DATABASE
How to Submit and Update Data
How to Submit and Update Data
Currently, the National Levee Database includes information for more than 7,000 levee systems. A data change request can be submitted at any time by anyone. Change requests are coordinated with the entity responsible for the specific levee(s).
Data changes can include updates to an existing levee system or the addition of data for a new levee system not currently in the database. Examples of updated or new data might include geospatial information (e.g., levee alignment centerline, crest profile, levee area) or levee attributes (e.g., design and construction information).
What is a levee?
A levee is a humanmade barrier with the primary purpose of reducing the frequency of flooding to a portion of the floodplain, sometimes referred to as a levee system. Most levees are built along waterways and typically do not have water against or on them all the time. Many levees connect to or rely upon high ground, such as a railroad embankment to create an unbroken line of defense against flood waters. The National Levee Database includes all known levees in the U.S. See the anatomy of a levee under Levee Basics for more information.
Updating Data for Levees in the National Levee Database
Most levees in the National Levee Database have a known entity responsible for operation and maintenance. These entities are typically assigned as data managers for specific levees. Typically, only one organization can edit information for a given levee system.
If submitting a change to an existing levee where a data manager is assigned, the NLD Helpdesk will coordinate with the entity responsible for the levee and related data to facilitate review and approval of the data change request.
In some cases, levees in the National Levee Database do not have a known entity responsible for operation and maintenance. In these cases, no data manager is assigned. Updated or new data submitted for levees without an assigned data manager are reviewed and updated by the National Levee Database Helpdesk.
Submitting Data for New Levees
The following requirements apply when submitting data for a newly constructed levee, or a levee that is not yet in the National Levee Database.
- The proposed system must meet the definition of a levee. Standalone channel and canal projects typically do not meet the levee definition. If you are unsure, you can contact the National Levee Database Helpdesk who can help you determine if your project meets the definition of a levee.
- The data package needs to include an alignment (levee embankments, floodwalls and/or closure structures).
- Top of feature elevations are highly recommended but if immediately unavailable, the National Levee Database Helpdesk can assist with high resolution elevation extractions.
- The data package should also include an inundation area derived using hydrologic and hydraulic processes. This information is used to generate a shaded area in the National Levee Database representing a conservative estimate of the lands from which flood water would be excluded by the levee system. If unavailable, the National Levee Database Helpdesk can assist in generating a leveed area after a top of levee elevation determination has been made.
How to Submit a Request
To submit a request to update data for an existing levee system or add data for a new levee system, follow either of the two processes outlined below. Both processes will allow a user to submit or request changes.
- Email the Helpdesk at NLD@usace.army.mil. Indicate the levee system by ID and name along with the proposed data change if it is an existing levee. If the data is for a new levee and it does not overlap with an existing levee in the National Levee Database, please indicate that in the email. For spatial information updates or new levee submittals, the preferred formats are geopackage, geojson, or file geodatabase as primary formats. Shapefile and CAD files are acceptable but only if primary formats are not available. For non-geospatial updates, simply indicate the proposed field entry change or document upload.
- Complete a web form for a data change request. Fill out the form, attach any files, and submit. If files are in excess of 100 megabytes, then fill out the form and indicate that you have large files in the request block and the Helpdesk will coordinate a separate file transfer.
Update Steps and Typical Timelines
| Update Step | Typical Response | Activity | Next Step | Timeframe from Submittal |
|---|---|---|---|---|
| Data change request is submitted | Helpdesk confirms receipt of request by email | Helpdesk logs the request | Helpdesk reviews data submittal to verify completeness | Within 48 hours |
| Helpdesk reviews data submittal | Determines coordination needed with relevant data managers | Notify assigned data managers about the request and impact it may have on existing data | Receive response from data manager(s). Notify data submitter of response and if any clarification is needed. | Within 96 hours |
| Data manager review | Data manager concurs or non-concurs with requested change | Data manager notifies Helpdesk of response | Data change proceeds if no additional coordination required | Within 7 days |
| Additional reviews (when applicable) | Reviewer concurs or non-concurs with requested data change | Reviewer notifies Helpdesk of response | Await other reviewer responses when applicable | Within 7 days |
| Data change made if concurrence from all reviewers is received | Notify data submitter of concurrence or non-concurrence on coordination steps | If concurrence with change, then data change is made | If concurrence, then data change proceeds and made. If non-concurrence, await response from submitter after reason explained. | Within 10 days |
The above table summarizes the general steps and timeframe for receiving, reviewing, and coordinating data change requests. While most reviews of data change requests are completed within this timeframe, review times can vary depending on the complexity and volume of data changes requested.
On average, requests to input a new levee in the National Levee Database are complete within 7 to 10 days. However, this timeline can vary based on data quality. For example, if a new levee has good top of levee elevation data and a leveed area/inundation area provided, then the data entry can be just a few days. If the data does not include those key baseline data elements, then the process can be several weeks as that data is created using available open-source data. See "Submitting Data for New Levees" for more information.
Updates to data for a levee already in the National Levee Database can take longer depending on the number of entities who the request must be coordinated with. For example, levees that are operated and maintained by a local entity, but for which the U.S. Army Corps of Engineers has oversight can take 14 to 21 days to complete.
