That seasonal phenomenon - falling autumnal leaves - is thought to be responsible for much of the flash flooding experienced in the Dublin city over the past two days.
Heavy downpours, falling almost continuously since Sunday morning, coupled with gale force winds, led to a glut of fallen leaves blocking roadside shores or "gullies" and constricting the drainage system, according to Dublin City Council.
"Leaves are an additional problem at this time of year, particularly with all the rain and wind we've been having," deputy Dublin city engineer Mr Battie White said.
"We can't stop the leaves falling off the trees, but they do block the gullies very quickly. There are about 60,000 gullies in the city, so we do have to try to deal with it."
In addition to its normal street cleaning operation, the council has deployed gully cleaning crews, in both a preventative and emergency capacity, to cope with the leaf falls, Mr White said.
"Generally the system can cope with normal or exceptional rainfall but it does have its limits," he said.
While much of Dublin remains at risk from flooding, the areas of Portmarnock, Clontarf and the North Circular Road, to the north of the city and Old Kilmainham, Kimmage, Crumlin and Harold's Cross to the south were worst affected over the past two days.
A number of roads around the city were impassable or barely passable last night, according to AA Roadwatch. Mount Brown, Old Kilmainham, was under three feet of water and had to be closed as passing motorists were forcing water under the doors of houses.
Shortly before 5 a.m. yesterday, Dublin Fire Brigade rescued two people who had become trapped in their car in Baskin Lane, Portmarnock. In all, the Fire Brigade attended 20 flooding incidents from Sunday evening to yesterday morning.
This is the second week in a row Dubliners have found themselves battling against rising flood waters. A short burst of torrential rain over the city on Sunday last week led to localised flooding in the Dublin 4 and Dublin 6 areas. While this week's rainfall was not as dramatic, it has been more persistent.
"The previous rainfall was very intense and there were huge differences in amounts of rainfall across the city. This time the rain has not been as heavy, but it's been spread over the whole city and it's been raining almost constantly since 9 a.m. on Sunday morning," Mr White said.
