The River

The Hillsborough River, part of the Greater Tampa Bay watershed, spans all or part of Pasco, Polk and Hillsborough counties. With its peaceful origins in the Green Swamp, the Hillsborough River is one of the most urbanized in all of Florida.
No matter where in the world you live, you are part of a watershed! A watershed is land where water flows toward a common body of water such as a stream, river, lake or ocean. The Hillsborough River watershed encompasses more than 675 square miles

The Green Swamp:
The beat of central Florida’s hydrologic heart lies between Tampa and Orlando in 560,000 acres of Florida backcountry called the Green Swamp. It is a complex mosaic of wetlands, mesic flatlands, and uplands. These natural systems provide diverse ecosystems and habitats for an array of wildlife. The relatively dense and impermeable aquifer located within the Green Swamp is generally shallow (close to land surface), which allows rainfall that infiltrates into the soil to mound or stack up at the surface. This creates a rather large reservoir of standing water that forms the headwaters of the Hillsborough, Withlacoochee, Ocklawaha and Peace rivers. With the highest groundwater elevation in the peninsula, the Green Swamp is a critical area for maintaining the flow of water to the Floridan aquifer system. The Green Swamp is one of the state’s most significant water sources. Its unique topography aids in flood protection and acts as a natural filter to provide quality water. Protecting the Green Swamp is vital to protecting the quality and quantity of Florida’s water supply.

Estuaries are areas where fresh water from inland sources mixes with salt water from the Gulf of Mexico or the ocean. Estuaries are considered the most productive of the earth’s ecosystem, providing valuable habitat, and filtering pollutants and sediments out of the water.
Tampa Bay is the largest open-water estuary in Florida, encompassing nearly 400-square miles and bordering three counties: Hillsborough, Manatee and Pinellas. The freshwater sources of the bay are distributed over a hundred small tributaries, rather than a single river.

Beginning the reversal of decades of unrestricted pollution, the bay was designated an estuary of national significance in 1988. The warm outfalls of power plants bordering the bay draw one out of every six endangered manatees to spend the winter. Equally significant is the role of the bay’s waters as nurseries for shrimp and crabs, as well as less commercial invertebrates. Seagrass provides nutrients and shelter for numerous animals and directly impacts water quality. Mangrove-blanketed islands in Tampa Bay support the most diverse colonial water bird nesting colonies in North America, from the familiar white ibis and great blue heron to the regal raddish egret – the rarest heron in the nation.

QuickFacts on Tampa Bay:
- On average, Tampa Bay is only 12 feet deep
- More than 200 species of fish are found in Tampa Bay
- Each square meter of bay sediment contains an average of 10,000 animals
- A single quart of bay water may contain as many ax one million phytoplankton
- More than four billion gallons of oil, fertilizer components, and other hazardous materials pass through Tampa Bay each year

Hillsborough River Facts:
- Head Waters: Green Swamp
- Total length: 60 miles
- Tributaries: Crystal Springs, Blackwatercreek, Flint Creek, Trout Creek, Cypress Creek, Curiosity Creek and Sulphur Springs
- Average fall: 1.4 feet/ mile
- Drainage area: 690 square miles
- Mouth: Hillsborough Bay
- Primary source of drinking water for the City of Tampa
- Decomposing plant materials and tannins stain the water dark (much like tea), which is typical of a blackwater river

These facts have been provided by
Southwest Florida Water Management District
Keep Tampa Bay Beautiful