THE base for three government departments as well as the headquarters of the prison service were forced to close on Friday due to a power failure.
And Parliament Buildings at Stormont is expected to operate on limited electricity supplied by a generator until Tuesday.
Dundonald House, where the Department for Agriculture (DARD) and the Northern Ireland Prison Service are based, as well as Craigantlet Buildings, which is home to the Department of Finance, were both closed yesterday.
Finance Minister Sammy Wilson reassured the public that the delivery of essential services would not be affected.
He confirmed that Dundonald House and Craigantlet Buildings are closed while the remaining buildings within the Stormont Estate – including Parliament Buildings – continue to operate on a limited power supply.
Mr Wilson said all business areas affected had initiated their business continuity plans to ensure essential functions and services are maintained.
“The situation is being closely monitored and Northern Ireland Electricity are assisting my department to resolve this situation as quickly as possible,” said the Finance Minister.
“Engineers have been and will continue to be on site over the weekend.
“I would like to take this opportunity to assure the public that all essential services provided by these departments remain unaffected as alternative arrangements have been made and business continues as normal.”
It is not known how long the departments will be out of these buildings for, but it is understood that the buildings may be out of use for up to three months.
The floods hit Northern Ireland – particularly Belfast – following sudden heavy and prolonged rain from around 6.30pm on Wednesday.
The unpredicted deluge sparked some of the worst flooding that Belfast has seen in recent years. Other areas badly affected included Lisburn, Dunmurry, Bangor and Cushendall.
And despite being on a hilltop, Stormont did not escape flood disruption. Yesterday it emerged that Parliament Buildings and several other government departments were without electricity.
The power cut yesterday was expected to last until next Tuesday. However, a spokeswoman for Stormont said that business would continue as usual on Monday and Tuesday.
It is understood that MLAs and staff will not be able to use computers or any other electrical equipment, while no hot food or tea or coffee will be available on Monday and Tuesday. The lifts will also be out of action.
A note circulated around one political party urged all support staff who did not need to be at Stormont on Monday not to go there as there is only a limited amount of electricity available.
MLAs have been urged to bring portable devices such as iPads.
In a statement a spokeswoman for the Assembly said: “Parliament Buildings has been affected by the recent flooding and as a result power supply to the building is very limited. However, plenary business will continue as usual next week (Monday, July 2 and Tuesday, July 3).”
Elsewhere, Dundonald Ice Bowl last night remained closed following the floods and the squash courts in the Robinson Centre are understood to be closed.
Meanwhile, the Met Office has forecast more rain early next week. Intermittent rain is expected this weekend with heavy rain forecast on Tuesday and overnight into Wednesday. However, there were no severe weather warnings in place yesterday.
Last night NI Water said it has stood down its incident team that was established in response to the flooding events on Wednesday evening.
A spokesman said staff remained on high alert and were ready to react if the situation changes over the weekend.
“NI Water is focusing attention and resources on providing assistance to those customers who were affected by sewerage-related flooding,” said a spokesman. “However, the organisation will be monitoring weather forecasts closely to ensure we can provide a prompt response to any situation which may arise over the weekend.”