By Jon Nazca and Miguel Pereira
RONDA, Spain / ALCACER DO SAL, Portugal, Feb 4 (Reuters) - Rivers and reservoirs in Spain and Portugal were on the verge of overflowing on Wednesday as a new weather front pounded the Iberian peninsula just a week after Storm Kristin left six people dead and thousands without power.
In southern Spain's Andalusia, 14 rivers and 10 dams were at "extreme" risk of overflowing, compounded by saturated ground from earlier storms this month, according to Antonio Sanz, head of the regional government's interior department.
Portugal raised its alert level to the maximum until at least Friday, with authorities warning several rivers were at high risk of flooding.
In Alcacer do Sal, a town 90 kilometres (55.92 miles) south of Lisbon, the Sado river overflowed its banks on Wednesday, flooding parts of the town.
"I've never seen anything like this, never. It's surreal. I have no words," said longtime local resident Maria Cadacha.
"The entire lower part of the city is flooded, the whole waterfront is inundated," said mayor Clarisse Campos.
"We have businesses flooded. We are monitoring people who live in those areas to determine whether it is necessary to evacuate them and move them to a safe place," she added.
In Spain, Andalusian authorities described the situation in the municipality of Grazalema as dire, with an overwhelmed sewage system leading to water gushing from homes. Television footage showed water flowing out of electrical sockets and workers drilling holes into walls to drain floodwaters. A house wall collapse in Ubrique, Cadiz, injured one person.
At least 3,500 residents were evacuated in Andalusia. Authorities cancelled classes across the region, warned residents to avoid unnecessary travel and deployed 1,200 emergency personnel and 400 military service members to assist in flood-prone areas. Emergency aircraft and helicopters were also called in to monitor critical zones.
"It's been raining like this for hours. The river has already overflowed, and people are very worried inside their homes. We are experiencing many power cuts," Jose Luis Castillo, who lives in Jimera de Libar, told Reuters.
Spain's state weather agency AEMET forecast continuous and intense rainfall in parts of Andalusia, central Spain, and Galicia in the northwest lasting through Saturday. It warned of possible landslides and damage to property and infrastructure.
Portugal's National Civil Protection service said water levels are likely to rise over the coming days and the armed forces have deployed 1,600 personnel, including marine teams with 35 inflatable boats, to rescue people from flood-hit areas.
(Reporting by Emma Pinedo and David Latona in Madrid, Sérgio Gonçalves in Lisbon; Editing by Sharon Singleton, Charlie Devereux, Nia Williams and Nick Zieminski)
