The natural entrance to the lakes was unreliable and often dangerous. After much agitation, work began in 1872 to cut an artificial entrance, west of the natural entrance. Work on the "New Entrance" proceeded slowly and in 1876 was abandoned. Sir John Coode, renowned harbour engineer, advised on improvements but work did not resume until the early 1880s. In 1889, the new entrance was prematurely opened when a severe storm broke through the remaining sand hills. The natural entrance quickly silted up.

The Mitchell River Silt Jetties are an unusually long, thin landform in the Gippsland Lakes region in Victoria, Australia. A type of digitate delta, they have been formed over thousands of years by sediment deposition from the Mitchell River during periods of low water flow and subsequent wash-through during periods of high water flow. The long narrow banks of silt thus formed extend more than eight kilometres east into Lake King. The south bank is navigable by car from Eagle Point through to the very easternmost tip at Point Dawson. The Silt Jetties have been eroding since the early 1900s, soon after the permanent entrance to the Gippsland Lakes introduced sea water that killed protective shoreline vegetation. In 1919 a break cut through the northern Silt Jetty and by 1970 their land area was reduced by 45 percent. Works are being undertaken to preserve them. Farming on the jetties has ended and they are used for recreation. The jetties are listed on the Register of the National Estate.