Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Skip to content

Indicators of Hydrologic Alteration in North Carolina Catchments: Small Ponds and Artificial Drainage

Metadata Updated: October 30, 2025

Alterations to stream hydrology, which include changes in stream geomorphology, are primary impacts of anthropogenic disruption. In North Carolina, hydrological alterations lead to environmental impacts through degraded ecosystems and water quality. In collaboration with the North Carolina Department of Environmental Quality, Division of Mitigation Services (DMS), the USGS South Atlantic Water Science Center datasets are proxy measurements of the extent of altered hydrology in riverine systems across the State of North Carolina. The datasets consist of an inventory and characterization of small scale (mostly agricultural) ponds and artificial drainages, which are both significant hydrologic modifications in the region. Ponds are impoundments that are often used for flood control, water supply, irrigation, and recreation. The impoundments constitute modifications to the stream network that fragment the aquatic habitat by limiting river network connectivity necessary for fish passage. A dataset was developed to quantify small ponds as proxy measures of barriers to flow in stream networks across the State. The USGS used a combination of the 2016 National Land Cover Dataset (NLCD) and the National Hydrography Dataset (NHD) to identify 105,560 small ponds that are less than 10 acres is surface area. The features are more refined than larger scale assessments such as those in the NHDPlus High Resolution and provide a starting point for determining mitigation strategies. Artificial drainage has major ecosystem impacts through the development of extensive ditch networks that reduce storage and induce large-scale vegetation changes. This has been a widespread practice of water table management for agriculture in Eastern North Carolina. However, these features are challenging to identify because the structure has been determined by non-natural factors. A dataset of open ditches was processed by calculating terrain openness (also called positive openness): a value based on a line-of-sight approach to measure the surrounding eight zenith angles as viewed above the landscape surface. The result from calculating openness with high resolution lidar-derived digital elevation models (DEMs) was then refined by masking natural water ways (stream valleys) and channels that are associated with transportation and urban areas.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

Downloads & Resources

Dates

Metadata Created Date September 14, 2025
Metadata Updated Date October 30, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 14, 2025
Metadata Updated Date October 30, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-6172b4ccd34ea36449a88174
Data Last Modified 2022-07-12T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id 8fcc08f3-59ca-465c-8cbf-323c103aaefb
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -84.4116, 33.7618, -75.8128, 36.5999
Source Datajson Identifier True
Source Hash 2986513d790dfbd4060a700e50b9deab530dc84b1715afc6186b81d250e3485a
Source Schema Version 1.1
Spatial {"type": "Polygon", "coordinates": -84.4116, 33.7618, -84.4116, 36.5999, -75.8128, 36.5999, -75.8128, 33.7618, -84.4116, 33.7618}

Didn't find what you're looking for? Suggest a dataset here.