Nitrogen And Phosphorus Budgets For U.S. Streams And Lakes

2.64 million stream segments and 378,088 lakes have watershed and local catchment nutrient budgets for nitrogen and phosphorus. The U.S. Environmental Protection Agency created this dataset by integrating its National Nutrient Inventory with the StreamCat database. It provides a 30-year annual time-series from 1987 to 2017.

Use Cases

• Modeling legacy_agricultural_surplus for phosphorus to predict long-term water quality impacts in specific watersheds.
• Analyzing trends in anthropogenic_inputs and natural_inputs of nitrogen over the 30-year time-series to evaluate policy effectiveness.
• Correlating agricultural_surplus metrics with downstream water quality measurements in lake catchments.
• Spatially mapping major nutrient outputs across ~2.64 million stream segments to identify regional pollution hotspots.

Strengths

• Covers ~2.64 million stream segments and 378,088 lakes, providing national-scale spatial detail.
• Includes a 30-year annual time-series (1987-2017) for longitudinal analysis.
• Derived from the authoritative U.S. EPA National Nutrient Inventory and StreamCat database, with publicly available workflow components for replication.

Limitations

• Nutrient budgets are modeled via downscaling (dasymetric apportionment) and accumulation, not direct measurements, introducing potential estimation error.
• Temporal coverage ends in 2017, which may not reflect recent land-use or management changes.
• Specific row and column counts for the final tabular data are not provided, limiting precise assessment of dataset size.

Provenance

Source

U.S. Environmental Protection Agency

Collection Method

Integration of EPA's National Nutrient Inventory with the StreamCat database using a tabular dasymetric apportionment process and an accumulation framework.

Time Range

1987-2017

Freshness

Last updated metadata indicates 2026-04-04, but the underlying data time-range ends in 2017.

Geography

Contiguous United States