The Christina Basin is a diverse, suburbanizing watershed situated within the Delaware River Basin. Most of the Christina Basin is occupied by three land uses in similar proportions—Urban/Suburban (34%), Agricultural (31%), and Open Space/Forested Lands (35%). The watershed is well known as the home of two Revolutionary War battles, the Brandywine school of art, the largest concentration of mushroom growers in the U.S., and the corporate home of chemical and credit-card industries. In addition, the watershed is the home for over one-half million people near the Cities of Newark and Wilmington, Del., and West Chester, Downingtown, and Coatesville, Pa.
Due to its pastoral quality and proximity to job centers, the Christina Basin is undergoing development pressure. The Christina Basin is largely a rural yet suburbanizing watershed, which indeed is a microcosm of many small watersheds in the Mid-Atlantic region. The Christina Basin occupies 565 square miles and includes four major watersheds: Brandywine Creek (325 sq. mi.), Red Clay Creek (54 sq. mi.), White Clay Creek (107 sq. mi.), and the Christina River (78 sq. mi.). The Basin includes 38 sub-watersheds ranging from 4 to 33 square miles.
The streams of the Christina Basin flow through three states – Pennsylvania (400 sq. mi./71%), Delaware (157 sq. mi./28%), and Maryland (8 sq. mi./1%) and include five counties; Chester (388 sq. mi./69%), Delaware (9 sq. mi./2%), and Lancaster Counties (3 sq. mi./1%) in Pennsylvania; Cecil County in Maryland (8 sq. mi./1%), and New Castle County in Delaware (156 sq. mi./28%).
Within the five counties, the Christina Basin includes 57 local municipal governments and large towns such as Wilmington, Del., Newark, Del., Avondale, Pa., West Grove, Pa., Kennett Square, Pa., Downingtown, Pa., Coatesville, Pa., and West Chester, Pa.