Source directory

Every useful public source, with its limits visible.

Start with official records, add hydrology or regulatory context, then use research and community sources to fill gaps. This catalog was reviewed 2026-07-19; links and upstream schemas can still change.

total source systems

official sources

research datasets

community sources

Feeds, APIs, and data tools

One live upstream is integrated directly; the remaining interfaces are linked to their authoritative provider so their terms and context stay intact.

USACE NID FeatureServer

ArcGIS REST API

Powers the bounded live search and national-count endpoints on DamWatch USA.

integrated

USACE CWMS Data API

REST API

Reservoir, river, location, level, and time-series data from Corps water-management offices.

linked

Reclamation Information Sharing Environment

REST API and downloads

Reclamation water and power observations, locations, and time series.

linked

USGS Water Services

REST API

Machine-readable current conditions, daily values, statistics, and site information.

linked

USACE Dams RSS directory

RSS directory

Official USACE news and news-release feeds filtered by the Dams category.

linked

Bureau of Reclamation RSS newsroom

RSS directory

Official Reclamation newsroom feed discovery for water, power, and dam updates.

linked

FERC accepted filings feed

RSS feed

Current accepted FERC filings; hydropower users should filter by project docket and verify in eLibrary.

linked

Official federal sources

National inventories, federal portfolios, regulation, monitoring, safety guidance, and geospatial context.

National Inventory of Dams

U.S. Army Corps of Engineers

Interactive mapDownload

The national inventory assembled from state and federal regulator submissions, covering more than 90,000 U.S. dams.

Best for

Dam identity, location, ownership, purpose, dimensions, hazard potential, condition fields, and regulator-reported attributes.

Caution: Hazard potential describes consequences of failure, not the probability that a dam will fail. Verify safety decisions with the responsible regulator.

Open source

NID Public Feature Service

U.S. Army Corps of Engineers

API / GIS service

The public ArcGIS FeatureServer used by this site for bounded, paged live inventory queries.

Best for

GIS clients, reproducible API queries, state filtering, and selected feature exports.

Caution: The service caps result pages. Applications must paginate and should retain the upstream DATA_UPDATED field.

Open source

National Dam Safety Program

Federal Emergency Management Agency

Guidance

Federal dam-risk guidance, state assistance, rehabilitation grants, training, and emergency-planning resources.

Best for

Preparedness, emergency action planning, risk communication, grant programs, and federal guidance documents.

Open source

Projects & Facilities Database

U.S. Bureau of Reclamation

Interactive mapDirectory

Profiles Reclamation dams, powerplants, and water projects across the western United States.

Best for

Federal project histories, facility facts, operating regions, and Reclamation contacts.

Open source

USACE Dam Safety Program

U.S. Army Corps of Engineers

GuidanceDirectory

Safety program information for the Corps-managed dam portfolio and national dam-safety activities.

Best for

USACE ownership, risk-management policy, and district-level follow-up.

Open source

Hydropower Licensing and Dam Safety

Federal Energy Regulatory Commission

DirectoryGuidance

Licensing, dockets, inspection guidance, environmental review, and public participation for non-federal hydropower projects.

Best for

License status, filings, relicensing, public comments, dam-safety oversight, and environmental records.

Open source

Water Data for the Nation

U.S. Geological Survey

Interactive mapAPI / GIS serviceDownload

Current and historical observations from stream, lake, reservoir, precipitation, water-quality, and groundwater monitoring locations.

Best for

Water levels, streamflow, reservoir observations, time series, and nearby monitoring stations.

Caution: A monitoring site is not a dam record; join by geography and verify station context.

Open source

The National Map — Hydrography

U.S. Geological Survey

Interactive mapAPI / GIS serviceDownload

National hydrography, elevation, boundaries, and topographic layers useful for watershed and dam context.

Best for

Streams, waterbodies, watersheds, terrain, and reproducible geospatial basemaps.

Open source

State regulator gateways

The best route to state-specific rules, inspections, permits, contacts, and emergency-planning responsibility.

State Dam Safety Program Directory

Association of State Dam Safety Officials

DirectoryGuidance

A gateway to the state and territorial agencies that regulate most non-federal dams.

Best for

Inspection questions, state rules, emergency contacts, permits, and the regulator responsible for a specific dam.

Caution: ASDSO is a nonprofit association; linked state agencies are the authoritative regulators.

Open source

Research datasets

Incident, performance, and globally harmonized datasets built for analysis rather than regulation.

National Performance of Dams Program

Stanford University

DirectoryGuidance

Research and records focused on dam incidents, failures, and operational performance in the United States.

Best for

Incident and performance research, terminology, and historical failure study.

Open source

Global Reservoir and Dam Database (GRanD)

Global Water System Project / NASA SEDAC

Download

A globally harmonized research dataset of large dams and reservoirs.

Best for

Cross-country research, large-reservoir comparison, and global hydrologic modeling.

Caution: Coverage criteria and update cadence differ from the NID; review licensing and metadata before reuse.

Open source

Community and unofficial sources

Valuable open mapping and restoration records that require attribution and source-by-source verification.

National Dam Removal Database

American Rivers

Interactive mapDownload

A national compilation of documented dam removals and river-restoration outcomes.

Best for

Removal history, restoration case studies, and identifying removal projects not represented as active inventory dams.

Caution: Advocacy-maintained data should be cross-checked with owners, regulators, and project documents.

Open source

OpenStreetMap

OpenStreetMap contributors

Interactive mapAPI / GIS serviceDownload

Community-maintained geographic features, including waterway=dam, reservoirs, access points, and nearby infrastructure.

Best for

Open geospatial context, local mapping, names, access geometry, and features absent from national datasets.

Caution: Completeness and accuracy vary. Preserve Open Database License attribution and verify critical facts.

Open source

Wikidata

Wikimedia Foundation and contributors

API / GIS serviceDownload

Structured, collaboratively maintained entities for many notable dams, reservoirs, rivers, operators, and historic events.

Best for

Entity identifiers, multilingual names, linked references, and knowledge-graph research.

Caution: Community assertions vary in sourcing; follow each statement to its cited reference.

Open source