The Susquehanna River watershed comprises 43% of the Chesapeake Bay watershed. The Middle Susquehanna watershed is 3,771 square miles of land located entirely within Pennsylvania. As a whole, the Susquehanna River contributes roughly 50% of freshwater entering the Chesapeake Bay, and nearly 43% of its total pollution. The Susquehanna River has been named America’s Most Endangered River twice—once in 2005, and again in 2011. Overdevelopment, agricultural run-off, and water flow impairments are just some of the many threats to the Susquehanna River. (Based on Middle Susquehanna Riverkeeper.)
