For most of its length, the Hutt is a shallow and sometimes braided river in a wide rocky bed, but in the Kaitoke gorge the river flows directly over bedrock, and approaching the mouth at Petone the river is narrower and the banks steeper. The larger populated areas in Upper Hutt and Lower Hutt are protected from flooding by stopbanks and introduced willow trees, as is common in New Zealand. The regular flooding of Lower Hutt resulted in highly fertile land and prior to the building of state housing by the first Labour Government starting in 1937, there were many market gardens in Lower Hutt.