Slope stability studied back in '78

ROCK SOLID RESEARCH - Geologist Denny Maynard, of Denny Maynard & Associates, did his Masters thesis on geomorphology in 1978 using the Seymour area as a study area.
By Jennifer Maloney (Rob Newell photo)

Like many North Shore residents, Denny Maynard hopes the District of North Vancouver won't wait for another disaster to happen before it gets involved in protecting the sensitive residential areas around the Seymour River Escarpment.

Unlike others, Maynard made his opinion known to the District in 1978 when he completed his Masters thesis on how to incorporate geomorphology into community planning.

"I was trying to show the impact factors that should be considered," Maynard said. "The intent was to show how you could take geological information as one part of the planning process."

Maynard chose to study the Seymour area because it was known to be fragile and at that time the development was just getting started. Although some development of Riverside Drive already existed, Mount Seymour Parkway was sparse and everything above it was forest, he said.

The District supported his study by providing him with maps and background information. In return, Maynard offered his findings to them, but they were never officially incorporated into their planning.

One of the impact factors mentioned in Maynard's thesis was slope stability. Although he didn't specifically address hazard assessments, he did indicate how areas prone to slope failure could be identified.

"In the Seymour area most zones of instability are indicated by numerous, but small failures," the report stated. "In many cases flow of saturated soil, indicating an excess of groundwater seepage, is the only evidence."

Maynard reported slides and washouts were common along Lynn Creek, McCartney Creek and the Seymour River.

He found the scarp itself to be unsuitable for development, but points out there has been relatively no development along it since.

"Unfortunately at that time there were houses already there," he said. "It's devastating for the people involved in that slide."

A year after his thesis a slide occurred that destroyed a house built at the bottom of the slope, which triggered geotechnical assessments on the area. In Maynard's opinion the District's next step should have been to have site specific tests done on the areas that required more follow up.

"You can't just turn a blind eye," he said. "The engineers who put out the report did their job, but it's recommendations got lost in the bureaucracy."

After last Wednesday's slide, friends of Maynard were evacuated from their home, which was built beside the house on Berkley Avenue that lost its backyard. He suspects site specific tests are now being performed on his friend's house and those in the immediate vicinity.

"It seems the District gets interested in these things every time they happen," he said. "They fix them and then life carries on until the next disaster."

At Monday's District council meeting, James Ridge, the District's chief administrator, announced a forensic review of the area was already underway. Priorities, he said, were monitoring the site and mitigating further hazards. He said a geotechnical engineer would be hired by the District for a minimum of two years to look at the area's drainage and provide a full analysis of the slope. The District also plans to implement a slope management plan and look at new property regulations.

"We will bring forth an action plan," Ridge said in front of a overflowing council chamber. "Our priorities are very different now than they were last week."

Maynard is impressed with how the District is dealing with the aftermath of last week's slide and is eager to finally see steps taken to ensure long term stability of the slopes. Regardless of whether the District of North Vancouver is legally required to do so doesn't matter, he said.

"There's a moral responsibility. Our professional association is bound by a code of ethics to make the public aware of health and safety issues."