Weathering another storm

Main track at the Snoqualmie Depot

during peak rainfall. 

November in Western Washington is synonymous with severe winter storms.  High winds, heavy precipitation, and power outages occur nearly every November and this year was no exception.  Fortunately, no significant damage occurred, but it was a nail-bitter because this was the first major storm event since completion of the PSE power plant reconstruction, and combined with the 2005-era Army Corps of Engineers section 205 river widening project.

Snoqualmie River at Snoqualmie

approaching peak flow.  Sandy Cove

Park is completely flooded.

The first indications of a threat usually arrive in the form of a flood warning.  A stage three flood is fairly common in Snoqualmie with several occurrences per year, while the more severe stage four floods occur every few years.  The National Oceanic and Atmospheric Administration ("NOAA") predicts peak water flow using computer models based on data from prior storms.  There is some margin for error, but the model updates as the storm progresses. 

South Fork of the Snoqualmie River

at peak flow.  Under normal flow,

there is approximately 20 feet of

headway under Bridge 35.

Flooding is one of the greatest threats to both the City of Snoqualmie and the Northwest Railway Museum.  Since 1948 there have been more than two dozen Presidential disaster declarations, and track and/or bridge damage has occurred in every event.  Tracking historical river peaks, there has generally been track damage at or above 43,000 cubic feet per minute as measured at Snoqualmie.  November 17, 2015's flood was projected at more than 48,000 cubic feet per second.  Actual peak flow was almost 49,000 cubic feet per second, yet there was no track or bridge damage.

The Museum is fortunate the flood reduction measures have worked in favor of preserving track and bridges, yet concerns remain about the ever-increasing frequency and severity of high rainfall events.  And, as with all high water events, all the affected bridges were inspected for damage and were found safe and suitable for service. Though no damage occurred, significant resources were utilized monitoring conditions and preparing for potential impacts.  Hopefully, snow levels will drop and the threat of further high rainfall events will diminish!                          (In the interest of full disclosure, the flood reduction measures have been controversial below Snoqualmie Falls and many think that flood impacts have now in creased in Fall City, Carnation, Duvall, and all points in between.)

Flood recovery continues

It has been an interesting winter for the Northwest Railway Museum. Our first January flood (historically, most flooding occurs in November) has created a variety of challenges but also a few opportunities.

To recover quickly, a rail contractor is performing the track repairs. For the Museum, this means that the track being repaired will get new ballast and a surface, line and dress. While we all would have preferred to avoid flood damages, it is comforting to know that the track will be at least as good as it was prior to the flood event.

It is an interesting period of contrasts too. Consider these two photos taken just two months apart at Fir Street in downtown Snoqualmie. One shows track being rendered unusable and the other shows it being rendered useful.

Here at the Northwest Railway Museum we are grateful for the broad-based community support that is allowing timely repairs. Without public support, the museum would not have been able to begin the flood repairs. An event such as this reminds some of us that many arts and heritage organizations can be just one major disaster away from permanent closure.

Major flooding hits Snoqualmie and the Museum

A major flood is occuring in Snoqualmie. Today is 7 Jan 09 and there are near-record water flows on the Snoqualmie River that have put nearly 2 miles of track and two timber trestles under water. Unfortunately, Google's Blogspot - a free service that hosts this site - is having technical problems today and it is not possible to post photos. However we have posted some more information and several photos on the main web site here.

We will try to post updates on the web site to the extent practicable but power is now out in Snoqualmie and this is being posted using an emergency generator.

The Museum including the Snoqualmie Depot and the Conservation and Restoration Center will be closed until at least Friday afternoon.

Threats to the Museum's collection

Last week was trying. Near-record rains again raised awareness about how vulnerable any museum collection is to the natural environment. Earthquakes, ash from volcanic eruptions, and flooding are the top threats facing the Northwest Railway Museum collection. And this week forecasters were calling for the "perfect storm" as a duo of tropical storms appeared to sequentially target the Snoqualmie Valley. As late as noon on Wednesday, November 12 everyone was expecting more than 10 inches of rain in a 24-hour period and USGS flow forecasts were calling for a river crest of 63,000 cubic feet per second (CFS). Never before had such flows been forecast and Museum staff began to wonder if water would actually get into the buildings for the first time ever. (The Snoqualmie Depot was built in 1890 and there is no record of water ever getting into the structure.) Thankfully, the storms ended up tracking differently and river flow peaked at about 45,000 CFS, but still over ten times the normal November flow.

For the Museum, the result was no damage. However when the threat was first forecast, Museum management made an immediate decision to close the museum and focus on mitigation: ensure nothing was sitting directly on the floor in either the Snoqualmie Depot or the Conservation and Restoration Center, and that anything vulnerable such as books and papers were at least six inches above the floor. Everyone is happy that record flooding never materialized but it is apparent that area storms are increasing in severity above storms of the last century. Planning for the future will require an assumption that storm related impacts will be greater, but by how much? The same question is on the minds of many museum managers across the region.

Included images: Snoqualmie Falls at 45,000 cfs with Museum's railway visible on the far river bank; South Fork at 6,000 cfs flowing below Museum's bridge 35.