Authorities in the northwest are on standby in case of further flooding after the Met Office issued a yellow weather warning for rain in Northern Ireland.
“Given the recent wet conditions, there is the possibility of localised flooding of homes and businesses as well as susceptible roads,” a Met Office spokesperson said.
The alert - which warns of the potential for heavy showers and isolated thunderstorms - is in place until 11pm on Friday.
Almost 500 homes were flooded and major roads blocked in Derry and Tyrone after “unprecedented” heavy rain fell on Tuesday night.
All main routes which had been closed because of the flooding have now reopened.
Flood response agencies including the Police Service of Northern Ireland (PSNI), NI Fire and Rescue Service, the Department of Infrastructure (DoI) Rivers and Roads, NI Water and Derry City and Strabane District Council (DCSDC), which are involved in the cleanup operation, say they are ready to respond to any further flooding.
More than 8,000 sandbags have been issued since Tuesday.
“Given pre-existing saturation levels and ground conditions across some Western/North Western areas in particular, the increased risk of heavy showers could lead to some localised flooding,” a spokesperson from the DoI said.
“Staff from all agencies are on the ground monitoring the situation, including latest weather reports, and ready to respond if necessary.”
Flooding Help Centres in the worst affected areas, in Eglinton and Drumahoe in Co Derry, remained open on Friday to provide advice and access to emergency supplies of donated food, clothing and cleaning products.
Technical officers from Derry and Strabane and neighbouring councils have carried out 300 visits to flooded properties.
A spokesperson from DCSDC said applications for the emergency relief fund - which provides up to £1,000 to cover emergency repairs to flooded properties - had been priorities in order to make payments available as quickly as possible.
“The teams will continue to visit homes across the council area today and over the weekend to inspect properties and process the assessment forms.
“Grant payments have already been issued and will continue to be over the Bank Holiday weekend,” the spokesperson said.
“The two flooding help centres set up at the YMCA in Drumahoe and the Eglinton Community Centre have been busy since Wednesday providing advice and assistance to those affected by the floods.
“The centres will continue to remain open from 8 am to 10pm daily with representatives from various agencies in attendance to offer advice and assistance.”
Council community service staff as well as representatives from advice services are on site to provide practical advice and support.
Further help is also being provided by NI Water and the NI Housing Executive, which has offered to assist in cleaning homes and gardens, and by the Red Cross, which is managing donations from businesses, charities and the public.
"Officers have also been on site at other locations across the council area including Plumbridge, Newtownstewart and Castlederg to assess flood damage to properties there."
City of Derry Airport has now reopened following a clean-up of the terminal and runway by airport staff, the Rivers Agency and the PSNI.
The A5 Derry to Strabane road - which had been closed since Tuesday - has now reopened with a temporary speed restriction at Burndennett.
Twenty five roads which had been closed due to flooding have now been reopened, and all affected main traffic routes are now passable with care.
With water levels reduced, the roads that remain closed are mainly due to collapsed bridges or culverts, landslides, damaged road surfaces or debris washed onto the road, a DoI spokesperson said.
These roads are mainly in the Claudy and Drumahoe areas of Co Derry, and the Gortin and Greencastle areas of Co Tyrone.
“It is likely that some minor roads may be closed which the Department is unaware of at present as efforts have been focused on the main road network however all roads will be inspected in the coming days,” the DoI spokesperson said.
“It is also possible that some further roads may have to be closed following inspection in the interests of road safety.
“Work is continuing over the bank holiday weekend to assess and repair damage to the roads and rivers impacted by this flooding.
“Road users are reminded to adhere to road signs and any temporary traffic lights, to avoid roads affected by flooding if possible and to take care driving.”
