The Hillsborough River watershed begins in the Green Swamp and travels south until it meets Tampa Bay.
The Hillsborough River watershed encompasses more than 675 square miles.
The Hillsborough River watershed includes parts of Hillsborough, Pasco and Polk counties.
There are four sub-basins within the Hillsborough River watershed: Blackwater Creek, Lake Thonotosassa/Flint Creek, Cypress Creek, and Mainstem (which includes the Upper, Middle, and Lower stretches of the river).
The watershed has two named springs, Crystal Springs and Sulphur Springs. Crystal Springs is a natural spring near Zephyrhills that is a major source of fresh, clean water for the Hillsborough River.
While the Hillsborough River is spring fed, it is primarily a blackwater river. A blackwater river drains pine flatwoods and cypress swamps and has dark, stained water from decomposing plant material.
The Hillsborough River is the most urbanized river discharging into Tampa Bay. It provides a substantial amount of freshwater flow, which is crucial for the salinity levels and habitat needs of Tampa Bay, Florida’s largest open water estuary.
The Hillsborough River is the primary source of drinking water for the City of Tampa.