Mispillion River

Watersheds of the Delaware Bay & Estuary Basin
Appoquinimink River | Army Creek | Blackbird Creek | Broadkill River | C&D Canal East | Cedar Creek | Delaware Bay | Delaware River | Dragon Run Creek | Leipsic River | Little Creek | Mispillion River | Murderkill River | Red Lion Creek | Smyrna River | St. Jones River

The Mispillion River is located in southeastern Kent County and northeastern Sussex County. It forms the dividing line between Kent and Sussex counties. The Mispillion River flows in a generally easterly direction and forms for its entire length the Kent - Sussex County line, approximately 20 miles in length. There are nearly 70 miles of waterways plus several lakes and ponds in the watershed. There are four major water bodies in this watershed: Blairs Pond, Griffiths Lake, Haven Lake and Silver Lake. The watershed drains approximately 76 square miles. The headwaters of the Mispillion River origniate several miles inland and the river flows to the east where it drains into Delaware Bay.
Land Uses
The two major urban areas are Milford and Houston. Major land use in the area consists of agricultural lands and wetlands.
Water Quality
Please go to the Land/Ocean Biogeochemical Observatory (LOBO) site to see the latest real-time water conditions at the mouth of the Murderkill! This station represents the state-of-the-art in water condition and quality monitoring.
The Mispillion and Cedar Creek watersheds in this wetland assessment straddle southeastern Kent County and northeastern Sussex County, Delaware and cover 128 square miles of land with all its waters draining eastward into the Delaware Bay. The overall landscape shows the tell-tale signs of a rich history where gristmills, sawmills and shipbuilding once flourished.

Today the scenery is dominated by agricultural fields, wetlands, and developments. Wetlands in the Mispillion watershed make-up approximately one-quarter of the land, and are a great resource for protecting Delaware, but unfortunately, they are not able to function to their fullest potential in this watershed. Mispillion watershed wetlands are in fair condition, receiving a C as its overall grade. It has lost approximately 19% of its original wetlands since the early 1700s, mainly due to conversion of land to agricultural fields or development.

Tidal (C), riverine (C-) wetland types were assessed and graded (grade in parenthesis) in this watershed. The most common stressors to these wetlands were forest harvesting, invasive plant species, storm water inputs, excavation, filling, and ditching in the wetland, and development, agriculture, and roads in the lands surrounding the wetland (buffer). The complete reports and data for this assessment are available online.
Nutrients and Bacteria
The designated uses for the Mispillion include primary recreation, secondary recreation, fish, aquatic life and wildlife, industrial water supply, and agricultural water supply in freshwater segments. There is one point source (Baltimore Aircoil Milford Plant) and one former point source (Sea Watch International) found in the Mispillion River watershed. There are nutrient and bacteria TMDLs for the Mispillion watershed which require an 88% nitrogen reduction in King's Causeway Branch and 57% in the rest of the watershed, an 88% phosphorus reduction in King's Causeway Branch and 57% in the rest of the watershed, and a nonpoint bacteria reduction of 87%.
The Mispillion River Watershed has twelve sites listed in the Site Investigation and Restoration Section database. Five sites are state-fund lead (HSCA) sites, four sites have undergone a preliminary assessment / site inspection (PA/SI), and two sites are listed as Formerly Used Defense Sites (FUDS) and one site in the 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), Pesticides, 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 the DNREC Environmental Navigator to search by map for the Mispillion River Watershed.
Geology and Soils
Tidal influences affect the lower Mispillion up to the eastern edge of the City of Milford. Land in this watershed may be generalized as level to sloping with soils being characterized as having few drainage limitations and being of high agricultural productivity.
Cultural Resources
The Misipillion Lighthouse is a point located at the mouth of the river. It contains several wharfs used chiefly by fishing party boats and local oystermen.
Further Resources