The Choptank River Watershed is located on the western edge of Delaware and resides in Kent County. The headwaters of the Chester River lie to the north and Marshyhope Creek is to the south. The Choptank River Watershed consists of Tappahanna Ditch in the northern portion of the watershed, Culbreth Marsh Ditch in the center, and Cow Marsh Creek in the lower portion. Both Tappahanna Ditch and Culbreth Marsh Ditch drain to Mud Millpond, which is situated at the Maryland-Delaware state line. The pond discharges to the Choptank River in Delaware, which meanders southward, where Cow Marsh Creek connects in before continuing into Maryland.
The drainage area of the Choptank River Watershed within Delaware is approximately 97 mi2.
The land use in the watershed is dominated by agriculture, wetlands and forest.
The riparian habitats associated with the Choptank include some of the finest and most diverse habitats in Kent County and are home to many species or rare plants and rare animals.
The Chester/ Choptank River Watershed received an overall wetland grade of B. Depression
(B), and riverine
(B) wetland types were assessed and graded (grade in parenthesis) in this watershed. The most common stressors to these wetlands were invasive plant species, selective forestry, microtopography alterations, ditching, mowing, and roads in the wetland, and development, channelized streams, agriculture, and roads in the lands surrounding the wetland (buffer). The complete reports for this assessment will become available in 2021 online
, data is currently available.
Concerns in the watershed include low dissolved oxygen, nutrient over-enrichment, and high levels of bacteria. There are no active point sources discharging nutrients or bacteria into Choptank River, therefore, all pollutants are coming from nonpoint sources.
The designated uses for the Choptank River Watershed include primary contact recreation, secondary contact recreation, fish, aquatic life and wildlife, agricultural water supply, and industrial water supply.
Nutrient TMDLs for the Choptank River Watershed include a yearly-average cap on total nitrogen at 1,359 pounds per day and a 40% reduction in phosphorus levels. Also, the nonpoint source bacteria load in the Choptank requires a 29% reduction.
EPA established a Total Maximum Daily Load for nitrogen, phosphorus, and sediment for the entire Chesapeake Bay Watershed. This TMDL requires reductions of approximately 24% for nitrogen and 20% for phosphorus between 2009 and 2025 from all of the Chesapeake watersheds within Delaware. Sediment loads from Delaware's portion of the Chesapeake must remain at 2009 levels under this TMDL.
The Choptank Watershed has two sites listed in the Site Investigation and Restoration Section
database. Both of these sites are Voluntary Cleanup Program (VCP)
Each of the sites is sampled through the program listed above for a consistent suite of environmental contaminants. These contaminants are broadly classified as Volatile Organic Compounds (VOCs)
, Semi-Volatile Organic Compounds (SVOCs)
, Polychlorinated Biphenyls (PCBs)
and Metals as listed using USEPA and DNREC defined standards. When sites are adjacent to water bodies sediment samples are collected to assess potential impact from a site on the health of the waters.
If you would like to view reports for any of the sites in the SIRS program please follow the link theDNREC Environmental Navigator
to search by map for the Choptank Watershed.
The majority of the streams within the watershed have drainage ditch characteristics due to the surrounding agricultural practices. The exceptions are found near and downstream of Mud Millpond, which is more forested. Soil types in the watershed include predominantly Pocomoke-Fallsington-Sassafras soil associations described by the Natural Resources Conservation Service as "very poorly drained, poorly drained, and well drained soils that have a moderately permeable subsoil of clay loam to sandy loam," and Fallsington-Sassafras-Woodstown associations described as "poorly drained to well drained soils that have a moderately permeable subsoil of sandy loam to sandy clay loam."
Total Maximum Daily Loads (TMDLs) Analysis for Chesapeake Drainage Watersheds, Delaware: Chester River, Choptank River, and Marshyhope Creek
Total Maximum Daily Loads (TMDLs) Analysis for Chesapeake Bay Drainage Basin, Delaware: Chester River, Choptank River, Marshyhope Creek, Nanticoke River, Gum Branch, Gravelly Branch, Deep Creek, Broad Creek, and Pocomoke River Watersheds
Assessment Report of Delaware's Chesapeake Basin
Delaware's Chesapeake Bay Watershed Implementation Plan (WIP)
U.S. EPAs Chesapeake Bay TMDL documents