3D Hydrography (3DHP) Interest Group

States have a unique opportunity to prepare for the future of hydrography, even as your Statewide Elevation-Derived Hydrography (EDH) data is far from being developed.  As shared in my previous post, USGS's newly published 3DHP datasets and tools like HydroAdd3D, expected to be released later this fiscal year, is laying the groundwork for states to begin taking foundational planning steps to - assess existing hydro workflows, planning and prep to align your existing Hydrolocation data with 3DHP, and building stakeholder awareness so that states will be ready to begin using the HydroAdd3D Tool when it becomes available.

Begin planning today to ensure a smooth transition to 3DHP and the Internet of Water (IoW) and position your state to lead in water resource management and resilience.

Next Steps for States:

State and local governments can begin preparing for their transition to the 3D Hydrography Program (3DHP) by leveraging NSGIC's "3D National Topography Model (3DNTM) Data Acquisition and Management State Planning Guide" [HERE] and the newly available USGS 3DHP 2024 Annual Snapshot [HERE] as a foundation.

Key Planning Steps Include:

1. Initial Transition Planning:
• Analyze the 3DHP snapshot to understand its structure, schema, and integration with the Internet of Water (IoW) [LINK].
• Develop Plan to retire Legacy NHD/WBD Datasets Replace outdated NHD/WBD datasets with the 2024 3DHP snapshot.
• Prepare Hydrolocation datasets for IoW integration by using tools like Geoconnex to ensure discoverability and interoperability [LINK].
2. Assess Current Hydrography Data and Workflows:
• Inventory existing datasets and compare them with the 3DHP snapshot to identify gaps.
• Prioritize critical datasets and applications (e.g., flood management, water quality monitoring) for early migration.
• Review and address inefficiencies in current workflows.
3. Build a 3DHP Data Transition Team:
• Form a team with GIS experts, hydrography stewards, and representatives from key agencies.
• Engage stakeholders at the regional and federal levels (e.g., USGS, NSGIC) for technical guidance and resource-sharing.
4. Develop a Migration Strategy:
• Use the 2024 3DHP snapshot as a baseline to catalog legacy ReachCode data and prepare it for crosswalking to 3DHP mainstem identifiers.
• Reach out to USGS to participate in HydroAdd3D user acceptance testing or pilot programs. Email < hydroadd@usgs.gov >.
5. Incorporate 3DHP Data into Statewide Planning:
• Use the 3DHP snapshot to update hydrologic models, maps, and decision-support systems.
• Identify areas needing new elevation data or EDH integration for future 3DHP development.
6. Build Awareness and Conduct Stakeholder Outreach:
• Host workshops and create communication plans to highlight the long-term benefits of transitioning to 3DHP.
• Emphasize cost savings, improved data accuracy, and compliance advantages.
7. Coordinate with Federal and Regional Partners:
• Work with USGS and neighboring states to align migration efforts, reduce duplication, and prepare for HydroAdd3D.
8. Plan for Data Maintenance:
• Establish workflows and funding streams to ensure annual updates to 3DHP datasets and support ongoing EDH development.
• Synchronize data updates across agencies and ensure compatibility with new features and specifications.

By taking these foundational steps, states will position themselves to successfully adopt 3DHP and modernize their hydrography workflows, ensuring enhanced accuracy, collaboration, and compliance for the future.

Why Use 3DHP and Hydrolocation Data

In preparing these posts I kept asking myself "Why use the 3DHP Snapshot Data", and "Why use HydroAdd3D" to migrate / create new Hydrolocation data on the 3DHP network. Hopefully the information I've provided in these posts will help answer these questions, but if you want more information, I started compiling some additional information in this Google Doc on NSGIC's 3DHPFTN Google Drive [HERE].  Please feel free to add your comments and edits to this working document as we all learn more about "All Things 3DHP".