Water: Lakes
National Lakes Assessment Data
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.
Individual Files:
- Sampled Lakes Information (CSV) (957K) | Variable Description (TXT) (9K)
- Final Notes for Lake Data (PDF) (22 pp, 64K, About PDF)
- Basin Landuse Metrics (CSV) (300K) | Variable Description (TXT) (5K)
- Buffer Landuse Metrics (CSV) (267K) | Variable Description (TXT) (5K)
- Chemical Condition Estimates (CSV) (525K) | Variable Description (TXT) (4K)
- Mean Dissolved Oxygen Values (CSV) (31K) | Variable Description (TXT) (1K)
- Mean Dissolved Oxygen Condition Estimates (CSV) (358K) | Variable Description (TXT) (3K)
- Physical Habitat Index Values (CSV) (706K) | Variable Description (TXT) (6K)
- Physical Habitat Condition Estimates (CSV) (508K) | Variable Description (TXT) (4K)
- Physical Habitat Metrics - A (CSV) (1.5M) | Lake Physical Habitat Metrics - B (CSV) (1.7M) | Variable Description (TXT) (37K)
- Phytoplankton Soft Algae Count Data (CSV) (11.4MB) | Variable Description (TXT) (3K)
- Phytoplankton Diatom Count Data (CSV) (4.3M) | Variable Description (TXT) (3K)
- Phytoplankton Sample Information (CSV) (218K) | Variable Description (TXT) (2K)
- Plankton Observed over Expected Model Values - Analysis Data (CSV) (1.8K) | Variable Description (TXT) (1K)
- Plankton Observed over Expected Model Values - Valid Sites Used (CSV) (129K) | Variable Description (TXT) (2K)
- Plankton O over E Model Condition Estimates (CSV) (432K) | Variable Description (TXT) (4K)
- Profile Data (CSV) (868K) | Variable Description (TXT) (1K)
- Recreational Condition Estimates (CSV) (506K) | Variable Description (TXT) (4K)
- Secchi Disk Data (CSV) (59K) | Variable Description (TXT) (1K)
- "Sediment Diatom Count Data - Top and Bottom" data files removed because of data quality issues
- "Sediment Diatom Sample Information" data file removed because of diatom data quality issues
- "Sediment Diatom IBI Data and Condition Estimate" data files removed because of data quality issues
- "Sediment Diatom Inference Model, Data and Condition Estimate" data files removed because of data quality issues
- Trophic Condition Estimate (CSV) (510K) | Variable Description (TXT) (4K)
- Visual Assessment Data (CSV) (795K) | Variable Description (TXT) (7K)
- Water Quality Data (CSV) (854K) | Variable Description (TXT) (10K)
- Zooplankton Count Data (CSV) (6.6M) | Variable Description (TXT) (4K)
- Zooplankton Sampling Information (CSV) (203K) | Variable Description (TXT) (1K)
Geosptial Files:
- Basin Delineations (ZIP) (17.4M)
- Sample Frame Polygons (ZIP) (M)