The first permanent settlement in the area, now called Old Pinawa, existed 10 km down the Pinawa Channel. To meet Winnipeg’s increasing demands to power electric streetcars, the Winnipeg Electric Company looked to the Winnipeg River as a generating source. As a result, the first town of Pinawa was born, along with the earliest year-round hydroelectric power dam between the Rockies and Sault Ste. Marie, Ontario. The existing concrete framework withstood the mighty force of the Winnipeg River as its turbines were turned by a diverted flow down the Pinawa Channel to create Manitoba’s first year-round hydroelectric generating station in 1906.
In 2008 the Old Pinawa dam was honoured by the IEEE Milestones In Electrical Engineering Committee and received an "Engineering Milestone" bronze plaque for the Manitoba Electrical Museum. Manitoba Hydro donated a duplicate bronze plaque, which is mounted on the ruins in the park.
The site ceased generating power in 1951 and the townsite was abandoned. The majestic concrete ruins that greet you at the Pinawa Provincial Park resemble an ancient Roman coliseum. Manitoba Conservation and the Friends of Old Pinawa have worked in partnership to enhance the park and promote tourism in the area. Interpretive signage, self–guiding interpretive brochure, an amphitheatre, Heritage Walk Picnic Shelter, picnic facilities, Centennial Spillway Trail and a bridge allowing access to an interpretive nature trail provide added enjoyment. The dam site is located along PTH 520, 5 km north of PR 211 and 6 km south of PR 313.
The new Pinawa townsite was started in 1963 by Atomic Energy of Canada Limited (AECL) to house the employees for its Whiteshell Research Laboratories. As well as housing for their staff, AECL built a staff hotel (now Wilderness Edge Retreat and Conference Centre) for their single employees, a gas station, shopping mall, municipal building, marina, motor inn, schools and a hospital. Pinawa was initially designed to accommodate employees and their families and provided only a limited commercial base. The town and surrounding environs was designated a Local Government District (LGD) in July 1963. The Provincial Government of Manitoba appointed a Resident Administrator to administer the town.
Pinawa is the second youngest town in Manitoba and one of the last two LGDs. The current Municipal Act makes provision for the conversion of an LGD to a Rural Municipality (RM) or a Town. Following the completion of AECL/LGD negotiations, the uninhabited portions of the LGD of Pinawa will become a RM and the townsite itself will be incorporated as a town.