Report: Southern New Castle County Priority Watershed Strategy

This report provides a recommended priority watershed strategy for the streams in southern New Castle County, Delaware.  This strategy is designed to be consistent with the following:

  1. Total Maximum Daily Loads (TMDL) and Pollution Control Strategy (PCS) issued for the Appoquinimink River watershed by the USEPA and the Delaware Department of Natural Resources and Environmental Control (DNREC)
  2. Environmental protection articles of the New Castle County Unified Development Code (UDC)
  3. 2007 New Castle County Comprehensive Development Plan Update, July 31, 2007

The priority watershed strategy concludes that the resource protection level (RPL) standards of the New Castle County UDC, if imposed properly on new development proposals, are adequate to protect water resources and natural resources in southern New Castle County at full build-out with current zoning in effect. The contiguous chain of watersheds lining the Chesapeake and Delaware Canal, the Delaware Bay coast, and the Blackbird forest and wetland complex with low impervious cover and large amounts of forests, wetlands and riparian buffers create an emerald ring around the rapidly growing towns of Middletown, Odessa, and Townsend (MOT) in southern New Castle County.  These green watersheds should be protected from over-development by acquiring more open space and conservation easements, thus creating an unbroken ring of conservation open space-a green belt-around the periphery of the MOT village core.

USEPA Grant

The New Castle County Department of Land Use received a United States Environmental Protection Agency (USEPA) Wetland Program Development Grant to protect and enhance wetlands and riparian corridors in southern New Castle County, Delaware.   The County retained the University of Delaware Water Resources Agency in the Institute for Public Administration to assist with a watershed-based approach to protect existing wetland and riparian corridors while being consistent with the following federal, state, and local programs:

  • A watershed-based stormwater utility program recommended by the April 2005 Governor’s Surface Water Task Force report and a December 2005 resolution forwarded by the County Executive for consideration by New Castle County Council.
  • USEPA National Pollution Elimination Discharge System (NPDES) Stormwater Permit Part II by applicants New Castle County and the Delaware Department of Transportation.
  • Appoquinimink River Total Maximum Daily Loads (TMDL) imposed by the Delaware DNREC in accordance with Section 305b of the federal Clean Water Act (DNREC, 2004).
  • Appoquinimink Watershed Implementation Plan authored by the Center for Watershed Protection and being implemented by the Appoquinimink River Association (Center for Watershed Protection, 2004).
  • 2007 New Castle County Comprehensive Development Plan Update, July 31, 2007.
  • New Castle County Unified Development Code (UDC) environmental standards.

Objectives

  1. Provide a new subwatershed framework to assist New Castle County planners during development plan review to minimize environmental and water resources impacts in southern New Castle County.
  2. Evaluate the adequacy of the New Castle County Unified Development Code (UDC) resource protection level standards in protecting water and environmental resources in southern New Castle County at the future full build -out condition under current zoning.
  3. Recommend priority watersheds for protection in conformance with the New Castle County Unified Development Code and the 2007 New Castle County Comprehensive Development Plan Update using indicators such as impervious cover, forests, wetlands, protected open space, and riparian buffers.