The full Mississippi Sound Watershed, split into basins according to MDEQ's heuristics

The Mississippi Sound Watershed is made up of HUC4s 0317 (Pascagoula River basin) and 0318 (Pearl River basin). The Mississippi Department of Environmental Quality recognizes a portion of HUC 0317, specifically the HUC8 03170009, as a separate basin, the Coastal Streams Basin. Because waterways in that HUC8 do not in fact flow into the Pascagoula River, it makes sense for the MSEP to recognize this delineation as well.

Usage

basins_mdeqExt

Format

A Simple feature collection with 3 features and 1 field.

basin

Basin, according to MDEQ designation.

geometry

POLYGON of the basin.

Source

National Hydrography Dataset, as downloaded from USGS on 6/4/2025 from https://prd-tnm.s3.amazonaws.com/StagedProducts/Hydrography/NHD/State/GPKG/NHD_H_Mississippi_State_GPKG.zip.

Details

MDEQ only delineates these watersheds within the state of MS, however, so MSEP has made the current delineation by subsetting HUCs from the National Hydrography Dataset, and extending the Coastal Streams Basin into Louisiana and Alabama based on the HUC8 of 03170009.

The raw data were subsetted to the geopackage file msep_hucs.gpkg using the script subset_NHD.R. The subset was further processed into this final form in make_mdeqish_boundaries.R. Both scripts and the subsetted geopackage file are available in the data-raw directory of the package repository at: https://github.com/CMEP-MS/msepBoundaries.