The drought during the
Dirty Thirties prompted the construction of two dams, the
Gardiner Dam and
Qu'Appelle River Dam, along the
South Saskatchewan River, creating
Lake Diefenbaker. The Gardiner Dam was built along the course of the river while the Qu'Appelle River Dam was built to allow for water from Lake Diefenbaker to flow into the
Qu'Appelle River. A series of gravity-fed
aqueducts and reservoirs originating from Lake Diefenbaker were also built to supply water to the areas south-east of
Saskatoon, with Blackstrap Lake being the largest reservoir. Blackstrap North and Blackstrap South Dams were constructed in 1967, and are operated by the
Saskatchewan Water Security Agency.{{cite web The aqueduct, or canal, that feeds Blackstrap Lake originates at Lake Diefenbaker and passes through two other man-made reservoirs en route. The aqueduct starts at Gardiner Dam and heads south paralleling the South Saskatchewan River. East of the town of
Outlook, and just south of the village of
Broderick, the aqueduct flows into
Broderick Reservoir. From there, the canal meanders in a north-easterly direction until it meets
Brightwater Reservoir. From Brightwater Reservoir, the canal heads straight north towards
Indi Lake. passing to the east of it and then under Highway 11 and into Blackstrap Lake. A canal exits the north end of Blackstrap Lake at the North Dam and supplies water to other reservoirs, such as
Bradwell Reservoir and Zelma Reservoir. File:Blackstrap South Dam 01.jpg|Blackstrap South Dam File:Blackstrap South Dam 02 aqueduct.jpg|The Aqueduct that feeds Blackstrap Lake File:Blackstrap South Dam 03.jpg|Blackstrap Lake inflow from the aqueduct, near South Dam == Local communities ==