The history of the Hillsborough River dam

old black and white photo of hillsborough river damNovember 2022 – The “middle river” has a long and interesting history. The middle river through Temple Terrace and into the City of Tampa didn’t always include a dam, and that dam wasn’t always used for water supply. During much of the 1800s, the Hillsborough River existed in a natural wild state. In 1886, the first streetcar in Tampa was built powered by steam. A new company, the Consumers Electric Company, expanded and electrified the streetcar network and purchased and expanded a small timber crib hydroelectric dam first built to power a sawmill.  To power the growing streetcar network, the Consumer Electric Company constructed a new dam further down the river, the site of the current dam, between 1896-1897.

Consumers Electric became embroiled in a controversy with cattlemen after the company built the 2,500-kilowatt hydroelectric plant and a dam across the Hillsborough River. The dam flooded several hundred acres of land previously used for grazing. The dam was blown up with dynamite in 1898, a year after it was completed. Four men were tried for the crime but were acquitted.

Lacking the funds to finance the rebuilding of the dam, Consumers Electric sold its system to the newly founded Tampa Electric Company. The dam was rebuilt in 1899 but continued to be controversial. In 1916 there were new but failed attempts to blow up the dam. The dam generated electricity until high water from a hurricane disabled the dam and facility in 1933. Meanwhile, the City of Tampa entered the water business in 1923. At the wide middle section, intake pipes penetrate the river and extract water for city use. The current dam forms a 1,300-acre reservoir holding 1.6 billion gallons of water.

The dam was renovated in 1925, and Tampa was using water behind the dam by 1926. In 1944, the city purchased the dam from Tampa Electric and completed a dam expansion in 1945. Since then, the middle river’s impounded water behind the dam has been the primary source of potable water supply for the City of Tampa’s citizens. When water is too low in this impoundment to capture for supply, the City of Tampa purchases wholesale potable water from the Tampa Bay Water regional water wholesale agency.

More recently, Tampa is currently considering a new small-scale hydroelectric facility for the dam.

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