The roads minister has said that work has been completed that should prevent a repeat flooding of the Belfast's Broadway Underpass.
There was widespread criticism when the multi-million pound project was overwhelmed by 20ft of water last August trapping motorists.
But Sinn Fein's Regional Development Minister told the Assembly that after an independent inquiry measures were now in place that would have prevented the flooding.
A weekend of heavy rain caused nearby waterways to overflow, overwhelming the high profile roads scheme and sparking major controversy.
But the minister said new measures included the installation of an alarm system to provide early warning of any future floods.
"The results of the hydraulic model clearly show that the major cause of the flooding was a partially blocked screen at the Clowney Water inlet, in addition a section of embankment on the eastern side of the Clowney Water was breached and washed away during the flooding event," Mr Murphy said.
"It is evident that the river drainage system provided is compliant with the requirements of the contract.
"Measures have been implemented upstream of Broadway to intercept debris in the upper reaches of the Clowney Water before it reaches the Broadway System.
The minister said that the independent report on the incident made three main recommendations, which had now all been met.
The report had ordered that the banks of the Clowney Water be raised, that enhanced procedures to ensure public safety be implemented and that a model be used to assess the efficiency of the drainage system.
Mr Murphy said Rivers Agency had recently reassumed responsibility from the contractor for the Clowney/Blackstaff drainage system including the early warning system at the Clowney inlet.
Procedures have been established, he said, for notifying staff in the event that an alarm is triggered.
The minister said: "I am advised that Rivers Agency in partnership with all responsible authorities as required by the Floods Directive is currently carrying out a Flood Risk Study for Belfast.
"The information obtained from the modelling work will be used to inform the study and help to identify proposals to better assess and manage the overall risk of flooding."
© Press Association