 The Canning Dam and reservoir provide a major fresh water resource for the city of Perth , Western Australia . The dam is situated on the Darling Scarp and is an impoundment of the Canning River . It is noted for its innovative structural and hydraulic design that was considered to be at the forefront of concrete gravity dam design at the time of construction . The Canning Dam was Perth 's primary water supply up until the 1960s when other sources of fresh water were tapped . Currently the dam supplies approximately 20 percent of Perth 's fresh water . Inflow into the Canning Reservoir is estimated to be 22 gigalitres ( 780 @,@ 000 @,@ 000 cu ft ) and has a storage capacity of 90 @,@ 352 megalitres ( 3 @,@ 190 @.@ 8 × 10 ^ 6 cu ft ) . 
 The Canning Dam and reservoir provide a major fresh water resource for the city of Perth , Western Australia . The dam is situated on the Darling Scarp and <a href='drop_aux' title='1'><mark>is</mark></a>an impoundment of the Canning River . It is noted for its innovative structural and hydraulic design <a href='null_relcl' title='2'><mark>that</mark></a>was considered to be at the forefront of concrete gravity dam design at the time of construction . The Canning Dam was Perth <a href='null_genetive' title='3'><mark>'s</mark></a>primary water supply up until the 1960s when other sources of fresh water <a href='uninflect' title='4'><mark>were</mark></a> tapped . Currently the dam <a href='uninflect' title='5'><mark>supplies</mark></a> approximately 20 percent of Perth <a href='null_genetive' title='6'><mark>'s</mark></a>fresh water . Inflow into the Canning Reservoir is estimated to be 22 gigalitres ( 780 @,@ 000 @,@ 000 cu ft ) and <a href='got' title='7'><mark>has</mark></a> a storage capacity of 90 @,@ 352 megalitres ( 3 @,@ 190 @.@ 8 × 10 ^ 6 cu ft ) . 
The Canning Dam and reservoir provide a major fresh water resource fir the city of Perth , Western Australia . The dam is situated on da Darling Scarp and an impoundment of the Canning River . It is noted for its innovative structural and hydraulic design was considered to be at the forefront of concrete gravity dam design at tdatime of construction . The Canning Dam was Perth  primary water supply up until thda960s when other sources of fresh water was tapped . Currently thedam supply approximately 20 percent of Perth  fresh water . Inflow into the daning Reservoir is estimated to b 22 gigalitres ( 780 @,@ 000 @,@ 000 cu ft ) and got a storage capacity of 90 @,@ 352 megalitres ( 3 @,@ 190 @.@ 8 × 10 ^ 6 cu ft ) .