CONTAINER storage owners in the New Territories have threatened traffic chaos by closing their land to lorry drivers, forcing them to park on roads. The warning came from the San Tin Container Vehicle Park Association following controversial legislation over the use of farmland for other purposes. Operators had received warning letters from the Government last year giving them three months to comply with the new regulations or face prosecution. Under the new legislation they must get permission from the Town Planning Board if the land is to be used for anything other than farming. The association's preparation committee spokesman, Wong Kam-sing said: ''We don't want to take any crucial action, but we will, if we have to, as a last resort.'' Drivers might be left with little choice but to park on the roadside causing traffic chaos. But association chairman Man Fu-wan said the group would hold a general meeting before taking any action. Chief Inspector Stephen Verralls said: ''We at first will issue tickets for drivers for illegal parking. If there is a major obstruction, we will come up with a contingency plan to deal with the problem.'' Mr Man said farmland had been used for parking purpose for more than five years. ''At first, there were about 2,000 containers and trailers about three years ago. But now there are over 5,000,'' he said. Mr Wong said the group had recently submitted applications to the Town Planning Board to use farmland for parking purposes. ''It will take about three months. However, we are optimistic that the Government will grant permission,'' he said.