A massive cleanup effort is underway on the North Shore after heavy rainfall caused creeks to overflow, flooding streets, houses and a school overnight.

Lynn Valley, Deep Cove and other communities in the region were hit hard, with more than 80 millimetres of rain pounding the North Shore overnight.

District of North Vancouver Mayor Richard Walton said resulting flooding was reminiscent of a deadly mudslide in 2005 that killed a North Vancouver woman and destroyed two homes.

IN PICTURES: Widespread flooding after rain ravages North Shore

“When the heavy rain comes down obviously we’re sitting upright and very, very alert,” Walton said. “We have experience that we’ve learned from, but do not wish to repeat.”

The rain fell hard and fast, leading to floodwater so strong that crews couldn’t do much after receiving calls from distressed residents just before 10 p.m. Monday.

Every available fire truck from the District as well as the City of North Vancouver and West Vancouver were dispatched to try to divert water flow from houses and clear culverts.

“We don’t see that amount of rain in that short amount of period all that often,” said District of North Vancouver Deputy Fire Chief Wayne Kennedy. “It’s kind of a rare occurrence, obviously we get a lot of rain on the North Shore and in Vancouver, but that was one time that I don’t remember anything coming down that fast and really giving us such a run.”

The floodwater also submerged the entrance to Argyle Secondary in Lynn Valley, which was closed Tuesday as officials assessed the damage to the school.

School District #44 Supt. John Lewis announced the high school would reopen for classes on Wednesday.

The flooding caused problems at another school, Braemar Elementary, with crews working through the day to fix a giant sinkhole that opened up underneath a blacktop.

Rainfall virtually turned Lynn Valley’s Fromme Road into a river, with water rushing down from an overflowing Hastings Creek.

While city crews used heavy equipment to try to clear debris from storm drains and blocked culverts, neighbours also pitched in by trying to remove debris and redirect flowing water.

“I’m trying to get the kids to stay asleep and the house not to flood,” said Cindy, an area resident holding a shovel in one hand and a baby monitor in the other. “We have two sump pumps going, and [the floodwater] is right at the door.”

Crews were eventually able to clear out a culvert that caused the Creek to overflow.

Officials said nearly two-dozen homes were evacuated because of the flooding. Many residents were allowed back into their homes as the rain eased up, but as of Tuesday afternoon, several houses that sustained severe damage remained uninhabitable, some for weeks or even months, said Mike Cairns, Asst. Chief of operations for DNV.

Meanwhile in Deep Cove, so much water came rushing down Gallant Avenue early Tuesday that it created rapids.

Businesses including a preschool and dentist’s office suffered water damage and had to close for the day.

As of Tuesday morning, West Vancouver had received 86.6 millimetres of rain, according to Environment Canada, while North Vancouver received just over 80 millimetres.

Elsewhere in Metro Vancouver, Coquitlam was soaked with 77.4 millimetres of rain, followed by North Burnaby with 72 millimetres and Vancouver Harbour with 63.8 millimetres.