River in the Sky

Built with expansion joints every 80 feet in its shell, the aqueduct soon developed persistent leaks and deteriorating concrete that demanded decades of repair. In 1916 and 1917, crews tightened, repacked, cleaned, and replaced metal bands at the expansion joints as the company tried to stop water from escaping, but leakage remained so heavy that one man later recalled riding his pony there as a child on hot summer days to enjoy the shade and waterfalls beneath it. The CPR experimented with several kinds of joints and found that V-shaped galvanized metal joints that moved like an accordion worked best, replacing the original copper joints over a period of years and waterproofing them regularly, before later replacing those galvanized joints with copper V joints beginning in the 1950s. Workers also repeatedly repaired the shell itself, patching crumbling concrete inside and outside and testing waterproofing coatings, mainly oil- or tar-based products, until gunite proved most effective; in 1926 the CPR reported guniting over 12,000 square feet inside the bowl and 112 places on the outside, although a 1961 report said that while a gunite layer applied about 25 years earlier remained in good condition, the concrete beneath it did not. At the same time, alkali in the dry soil attacked the concrete pedestals from the start, prompting repairs in 1917, replacement of concrete in 31 pedestals in 1918, and continued work year after year.

Alberta · Canada