Graphic by Bryan Christie
“There it is. Take it.” So said famed engineer and LADWP director William Mulholland when fresh water spewed down the Los Angeles Aqueduct cascades the first time on November 5, 1913. Propelled solely by gravity along its 233-mile journey from the Sierra Nevada Mountains to the Newhall Pass, the water nourished a fledgling city and nudged it to grow. The aqueduct cost $22 million, took five years to complete, and was awash in corruption, but on that opening day the town was baptized.
1. The 1913 Penstock
Nearly every inch of the original 1913 steel pipe is still in use. Pipe was purchased by the ton in the early 1900s. The aqueduct’s diameter tapers and expands throughout, a visual record of Mulholland’s effort to stay on budget. The 1913 penstock measures up to 99 inches across. In other areas the pipe is so wide, you can drive a car through it.
2. The 1913 Cascades
The original cascades are approximately 35 feet wide and 450 feet long. About 60 miles of the aqueduct is made up of open channels, which were cheaper to build than laying steel pipe.
3. The Control Structure
This hollow cylinder regulates the flow of water to the power plant below. The 208 megawatts generated by the aqueduct account for 2.5 percent of the electricity used in Los Angeles. In 1913, it was responsible for 100 percent of the city’s power.
4. The 1970 Cascades
A familiar sight to drivers on the 5 freeway, this feature is 15 feet wide and 1,600 feet long. It was completed in 1970 as part of a second aqueduct, which begins at the Haiwee Reservoir, 60 miles south of the first aqueduct.
5. The Blocks
The inner surfaces of both cascades are lined with small cement blocks that dissipate the energy of the water. If the liquid moves too fast, its erosive effect increases, putting the structure at risk. Slowing it down also makes it less likely to splash out of the channel.
6. The Water
The speed of the water in the aqueduct varies between 1 and 2.5 miles per hour. It takes between five days and three months for the water to reach the cascades after it leaves the Owens River.