A tributary is a small stream or river that flows into a larger one. The more tributaries a river has, the bigger it gets. The Hillsborough River’s tributaries include: Big Ditch, Flint Creek, Tampa Bypass Canal, Indian Creek, New River, Two Hole Branch, Basset Branch, Hollomans Branch, Clay Gully, Cypress Creek, Trout Creek, Clear Lake, Moon Lake, and Lakes Thonotosassa, Hunter, Iola, Pasadena, King, and Padgett.

Tampa Bypass Canal

The Tampa Bypass Canal is a 14-mile waterway that connects the Lower Hillsborough Wilderness Preserve (LHWP) with McKay Bay. It was built as part of the “Four River Basins, Florida Project,” which was a major flood-control project sponsored by the U.S. Army Corps of Engineers after Hurricane Donna caused massive damage to southwest Florida in 1960. Designed and built in the 1960s and 70s, the Tampa Bypass Canal and flood-control structures provide flood protection for the cities of Temple Terrace and Tampa by diverting floodwaters from the Hillsborough River. The canal also is a water supply source for the City of Tampa.

Spanning 16,000 acres, the primary purpose of the LHWP is to store floodwaters diverted from the Tampa Bypass Canal and provide a source of water supply. Located within the LHWP is the Morris Bridge wellfield where Tampa Bay Water manages 20 wells that pump water from the Floridan aquifer for the City of Tampa.

City of Tampa

The preserve also is important for the conservation of natural resources as it inhabits one-fourth the River’s length. The riverine forests and pine flatwoods are managed by the District and Hillsborough County to promote biodiversity. The forested wetlands are essential for filtering rainwater before it flows into the river and for storing floodwaters. And, significant ecological features include a wood stork rookery, a sawgrass marsh, a sphagnum bog and two sinkholes. The LHWP also is a very popular site for various recreational opportunities.

Lake Thonotosassa

Lake Thonotosassa is the largest natural lake in Hillsborough County with a surface area exceeding 800 acres. As one of the few natural lakes in the area with public access, it’s popular for recreational use.

Lake Thonotosassa

Since water from the lake discharges into the Hillsborough River, a public water supply, and because the lake’s water quality is so poor, the District and several cooperators have completed multiple projects to treat stormwater before it enters the lake. One significant project completed in 1999 is the Lake Thonotosassa Marsh Restoration Project, where a 51-acre marsh system was designed to treat incoming water from a creek before it discharges into the lake.