Franklin’s geography is very much a product of its geologic past and falls into three well defined sectors. In the northeast the Hunua ranges, rising to 688 metres above sea level, are built of greywacke rock laid down over 200 million years ago. Apart from areas of easier country between the Hunua Ranges and the Hunua hills and in the Mangatawhiri valley, the land is steep and rugged -often covered with bush.
South of the Waikato River the geology is a mixture of greywacke, limestone, mudstone, sandstone and volcanic material that ranges from 2 to 195 million years old. Much of this country is also steep and rugged, although most has been cleared for farming.
The remaining sector comprises the north west portion of the District which is geologically very young. To the north and west the parent materials are conglomerates of sandstone and mudstone less than 20 000 years old. The south central area is volcanic in origin and of similar age.
Soil types
The soils of the central part of the District, from Bombay across to Waiuku and from Tuakau to Karaka, are the main source of Franklin’s prosperity. Enhanced by the relatively low frost levels they are well suited to the growing of a wide range of crops. Here is produced one third of the nation’s fresh vegetables. This is the most developed part of the District, containing the three largest towns and 71% of the population.
Major Transport Corridors
Franklin is bisected by State Highway 1, which runs from Runciman to Mercer and by the main trunk railway, which loops around through Pukekohe and Tuakau and has a spur line to the Glenbrook steel mill. State Highway 2 leaves SH I at Pokeno and heads toward Thames. The District is well served by nearly 1,600 Km of roading, over 80% of which is sealed.