Mildura - Lock 11
Designed and built in the 1920s and 1930s to provide pools for irrigation, the Lock now allows paddleboats, houseboats and recreational craft to cruise the river year-round regardless of water levels.
Lock 11 is a concrete chamber with four steel lock gates. The lock is filled by opening four butterfly valves upstream. Water enters the lock chamber via two tunnels, accommodating approximately 4.5 megalitres.
How a lock works? - For a boat to pass downstream through the Lock, the water inside the chamber must be at the same level as the top weir pool, to allow the gates to open. The top gates are opened by hydraulic powered arms to allow the boat to enter. The gates are closed behind the boat and the water in the lock chamber is released by opening large hydraulically operated butterfly valves. The butterfly valves are only slightly smaller than an average house door.
Water flows from the lock chamber, via tunnels, to the weir pool below. As the water level in the chamber drops, the boat is lowered with it, until equal to the level of the lower weir pool. The bottom gates are then opened and the boat continues on its way. The water levels in locks are raised and lowered entirely by gravity; no pumps are used.
To travel upstream the reverse occurs. After the boat enters the lock chamber and the gates are closed behind it, valves are opened above the upstream gates to fill the chamber, via tunnels from the top weir pool. Water enters the chamber from the tunnels through ports spaced along the bottom of each wall.
This is to distribute the inflowing water to minimise turbulence in the lock chamber as it fills. When the water level in the lock chamber is equal to the weir pool, the gates can be opened and the boat can proceed.
It takes only 7 minutes to empty or fill the lock chamber but it normally takes 15 to 20 minutes to pass a boat through the lock. Six to eight medium houseboats can be accommodated in one lockage.
Opening Hours:
The Paddle Steamer Melbourne passes through the lock up to 1,000 times a year.
The times when the Paddle Steamer passes through the lock can be checked with the Information Centre. Typically it is around 11.30am and 12.30pm.
Location
Lock 11, Mildura 3500 Map
