activity occurs in restored estuary. Daily minimum flow begins December 31, 2007. The river today The Hillsborough River is home to many species, and several large bird rookeries exist. When local students reach sixth grade in Hillsborough County, they take a visit to the river for one to three days to learn about the ecosystem, watershed, and native Florida animals at a place called 'Nature's Classroom'. The Hillsborough River dam (originally built in 1895 and since rebuilt) at Rowlett Park creates a lake covering and containing of water, providing for the supply of water for the City of Tampa. The Hillsborough River was immortalized in 1973 by author Gloria Jahoda in her book River of the Golden Ibis. With the construction of the dam in 1945, the portion of the River above the dam to approximately Fletcher Avenue is where the City of Tampa is permitted to withdraw water to supply to its citizens and those in Hillsborough County. In addition, Tampa Bay Water is permitted to withdraw water from the River during "high flow" times and under specific conditions. The Southwest Florida Water Management District, the agency required by Florida law to protect and manage the waters in the state, authorizes the permits. With the establishment of the minimum flow of the upper and middle river by the Southwest Florida Water Management District in 2007 and its supporting Recovery Strategy, the City of Tampa and the District in partnership are implementing measures and projects to achieve the required flow in the lower river, while preserving the pristine nature of the middle and upper rivers. The river above the dam to roughly the 56th Street bridge passes through the neighborhood of Temple Crest. The river above the 56th Street bridge passes through the City of Temple Terrace and it is one of the many scenic portions of the river. The City has a river cleanup of its river portion twice a year. Hillsborough River State Park Hillsborough River State Park includes along the Hillsborough River in northeastern Hillsborough County. It supports many Floridian environments such as swamps and oak hammocks and many endangered species. The park's purpose is to preserve the "real Florida". Visitors to the park can participate in picnicking, camping, canoeing, hiking, fishing and swimming in a constructed pool. There is also a designated place to observe the river's class II rapids. It is one of the only