Description: The National Inventory of Dams (NID) is a congressionally authorized database maintained and published by the U.S. Army Corps of Engineers (USACE), in cooperation with the Association of State Dam Safety Officials, states/territories, and federal agencies.Date Accessed: 02/02/2026Date Downloaded: 02/02/2026Date Uploaded to Portal: ---Fields:Dam Name: Official name of the dam. No abbreviations unless the abbreviation is part of the official name. If no official name exists, use the popular name.Other Names: Names other than the official name (e.g., reservoir name) in common use. Multiple names separated by a semicolon. Blank if not applicable.Former Names: Previous reservoir or dam name(s), if changed. Multiple names separated by a semicolon.NID ID: Official National Inventory of Dams identification number (required). Assigned and maintained by State Dam Safety Offices. Typically begins with a two-letter state abbreviation followed by a unique number/alphanumeric identifier.Other Structure ID: Identification number (e.g., S001, S002) of a separate structure (saddle dam/dike) associated with the dam project. Blank for primary dams.Federal ID: Unique identifier for each dam record. For associated structures: primary dam’s NID ID + Other Structure ID. Otherwise equals the NID ID.Owner Names: Name(s) of the dam owner. Multiple owners separated by a semicolon.Owner Types: Category describing dam owner(s). If more than one owner type, types are separated by a semicolon. Allowed values: Federal; Local Government; Private; Public Utility; State; Tribe; Not Listed.Primary Owner Type: Primary category describing the owner type. If more than one owner type, the main owner type is used.Number of Associated Structures: Number of separate structures (saddle dams/dikes) associated with this project. Does not include appurtenant works (spillways, outlet works, conduits, etc.).Is Associated Structure?: Calculated field. Yes if an Other Structure ID exists (indicating the record is an associated structure to a primary dam).Designer Names: Name of principal firm(s)/agency responsible for design of the dam and major appurtenant operating features and modifications. Original designer listed first, then modification designers (if any). Names separated by a semicolon.Non-Federal Dam on Federal Property: Indicates whether this dam is a non-federal dam located on federal property.Primary Purpose: Main purpose for which the reservoir is used. If more than one purpose, the most important is used.Purposes: Current purpose(s) for which the reservoir is used. Multiple purposes separated by a semicolon in decreasing importance. The first listed purpose is designated as Primary Purpose. Allowed values: Debris Control; Fire Protection, Stock, Or Small Farm Pond; Fish and Wildlife Pond; Flood Risk Reduction (to include Storm Water Management); Grade Stabilization; Hydroelectric; Irrigation; Navigation; Recreation; Tailings; Water Supply; Other.Source Agency: Calculated field. Primary state or federal agency responsible for providing and updating NID data for the dam.State or Federal Agency ID: State or Agency identification number for the dam (if applicable).Latitude: Latitude at dam centerline as a single value in decimal degrees, NAD83.Longitude: Longitude at dam centerline as a single value in decimal degrees, NAD83.State: State where the dam is located.County: County in which the dam is located.Nearest Downstream City/Town: Name of the nearest downstream city/town/village most likely to be affected by floods resulting from dam failure.Distance to Nearest City/Town: Distance from the dam to the nearest affected downstream city/town/village (to the nearest mile, and tenth if appropriate).River or Stream: Official name of the river/stream on which the dam is built. If unnamed, identify as tributary to a named river (e.g., Snake-TR). If offstream, use river/stream name plus “-OS” (e.g., Snake-OS). Alternative formatting may be provided and converted prior to inclusion.Congressional District: Calculated field. Congressional District derived from coordinates. Blank if coordinates are not provided.AIANNH: Calculated field. Name of applicable American Indian/Alaska Native/Native Hawaiian area (reservation/trust land/HHL/etc.).State Regulated Dam: Calculated field. Yes if State Permitting Authority, State Inspection Authority, State Enforcement Authority, and State Jurisdictional Dam are all Yes; otherwise No.State Jurisdictional Dam: Yes if the dam meets the state regulatory organization’s definition of a jurisdictional dam.State Regulatory Agency: Primary state agency with regulatory or approval authority for the dam.State Permitting Authority: Yes if the state has authority to review/approve plans and specifications to construct, enlarge, remove, and abandon dams.State Inspection Authority: Yes if the state has authority to require or perform inspections (at least once every five years) for dams posing a significant threat to human life/property in case of failure.State Enforcement Authority: Yes if the state has authority to require maintenance/remedial work or other actions, including breaching dams when necessary.Federally Regulated Dam: Calculated field. Yes if a Federal Agency is listed as involved in regulatory aspects of the dam; otherwise No.Federal Agency Owner: Federal agency that owns the dam (or a component). Multiple agencies separated by a semicolon.Federal Agency Involvement in Funding: Federal agency/agencies involved in funding. Multiple agencies separated by a semicolon.Federal Agency Involvement in Design: Federal agency/agencies involved in design. Multiple agencies separated by a semicolon.Federal Agency Involvement in Construction: Federal agency/agencies involved in construction. Multiple agencies separated by a semicolon.Federal Agency Involvement in Regulatory: Federal agency/agencies involved in regulation. Multiple agencies separated by a semicolon.Federal Agency Involvement in Inspection: Federal agency/agencies involved in inspection. Multiple agencies separated by a semicolon.Federal Agency Involvement in Operation: Federal agency/agencies involved in operation. Multiple agencies separated by a semicolon.Federal Agency Involvement – Other: Federal agency/agencies involved in other aspects. Multiple agencies separated by a semicolon.Built Under the Authority of the Secretary of Agriculture: Indicates whether the dam was designed and built by NRCS through one of the Watershed Program authorizations.NRCS Watershed Dam Authorization: If applicable, the specific authorization. Allowed values: Flood Control Act of 1944 (Public Law 78-534); 1953 Pilot Watershed Program (Public Law 83-156); Watershed Protection and Flood Prevention Act of 1954 (Public Law 83-566); 1962 Resource Conservation and Development Act (Public Law 87-703).Primary Dam Type: Main type of dam. If more than one type exists, the most dominant is used.Dam Type: Dam type(s). Multiple separated by semicolons. Allowed values: Arch; Buttress; Concrete; Earth; Gravity; Masonry; Multi-Arch; Rockfill; Roller-Compacted Concrete; Stone; Timber Crib; Other.Core: Position, type, and certainty of watertight member. Position: Upstream Facing; Homogeneous dam; Core; Unlisted/Unknown. Type: Bituminous Concrete; Concrete; Earth; Metal; Plastic; Unlisted/Unknown. Certainty: Known; Estimated.Foundation: Foundation material and certainty. Foundation: Rock; Rock and Soil; Soil; Unlisted/Unknown. Certainty: Known; Estimated.Dam Height: Height (ft) to nearest foot. Vertical distance between the lowest point on the crest and the lowest point in the original streambed.Hydraulic Height: Hydraulic height (ft) to nearest foot. Vertical difference between maximum design water level and lowest point in original streambed.Structural Height: Structural height (ft) to nearest foot. Vertical distance from lowest excavated foundation to the top of the dam (top refers to parapet wall, not crest).NID Height: Calculated field. Maximum of Dam Height, Structural Height, and Hydraulic Height.NID Height Category: Calculated field. Based on NID Height: less than 25 ft; 25-49 ft; 50-100 ft; greater than 100 ft.Dam Length: Length (ft) along the top of the dam including attached spillway/powerplant/navigation lock/fish pass when these form part of the dam length.Volume (of Dam): Total cubic yards of materials in the dam structure. Includes integral powerhouse/locks/spillways only if integral and required for structural stability.Year Completed: Four-digit year the original main dam structure was completed. Blank if unknown and no reasonable estimate exists.Year Completed Category: Calculated field. Category based on Year Completed (e.g., before 1900, 1900-1909, … Since 2000, Undetermined).Year Modified: Four-digit year major modifications/rehabilitation were completed.Modification Type: Type of modification. Allowed values: Foundation; Hydraulic; Mechanical; Seismic; Structural; Other.NID Storage: Calculated field. Maximum of Normal Storage and Maximum Storage.Maximum Storage: Maximum storage (acre-feet). Total storage below maximum attainable water surface elevation (includes surcharge storage).Normal Storage: Normal storage (acre-feet). Total storage below normal retention level (includes dead/inactive; excludes flood control/surcharge). Normally dry dams = 0. Blank if unknown (not zero).Surface Area: Surface area (acres) of the impoundment at normal retention level.Drainage Area: Drainage area (square miles) that drains to the dam location.Maximum Discharge: Spillway discharge capacity (cfs) when reservoir is at maximum designed water surface elevation.Spillway Type: Type of spillway. Allowed values: Controlled; Uncontrolled; None.Spillway Width: Width (ft) of spillway available for discharge at maximum designed water surface elevation (open channel: bottom width; pipe/drop inlet: diameter).Number of Locks: Number of existing navigation locks for the project.Length of Locks: Length (ft) of the primary navigation lock to the nearest foot.Lock Width: Width (ft) of the primary navigation lock to the nearest foot.Length of Secondary Lock: Length (ft) of the secondary navigation lock to the nearest foot.Secondary Lock Width: Width (ft) of the secondary navigation lock to the nearest foot.Outlet Gate Type: Type(s) of spillway and controlled outlet gates (up to five types in decreasing size order, separated by semicolons, followed by number of gates). Allowed values: None; Uncontrolled; Tainter (radial); Vertical Lift; Roller; Bascule; Drum; Needle; Flap; Slide (sluice gate); Valve; Other controlled.Data Last Updated: Calculated field. Date data was submitted to USACE for inclusion in the NID, or date the regulatory agency updated the NID database directly.Last Inspection Date: Date of the most recent periodic or comprehensive inspection of the dam prior to NID data transmittal.Inspection Frequency: Scheduled frequency interval for periodic/comprehensive inspections (years).Hazard Potential Classification: Potential downstream hazard from failure or mis-operation (not a condition/risk rating). Allowed values: Low; Significant; High; Undetermined.Condition Assessment: Condition based on available information. Allowed values: Satisfactory; Fair; Poor; Unsatisfactory; Not Rated; Not Available.Condition Assessment Date: Date of the most recent condition assessment prior to NID data transmittal.Operational Status: Operational/remediation status based on available information. Allowed values: Normal Operations; Under Investigation, Planning, Permitting, or Design for Remediation; Under Remediation; Enforcement Pending/Ongoing; Not Applicable; Not Available.Operational Status Date: Date of the most recent operational status assessment prior to NID data transmittal.Emergency Action Plan (EAP Prepared): Indicates whether an Emergency Action Plan is developed by the owner. Allowed values: Yes; No; Not Required (by regulatory agency).EAP Last Revision Date: Date of the most recent revision of the EAP prior to NID data transmittal.Last EAP Exercise Date: Date of the most recent EAP exercise (U.S. Army Corps of Engineers dams only).Emergency Contacts Updated: Date the EAP emergency contact lists were last updated (U.S. Army Corps of Engineers dams only).EAP Meets FEMA Guidelines: Indicates whether the EAP meets FEMA 64 guidelines (U.S. Army Corps of Engineers dams only).Inundation Maps Added to NID: Indicates whether inundation maps/scenarios are accessible through the NID.Website URL: Website for more information on the specific dam or regulatory agency.