With heavy rainfall in the forecast, Wednesday night's flood control open house at Myrtle Philip Community School — focusing on homeowners in the Tapley's Farm area of Whistler Cay — was well timed.
At the open house, the Resort Municipality of Whistler (RMOW) presented three different flood mitigation options for the neighbourhood, as well as one for Crabapple Creek, which jumped its banks during a heavy rainfall event in December 2014 causing extensive damage to at least two homes.
Option A would see a flood channel and detention pond built to the northwest of the railway tracks. The channel would have a top width of 11 metres and a channel depth of three metres. Two 1.5-metre culverts would be installed in the Valley Trail to drain the pond into the surrounding wetland area.
A weir would be installed at the entrance of the flood channel, and the RMOW could control the flow through the channel if need be.
This method would cost about $160,000 and have no direct impact on private properties.
"It doesn't prevent the water from Crabapple Creek and all the creeks from converging there, but 21 Mile Creek is the biggest piece of the flood issues, generally," said James Hallisey, the RMOW's manager of environmental projects at the meeting.
Option B is to construct a flood berm, or dyke, along the River of Golden Dreams from the Valley Trail bridge to the CN rail bridge.
The berm would be about 1.8 metres above the ground and have a top width of about four metres.
The total width of the completed berm would be about 11 metres, but the total area disturbed by construction would be about 15 metres.
The RMOW believes Option B would provide the best flood protection, but at a cost of $600,000 it carries the biggest price tag.
"It's also the most invasive option," Hallisey said. "I think by the time we would be done there really wouldn't be any trees between the backs of people's properties and the creek along that section."
Hearing that news, one open house attendee said simply: "that's a problem."
Option C involves re-grading or raising of flood-prone properties, either by the RMOW or homeowners themselves.
A professional flood-control engineer would ensure that flood and erosion risk wouldn't be transferred elsewhere.
Option C is expected to cost about $80,000.
The option presented for Crabapple Creek is to raise the Valley Trail by about 1.2 metres for a stretch of about 80 metres to prevent overland flooding.
All of the options presented at the Open House are preliminary designs — the RMOW is hoping to hear from the community before moving forward.
"What I'm hearing repeatedly is that people think that we should look at this on a bit of a bigger scope, and I'll take that back to council," Hallisey said.
Comments on the flood control options can be submitted to firstname.lastname@example.org before Monday, Oct. 5.