For many Squamish households, the Sea-to-Sky is more than a scenic drive — it is the daily link to work, school, appointments, and community activities. That is why this week’s storm system matters locally. Heavy rain and fast-changing conditions are once again putting a spotlight on how our community plans for safety, how agencies coordinate, and what each of us can do to reduce risk on Highway 99 and neighbourhood roads.
Regional authorities confirm that an atmospheric river is bringing significant rainfall to the corridor, and communities up the valley are already on alert. The Squamish-Lillooet Regional District (SLRD) reports that its Emergency Operations Centre is active and monitoring conditions closely. As a precaution, the SLRD has issued an evacuation alert for one property in the Pemberton Valley. Officials emphasize that no evacuation orders are in place at this time, and details about the alert are posted on the SLRD Emergency Alerts and Orders webpage. The District is working with Lil’wat Nation, the Village of Pemberton, and the Pemberton Valley Dyking District to track water levels and prepare for potential impacts.
Environment and Climate Change Canada has a rainfall warning in effect for much of the region, including areas from Howe Sound through the Pemberton Valley. Forecasters call for up to 70 millimetres of rain between Sunday, December 14, and Monday, December 15, with the heaviest precipitation expected overnight. Freezing levels are forecast to rise to around 2,500 metres by midday Monday, a change that can speed runoff at mid-elevations and put added pressure on creeks and drainage systems.
Those conditions are reflected in current river advisories. The BC River Forecast Centre has moved the Lillooet River and tributaries in the Pemberton area into Flood Watch status, meaning rivers are rising and could approach or exceed bankfull, with possible flooding adjacent to waterways. A High Streamflow Advisory remains in place for the South Coast, including Howe Sound and the Sea-to-Sky corridor. That advisory indicates rapidly rising water and faster-than-normal flows; while major flooding is not expected under that alert, banks can be unstable and conditions can change quickly as rainfall peaks.
On the road network, DriveBC has issued a travel advisory for Highway 99 in both directions between Main Street and Seton Lake Road — roughly 90 kilometres from just north of Pemberton to Lillooet. With heavy rain, the risks include debris flows, washouts, and short-notice closures. Drivers are being asked to avoid flooded roadways and allow extra time if travel is essential.
For Squamish residents, the immediate question is what these alerts mean here at home. Even when the heaviest rain falls north of town, our local streets, parking areas, and trailhead access roads can see pooling water, slippery surfaces, and reduced visibility. Officials note that slides are more likely in steep terrain, recently disturbed slopes, and areas with limited vegetation. That is relevant across the corridor, including well-used backroads and pullouts where people often recreate between storms.
The conversation about safety is not only about weather; it is also about habits. In past heavy-rain events, the RCMP and provincial agencies have reminded drivers to slow down, increase following distance, and avoid driving through standing water. Those practices remain best-practice guidance in any rainstorm. We have requested a local update from the Squamish RCMP on enforcement and education efforts during this system; we will share their advice once it is available.
At the infrastructure level, residents often ask what can be done to reduce hazards when the weather turns. The Ministry of Transportation and Infrastructure and DriveBC monitor corridor conditions and issue advisories and road-closure information as needed. After significant storms, agencies typically assess shoulders, culverts, and ditches to keep water moving and reduce the risk of surface flooding. Where persistent trouble spots are identified, a review of signage and drainage can follow. If the Ministry announces any specific safety improvements tied to this week’s system, we will provide those details as they are confirmed.
Preparedness at home also makes a difference. The SLRD is encouraging people across the region to update emergency plans, restock household kits, and ensure grab-and-go bags are ready for all family members, including pets. For many Squamish families, that can be as simple as checking that flashlights, batteries, basic first aid supplies, medications, warm layers, and non-perishable food are available for short disruptions. If travel is unavoidable, a vehicle kit and a full tank can provide added flexibility should traffic slow due to weather or if detours are required.
Neighbour-to-neighbour support is another practical step. Checking in on older residents or new families who may be less familiar with our winter weather goes a long way. If it is safe to do so, keeping an eye on street catch basins near your home can help reduce localized flooding. Where blockages or safety concerns are beyond what a resident can address, contact the District or the appropriate agency rather than attempting to manage a risky situation.
The broader takeaway is that atmospheric rivers are a recurring feature of life on the South Coast, and our shared safety depends on both daily choices and strong coordination between agencies. This week’s alerts are a reminder that multiple tools — accurate weather forecasts, clear advisories, and consistent driving behaviour — work together. The same approach applies after the rain passes. Community feedback helps identify specific locations where signage, lane markings, or drainage may need another look, and agencies can use that information when planning maintenance or improvements.
For now, the key facts are straightforward. A rainfall warning from Environment and Climate Change Canada remains in effect for the region. The River Forecast Centre has issued a Flood Watch for the Lillooet River system and a High Streamflow Advisory for the South Coast, including Howe Sound and the Sea-to-Sky. The SLRD’s Emergency Operations Centre is active, with an evacuation alert in place for one property in the Pemberton Valley. DriveBC has a travel advisory for Highway 99 between Pemberton and Lillooet, with a reminder that debris flows, washouts, and closures are possible. Across the corridor, motorists are being asked to avoid flooded roadways and plan for delays if they must travel.
As conditions evolve, residents can expect updates from the SLRD through its website and social media channels. DriveBC will continue to post highway advisories and any changes to traffic status. Environment and Climate Change Canada and the River Forecast Centre will provide revised forecasts and advisories as new data comes in. We have also asked local RCMP and the Ministry of Transportation and Infrastructure about any additional safety messaging or reviews tied to this system; we will share their responses as soon as they are confirmed. In the meantime, the most effective steps remain simple: stay informed, slow down, and look out for one another until the storm passes.
