'Critical areas' to get council review

As new scientific discoveries change what we thought we knew about the world, state law requires that new knowledge to be integrated into our land-management practices.

Beginning at this morning’s land use committee meeting, the city will begin doing just that by updating its “critical areas ordinance” to incorporate new knowledge, what is referred to as Best Available Science.

“We have to review our present ordinance to see if it meets that standard,” said city resource planner Steve Morse, who will spearhead the 15-month effort.

Consideration begins today on geologically hazardous areas, one of five sub-parts of the ordinance.

The other parts are wetlands, which probably will not be considered until after the first of the year; wildlife conservation areas, particularly streams and buffers; critical aquifer recharge areas; and frequently flooded areas.

The geohazard area, Morse said, is one that may require the most change.

“There has been a whole lot of new information, particularly in the last 10 years, about the degree of seismic activity on the south end of the island,” he said. “We have a much better fix on where the hazards are.”

The new data, some of which was uncovered just last month at a site on the IslandWood school property, indicates that the southern portion of the island – south of Eagle Harbor – has been the site of relatively recent and relatively intense earthquake activity, so much so that the city’s geological consultants have expressed some concern about any building in that area.

“Their recommendation, which we may not accept, is that the city obtain a hold-harmless agreement before allowing any building in that area,” said Morse, referring to a provision under which applicants would agree in advance to accept the risk of putting up homes or other structures there, and would not sue the city in case of property damage from a future calamity.

Morse said the city is also looking at ways to redefine the degree of slope that constitutes a hazard.

“Right now, we have two definitions in the code,” he said. “One defines slopes of greater than 15 percent as hazardous if they have soil types with building limitations, which is a very low threshold. The other defines it as 15 percent slopes with springs or impervious soil.

“It’s hard to tell which to use, but not all steep slopes are hazardous.”

South-end developer Kelly Samson agrees that the present definition is overbroad.

“People confuse a 15 percent slope with a 15 degree slope,” he said, “but there’s a big difference. A 15 percent slope means a rise of 15 feet per 100 feet of distance, which is not that much. Madison Avenue by the Pavilion is probably 8 or 9 percent.”

Unlike other critical areas – wetlands, for example – designation of a site as geologically hazardous would not automatically preclude building, Morse said.

“What that designation would trigger is the need for a more thorough site-specific analysis by experts of what has to be done to protect property,” he said. “Unlike some other critical areas, geohazards are managed for safety, not for ecological functions.”

While managing for safety doesn’t generally mean a prohibition on development, Morse said the required safety measures may make development plans economically unfeasible.

“If you spend enough money, you can solve almost any problem,” he said, “but sometimes, it’s excessively expensive.”

Existing structures on unstable slopes wouldn’t have to move, Morse said, but would likely have to undertake an investigation and possibly employ stabilization methods if the owner wanted to remodel.

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