The concrete round bunker is located at Remic Rapids.
The structure blends seamlessly with its environment. Its a beautiful place to take pictures and a unique building to visit.
What is it doing here?
We looked online and found multiple answers. Some people suggested it might be Ottawa's first nuclear reactor, a secret military bunker or a Hydro Station.
The truth of its function came from Andrew King a local researcher and writer on everything Ottawa/Historical.
He suggested that "SLOWPOKE a nuclear reactor" was in fact located at Tunney’s Pasture. Slowpoke was not located were the bunker at Remic Rapids sits but rather further north at 20 Goldenrod Avenue.
The following historical information was written by Andrew King and provided by Ottawa Rewind.
"It was constructed as a commercial testing reactor to determine its feasibility. This nuclear reactor was in full operation after it reached critical mass in 1971 until 1984 when it was then moved to another test site located in Kanata, later decommissioned in 1992."
"The concrete bunker that remains on the shore of the Ottawa River directly opposite the old nuclear reactor site was built at the same time as the reactor in 1969-70. It was built to facilitate the increased “cooling” needs of Tunney’s Pasture, one of them you could speculate being the addition of a small nuclear reactor."
"A 1969 November 11 Ottawa Journal article describes in detail the construction of the bunker and a trench used to contain a pipeline to provide this cooling water to Tunney’s Pasture. A 3,000 foot long pipeline was placed in an underground trench that ran from the Ottawa River bunker building to Tunney’s Pasture to provide, as the article states: “river water which will be used for condensing in the air conditioning system.”
"The concrete bunker built in 1970, just before the nuclear reactor began operation, housed a pumping station that provided a 35,000 gallons per minute water intake from the Ottawa River through a 42 inch diameter pipe underneath the Parkway over to Tunney’s Pasture. A current satellite image of the area clearly shows the trench line from the bunker to Tunney’s Pasture."
"The pipeline would then return used water back to the Ottawa River at a temperature 8 degrees warmer. The pumping station concrete structure and the pipeline was built at a cost of $2.5million and was constructed in co-operation with the NCC who owned the land the project was built on. The NCC at the time re-assured Ottawa motorists the construction of the bunker and pipeline would not disrupt traffic as it crossed the Parkway saying “We Insisted that they install four lane detours,”
"The pumping station bunker and pipeline were finished in 1970 and the reactor began operating a year later. Whether or not the bunker pipeline bringing cooling water to Tunney’s Pasture was directly related to the addition of a nuclear reactor remains speculation but it is interesting to note the proximity and similar timeline of both projects."
Therefore the bunker is actually a water pumping station for the Tunney’s Pasture complex.