resource Surveys, an EPA/State/Tribal partnership. The National Aquatic Resource Surveys (NARS) are statistical surveys designed to assess the status of and changes in quality of the nation’s coastal waters, lakes and reservoirs, rivers and streams, and wetlands. Using sample sites selected at random, these surveys provide a snapshot of the overall condition of the nation’s water. Because the surveys use standardized field and lab methods, we can compare results from different parts of the country and between years. Citation information for this dataset can be found in Data.gov's References section.

National Lakes Assessment 2012 Datafiles for Report “National Lakes Assessment 2012: A Collaborative Survey of lakes in the United States”: The National Lakes Assessment (NLA) is a statistical survey of the condition of our nation's lakes, ponds, and reservoirs. It is designed to provide information on the extent of lakes that support healthy biological condition and recreation, estimate how widespread major stressors are that impact lake quality, and provide insight into whether lakes nationwide are getting cleaner. This dataset is an archived (zipped) file comprised of chemical, physical and biological files used in developing the NLA 2012 report. Sampling was conducted in the summer of 2012 at approximately 1000 sites in the conterminous U.S. Sites were selected using a statistical survey (probabilistic) design. The files include water chemistry, profile data, benthic macroinvertebrates, physical habitat, landscape metrics, phytoplankton data, secchi depth, data, tropic status, zooplankton, etc. Users are encouraged to visit the NARS data webpage for updates to data files (e.g., for example updated zooplankton files) and data from other surveys. https://www.epa.gov/national-aquatic-resource-surveys/data-national-aquatic-resource-surveys Citation for the NLA 2012 archived data: U.S. Environmental Protection Agency. National Aquatic Resource Surveys. National Lakes Assessment 2012 Report. Archived Data. (INSERT data and metadata files used). Available from U.S. EPA web page: https://www.epa.gov/national-aquatic-resource-surveys/national-results-and-regional-highlights-national-lakes. DOI: 10.23719/1529584 EPA encourages users who are publishing subsets of the data (say as part of a journal article publication) to include the above citation. EPA also encourages users of the data to include the following acknowledgement: “The National Lakes Assessment 2012 data were a result of the collective efforts of dedicated field crews, laboratory staff, data management and quality control staff, analysts and many others from EPA, states, tribes, federal agencies, universities, and other organizations. Please contact nars-hq@epa.gov with any questions.” Additional information: NLA is part of the National Aquatic Resource Surveys, an EPA/State/Tribal partnership. The National Aquatic Resource Surveys (NARS) are statistical surveys designed to assess the status of and changes in quality of the nation’s coastal waters, lakes and reservoirs, rivers and streams, and wetlands. Using sample sites selected at random, these surveys provide a snapshot of the overall condition of the nation’s water. Because the surveys use standardized field and lab methods, we can compare results from different parts of the country and between years. Citation information for this dataset can be found in Data.gov's References section.

National Lakes Assessment 2012 Datafiles for Report “National Lakes Assessment 2012: A Collaborative Survey of lakes in the United States”: The National Lakes Assessment (NLA) is a statistical survey of the condition of our nation's lakes, ponds, and reservoirs. It is designed to provide information on the extent of lakes that support healthy biological condition and recreation, estimate how widespread major stressors are that impact lake quality, and provide insight into whether lakes nationwide are getting cleaner. This dataset is an archived (zipped) file comprised of chemical, physical and biological files used in developing the NLA 2012 report. Sampling was conducted in the summer of 2012 at approximately 1000 sites in the conterminous U.S. Sites were selected using a statistical survey (probabilistic) design. The files include water chemistry, profile data, benthic macroinvertebrates, physical habitat, landscape metrics, phytoplankton data, secchi depth, data, tropic status, zooplankton, etc. Users are encouraged to visit the NARS data webpage for updates to data files (e.g., for example updated zooplankton files) and data from other surveys. https://www.epa.gov/national-aquatic-resource-surveys/data-national-aquatic-resource-surveys Citation for the NLA 2012 archived data: U.S. Environmental Protection Agency. National Aquatic Resource Surveys. National Lakes Assessment 2012 Report. Archived Data. (INSERT data and metadata files used). Available from U.S. EPA web page: https://www.epa.gov/national-aquatic-resource-surveys/national-results-and-regional-highlights-national-lakes. DOI: 10.23719/1529584 EPA encourages users who are publishing subsets of the data (say as part of a journal article publication) to include the above citation. EPA also encourages users of the data to include the following acknowledgement: “The National Lakes Assessment 2012 data were a result of the collective efforts of dedicated field crews, laboratory staff, data management and quality control staff, analysts and many others from EPA, states, tribes, federal agencies, universities, and other organizations. Please contact nars-hq@epa.gov with any questions.” Additional information: NLA is part of the National Aquatic Resource Surveys, an EPA/State/Tribal partnership. The National Aquatic Resource Surveys (NARS) are statistical surveys designed to assess the status of and changes in quality of the nation’s coastal waters, lakes and reservoirs, rivers and streams, and wetlands. Using sample sites selected at random, these surveys provide a snapshot of the overall condition of the nation’s water. Because the surveys use standardized field and lab methods, we can compare results from different parts of the country and between years. Citation information for this dataset can be found in Data.gov's References section.

The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S. Environmental Protection Agency (EPA) worked with states and tribes to conduct the assessment in 2007. Data for each parameter sampled in the National Lakes Assessment (NLA) are available for downloading in a series of files as comma separated values (*.csv). Each *.csv data file has a companion text file (*.txt) that lists a dataset label and individual descriptions for each variable. Users should view the *.txt files first to help guide their understanding and use of the data.

The National Aquatic Resource Surveys National Lakes Assessment data contain lake conductivity information at lakes in the contiguous United States. The LakeCat data contain watershed metrics for lakes in the contiguous United States. This dataset is associated with the following publication: Dumelle, M., J. Ver Hoef, A. Handler, R. Hill, M. Higham, and A. Olsen. Modeling lake conductivity in the contiguous United States using spatial indexing for big spatial data. Spatial Statistics. Elsevier Ltd, Oxford, UK, 59: 100808, (2024).

Chloride data used to assess trends over time, using both USGS data for trends in loads and USEPA NRSA data used to assess trends in concentrations. Citation information for this dataset can be found in the EDG's Metadata Reference Information section and Data.gov's References section.

환경부 국립환경과학원에서 운영하고 있는 물환경정보시스템의 수질오염총량 관리제도 중 지류총량 면적 비율 분석 결과에 관한 데이터를 제공합니다.이 자료는 본류와 지류의 유역 면적을 비교하여 각 지류가 본류 전체에서 차지하는 면적 비율을 산정하고, 유역별 부하량 산정 시 면적 가중치를 반영하기 위해 구축되었습니다.데이터에는 지류총량 코드, 지류총량명, 지류 면적, 면적비율 분자값, 본류 코드, 본류명, 본류 면적, 본류 면적비율 분모값, 면적비율 등이 포함되어 있습니다.이 데이터는 수계별 하천 구조를 면적 기반으로 비교함으로써, 총량관리 단계별 하천유역의 공간적 분포와 상대적 중요도를 분석하는 데 활용됩니다.또한 유역 단위의 부하량 배분, 수질개선 우선순위 설정, 상·하류 간 영향도 분석 등 다양한 수문·수질 해석의 참고자료로 이용됩니다.