Rainwater from above, groundwater from below: Constant flooding in sprawling Pikine, much of which sits on an old swamp, has wearied residents keen to vote for change in February polls.

Just outside Dakar, Pikine is a ticking time-bomb, warns opposition Mayor Aliou Diouck of the massive suburb of crumbling houses where unemployed men sit, waiting in the dry heat, which never seems to soak up the filthy pools of water.

Resident Sarr, about 60 years old, sits on the porch of his home, a small courtyard behind four walls in ruins. A swarm of grubby children play near a cesspool, trash floating in the reeds.

"I voted for (President Abdoulaye) Wade, I was disappointed. Now we are waiting impatiently for change, we turn to God," Sarr told AFP, vowing to vote on February 26.

He lives in Hamdallaye, a section of Pikine constantly battling floods caused by the rising groundwater level which affects some 350,000 people throughout Pikine and Guediawaye, worsening during the rainy season from June to October.

For many the floods symbolise the indifference of the authorities to the poor and the failure of Wade, 85, who is seeking a highly disputed third term after 12 years in power.

"I haven't voted since 2000 but this time I went to register," said Amadou Sow, 42, who describes himself as "without activity."

"I did everything to get my voter's card and told others to do the same."

Election posters are hard to find in Hamdallaye, where extended families are tightly packed behind faded walls, surviving on a small contribution from each person earned here and there at a stall or in a workshop.

Unemployment is rampant and infrastructure dilapidated or non-existent. Only the power supply has improved considerably in recent months.

"These floods have caused a degradation of habitat and public health problems in already-difficult living conditions," says Mayor Diouck.

With a total of 1.8 million inhabitants "the suburb has become a ticking time-bomb", he says, calling for a "coherent and ambitious rehabilitation plan."

"There has been much talk but little action. The expectations are enormous. The suburb is aware of the stakes of this election, all eyes are fixed on that hope."

Since 2009 local elections, the outskirts of the capital are largely in the hands of the opposition which controls 15 of 21 communes of Pikine and Guediawaye.

Diouck said Wade, who had been opposition leader for 25 years before his election in 2000, had "seduced with his populist speech".

"Here we no longer expect anything from the current government, we are sick of everything," said student Mohamed Sow, 22.

"In 12 years of power they have done nothing, we will simply try the others."

Badar Guei, who is retired, wants Wade to win.

"No one can replace him ... before the opposition was in power and they did nothing," he recalls.

Selling bread on the side of the road, Adama, an elderly woman with a toothless smile, remains hopeful.

"In 2000 Wade promised so much but nothing changed. This time we will also have promises, but we will go and vote for change anyhow."