The USGS National Hydrography Dataset (NHD) downloadable data collection from The National Map (TNM) is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions. In addition to this geographic information, the dataset contains metadata that supports the exchange of future updates and improvements to the data. The NHD supports many applications, such as making maps, geocoding observations, flow modeling, data maintenance, and stewardship. For additional information on NHD, go to https://www.usgs.gov/core-science-systems/ngp/national-hydrography.

DWR was the steward for NHD and Watershed Boundary Dataset (WBD) in California. We worked with other organizations to edit and improve NHD and WBD, using the business rules for California. California's NHD improvements were sent to USGS for incorporation into the national database. The most up-to-date products are accessible from the USGS website. Please note that the California portion of the National Hydrography Dataset is appropriate for use at the 1:24,000 scale.

For additional derivative products and resources, including the major features in geopackage format, please go to this page: https://data.cnra.ca.gov/dataset/nhd-major-features Archives of previous statewide extracts of the NHD going back to 2018 may be found at https://data.cnra.ca.gov/dataset/nhd-archive.

In September 2022, USGS officially notified DWR that the NHD would become static as USGS resources will be devoted to the transition to the new 3D Hydrography Program (3DHP). 3DHP will consist of LiDAR-derived hydrography at a higher resolution than NHD. Upon completion, 3DHP data will be easier to maintain, based on a modern data model and architecture, and better meet the requirements of users that were documented in the Hydrography Requirements and Benefits Study (2016). The initial releases of 3DHP include NHD data cross-walked into the 3DHP data model. It will take several years for the 3DHP to be built out for California. Please refer to the resources on this page for more information.

The FINAL,STATIC version of the National Hydrography Dataset for California was published for download by USGS on December 27, 2023. This dataset can no longer be edited by the state stewards. The next generation of national hydrography data is the USGS 3D Hydrography Program (3DHP).

Questions about the California stewardship of these datasets may be directed to nhd_stewardship@water.ca.gov.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

The 3D Hydrography Program (3DHP) data is an integrated, National, 3D-enabled hydrologic dataset derived from the USGS 3D Elevation Program (3DEP) data. For areas where Elevation-derived Hydrography (EDH) has not yet been collected, 3DHP data is supplemented by hydrologic vector data from the National Hydrography Dataset (NHD). As further EDH data is collected, it will replace the NHD data in those areas. 3DHP data ingested from EDH sources includes ‘value added’ catchments and flowline network derivative attributes. All the data is open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. 3DHP datasets include a three-dimensional (3D) hydrography network generated from, and integrated with, elevation data from the 3DEP to better represent stream gradients and channel conditions, along with waterbodies, hydrologic units, hydrologically enhanced elevation and other surfaces, and more consistent and accurate attributes. This product is new in federal fiscal year 2025 (FY25), and consists only of vector data in a series of feature classes. The product represents the 3DHP dataset and the schema in which it is contained as of September 30, 2024 Future Annual Staged Product releases will reflect the schema at the time the product is generated and include more EDH-sourced data holdings.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

These data depicts 3D Hydrography Program (3DHP) Data Collaboration Announcement (DCA) hydrography data acquisition projects from federal fiscal year (FY) 2024 to present. The DCA provides a mechanism for partnering with the USGS and other Federal agencies to acquire high-quality hydrography data to provide the Nation with high-resolution hydrographic products to support a broad array of applications.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

This dataset contains the initial 3D Hydrography Program (3DHP) flow network topology, which is based on the final High Resolution National Hydrography Dataset (NHD), and a set of mainstem river identifiers based on the Medium resolution NHDPlus Version 2 (NHDPlusV2). The 3DHP flow network topology and mainstem identifiers contained in this data release add two key pieces of information to the flow table of the National Hydrography Dataset: 1) at every junction, one and only one main upstream and downstream connection has been identified 2) every "in network" flowline has been assigned a mainstem identifier that places it into a hierarchy of rivers and drainage basins. For description of 1 and 2 and additional background, see supplemental information. Files included: - HU6_mainstem_outlets.geojson Outlet locations of six-digit hydrologic units along mainstem network. - nhd_3dhp_conus_mainstems.zip Zipped table in Comma Separated Values (csv) format containing NHD permanent identifiers and mainstem Uniform Resource Identifiers (URIs) for the Contiguous United States (CONUS). - nhd_3dhp_conus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for CONUS. - nhd_3dhp_conus_vpu_membership.zip Zipped csv table containing NHD permanent identifiers and which Vector Processing Unit (VPU) they belong in. - nhd_3dhp_oconus_mainstems.zip Zipped csv table containing NHD permanent identifiers and mainstem URIs for areas Outside of the Contiguous United States (OCONUS). - nhd_3dhp_oconus_flownetwork.zip Zipped csv table containing from / to NHD permanent identifiers (from flowline to flowline) and upmain / downmain attributes for OCONUS. -3dhp_flownetwork.zip Zipped csv table containing from / to 3DHP identifiers (from flowline to flowline) and upmain / downmain attributes. - nhd_3dhp_nonnetwork_mainstems.zip Zipped csv table containing mainstem identifiers for features not included in the NHD flow table. - nhd_final_registry.zip Zipped csv table containing all expected flowlines from the final NHD -- excludes geometry. - nhd_reachcode_mainstem.zip Zipped csv table containing a mapping between mainstem identifiers and NHD reachcodes. - nhd_3dhp_region_connections.zip Zipped csv table containing connections between vector processing unit regions defined by four-digit hydrologic unit. - nhd_3dhp_mainstem_summary.zip Zipped csv table containing summary information about mainstems contained in nhd_3dhp_conus_mainstems.zip and nhd_3dhp_oconus_mainstems.zip.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives.Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp.See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

The better results are written in bold, they include multi-view models.

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. The 3DHP_all comprises a national network of flowlines, hydrolocations, and water bodies, and will include catchments, drainage areas, and flow network derivatives as they are populated in the future. The 3DHP_all service will provide access to a 3D-enabled geospatial hydrography vector dataset built from 3DHP data and intended to provide the most comprehensive but general rendering of 3DHP data. 3DHP data is derived from elevation-derived hydrography (EDH) Elevation-Derived Hydrography Specifications | U.S. Geological Survey (usgs.gov) where available. Where EDH has not been collected, 3DHP data will be supplemented by data from the National Hydrography Dataset (NHD) National Hydrography Dataset | U.S. Geological Survey (usgs.gov). As further EDH data is collected, the EDH data will replace the NHD data in that data collection area. 3DHP data ingested from EDH sources will include catchments, drainage areas derived from catchments, and flowline network attribute derivatives. Use Constraints: _ None. All data are open and non-proprietary. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of this data may no longer represent actual conditions. Users should not use this data for critical applications without a full awareness of its limitations. This dataset is not intended to be used for site-specific regulatory determinations. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data.For additional information on the 3DHP, go to https://www.usgs.gov/3dhp. See https://apps.nationalmap.gov/help/ for assistance with The National Map viewer, download client, services, or metadata.

The USGS Network Attributes for the High-Resolution National Hydrography Dataset (NHD) introduces foundational features for the 3D Hydrography Program (3DHP). These attributes provide critical details about flow paths, network connectivity, and hydrological relationships within surface water systems. By building on the NHD's high-resolution data, the attributes enable comprehensive hydrological analyses, such as tracing water flow, calculating upstream and downstream impacts, and modeling watershed dynamics. This functionality is essential for advancing the transition from legacy hydrography datasets to the modern 3DHP framework.The network attributes allow researchers and practitioners to simulate water movement across complex networks, making the data highly applicable for decision-making in water resource management, flood mitigation, and ecosystem conservation. With enhancements like flow direction indicators, network tracing capabilities, and hydrological connectivity metrics, users can better understand water system dynamics and dependencies. These features also support hydrological and geospatial modeling at multiple scales, making them valuable for federal, state, and local applications.This resource aligns closely with the goals of the 3D Hydrography Program to integrate elevation-derived hydrography with national datasets. By providing advanced network attributes, the dataset facilitates seamless integration with tools for elevation data, enabling users to create more accurate and detailed 3D hydrography networks. This advancement is crucial for environmental planning, disaster preparedness, and water policy development, ensuring that the network attributes serve both immediate and long-term needs in geospatial science.

The Watershed Boundary Dataset (WBD) from USGS' The National Map (TNM) defines the perimeter of drainage areas formed by the terrain and other landscape characteristics. The drainage areas are nested within each other so that a large drainage area, such as the Sacramento River, will be composed of multiple smaller drainage areas, such as the Feather River. Each of these smaller areas can further be subdivided into smaller and smaller drainage areas. The WBD uses six different levels in this hierarchy, with the smallest averaging about 30,000 acres. The WBD is made up of polygons nested into six levels of data respectively defined by Regions, Subregions, Basins, Subbasins, Watersheds, and Subwatersheds. For additional information on the WBD, go to https://www.usgs.gov/core-science-systems/ngp/national-hydrography/watershed-boundary-dataset. DWR was the steward for NHD and WBD in California. We worked with other organizations to edit and improve NHD and WBD, using the business rules for California. California's WBD improvements are sent to USGS for certification and incorporation to the national geodatabase. The certified WBD is included within the National Hydrography Dataset downloadable file geodatabase, and is also available in shapefile format and as web map services accessible from the USGS website. (https://www.usgs.gov/core-science-systems/ngp/national-hydrography/access-national-hydrography-products).

The final static version of the WBD was published in January 2025. No edits to this dataset are being accepted by USGS. Future mapping of drainage areas will be done by USGS as the 3D Hydrography Program (3DHP) is built out. DWR and its stewardship partners are actively producing LiDAR-derived hydrography data for inclusion in the California portion of 3DHP data and eventually its companion set of drainage areas. For now, the WBD is considered the authoritative source for watershed delineations in California.

The U.S. Geological Survey (USGS) recently launched the 3D Hydrography Program (3DHP) with the goal to build a national hydrographic framework that is integrated with 3D Elevation Program (3DEP) elevation data. The 3DHP framework begins with the legacy National Hydrography Dataset (NHD) that is replaced as newly acquired elevation-derived hydrography data becomes available. The data model for the framework is designed to leverage terrain and flow characteristics inherent in the derived hydrography and improve hydrologic modeling and data sharing capabilities. The initial version of the framework is now available as a web service. This poster will highlight important aspects of accessing the web service and using the 3DHP network.

The USGS 3D Hydrography Program (3DHP) is a cutting-edge initiative designed to modernize the nation’s hydrography data by integrating it with high-resolution 3D elevation data from the USGS 3D Elevation Program (3DEP). This program seeks to establish a seamless, three-dimensional mapping framework of surface water systems, supporting critical activities such as water resource management, environmental conservation, disaster preparedness, and infrastructure planning. Through advanced geospatial tools and data integration, the 3DHP aims to improve data accuracy and usability, enabling a wide range of applications, from hydrologic modeling to ecosystem monitoring. The program provides open-access datasets and services, fostering collaboration among federal, state, and local agencies, and addressing the growing need for precise, reliable water resource data in a changing climate. It aligns with the broader USGS vision of creating a unified 3D National Topography Model (3DNTM) to support robust geospatial analysis and decision-making nationwide.

The Canadian Hydrospatial Network (CHN) is an analysis-ready geospatial network of features that help enable the modelling of surface water flow in Canada. The six main layers and feature types are: flowlines, waterbodies, catchments, catchment aggregates, work units, and hydro nodes. Where possible the CHN is derived from high resolution source data such as Light Detection and Ranging (LiDAR) derived Digital Elevation Models (DEMs) and aerial imagery, to name a few. If existing provincial or territorial hydrographic networks meet the standards, they are incorporated into the CHN, otherwise automatic extraction methods are used on the high-resolution source data. To provide full network connectivity, if neither of these methods is possible in a region, the NHN is converted into the CHN until higher-resolution source data is available. Additional value-added attributes are included in the CHN to aid modelling, such as stream order and reach slope. The CHN physical model and features are also closely aligned and harmonized with the USGS 3DHP hydrographic network, which aids trans-border modelling. Where possible geonames (i.e. toponyms) are also added. The CHN is produced and disseminated by hydrologically connected geographic areas called work units. Work units can contain just one watershed, several small adjacent watersheds outletting into a large body of water, or be one of many parts of a larger watershed. In all cases, the features of a work unit are hydrologically connected. This is a more natural approach to data delivery, in comparison to data that is split into tiles. A generalized work unit index file is provided in the downloads to help users decide which files to download. For more information on the CHN please visit the project webpage: https://natural-resources.canada.ca/canadian-hydrospatial-network

The USGS 3D Hydrography Program (3DHP) ArcGIS REST service (3DHP_all) from The National Map is the first of several data services that will be delivered by the 3D Hydrography Program. NHDPlus_HR (MapServer) The USGS NHDPlus High Resolution service, NHDPlus_HR, a part of The National Map, is a comprehensive set of digital spatial data comprising a nationally seamless network of stream reaches, elevation-based catchment areas, flow surfaces, and value-added attributes that enhance stream network navigation, analysis, and data display. wbd (MapServer) This file contains Hydrologic Unit (HU) polygon boundaries for the United States, Puerto Rico, and the U.S. Virgin Islands. The data is a seamless National representation of HU boundaries from 2 to 14 digits compiled from U.S. Geological Survey (USGS) National Hydrography Dataset (NHD) and U.S. Department of Agriculture (USDA) National Resources Conservation Service (NRCS) Watershed Boundary Dataset (WBD) sources. nhd (MapServer) The USGS National Hydrography Dataset (NHD) service from The National Map is a comprehensive set of digital spatial data that encodes information about naturally occurring and constructed bodies of surface water (lakes, ponds, and reservoirs), paths through which water flows (canals, ditches, streams, and rivers), and related entities such as point features (springs, wells, stream gages, and dams). The information encoded about these features includes classification and other characteristics, delineation, geographic name, position and related measures, a "reach code" through which other information can be related to the NHD, and the direction of water flow. The network of reach codes delineating water and transported material flow allows users to trace movement in upstream and downstream directions.

The USGS Data Collaboration Announcement (DCA) Portal serves as a central platform for facilitating partnerships that enhance geospatial data acquisition as part of the 3D National Topography Model (3DNTM). Through the FY25 3DHP DCA, the portal focuses on integrating 3D Elevation Program (3DEP) and 3D Hydrography Program (3DHP) data acquisition, providing tools, workflows, and funding guidance for collaborative projects among federal, state, and local agencies. This coordinated approach allows for the development of seamless, high-resolution datasets that improve resource management and decision-making.The portal enables agencies to pool funding and align priorities to achieve shared goals in mapping projects. It supports initiatives such as elevation-derived hydrography (EDH), seamless integration of elevation and hydrography datasets, and improvements in 3D data quality. This helps address challenges in areas like flood risk management, water resource planning, and disaster preparedness. Participants benefit from transparent processes, joint funding agreements, and technical resources designed to streamline project implementation.In addition to collaboration tools, the portal provides access to detailed information about priority data requirements, application timelines, and partnership opportunities. It fosters innovation by supporting projects that advance the USGS mission of producing accurate, reliable geospatial data critical for federal and state mapping needs. The DCA Portal exemplifies a model for efficient, collaborative data development that enhances national geospatial infrastructure.

The National States Geographic Information Council (NSGIC) and U.S. Geological Survey (USGS) have established a 3D Hydrography Program for the Nation (3DHP FTN) cooperative project to engage states and other partners in modernizing national hydrography by deriving new data from 3D Elevation Program (3DEP) data. The NSGIC 3DHP FTN hub is intended to serve as a workspace for the collection and dissemination of project information and products. Those interested in participating in the project are invited to join the 3DHP FTN Interest Group and/or the 3DHP FTN State Teams communities at My.NSGIC.Contact Information:Lynda Wayne, Project Manager

Phil Worrall, Project Engineer and Hub Manager

The NSGIC 3D Hydrography Program (3DHP) Activities Dashboard is an interactive tool that visualizes state and regional hydrography initiatives across the United States. Users can explore various projects, access case studies, review state plans, and examine examples of hydrography-related documents such as Statements of Work (SOW), Requests for Proposals (RFP), and Requests for Information (RFI). The dashboard also provides links to state-specific hydrography data, facilitating information sharing and collaboration among stakeholders involved in hydrography data development and management.