Top-10 lists make subjectivity king. I had no hard and fast rule on developing my personal top-10 list of stories I helped cover for ENR in the Pacific Northwest in 2010, so subjectivity reigns. Sure, there were other stories that could have made my list and others that maybe should have. But that remains the joy of creating your own list—you get to make it. I simply joined together events, some with lasting ramifications, others with engineering intrigue and others because they made people take notice. So, take a stroll down 2010’s memory lane with me and then think of what you would have put on your list.

Of course, what top-10 list is complete without a pair of honorable mention items? I couldn’t resist mentioning the new footbridge at the Capilano Park north of Vancouver. It is has engineering intrigue that will give visitors a cliffhanging view of the canyon below. In another item worth mentioning, work is always ongoing at the Hanford Nuclear Waste site. There, using new technology has become almost commonplace for the removal and disposal of hazardous materials. In 2010, crews planned for the use of new robotic machinery in a way they haven’t done before.

10. Let’s start with some mistakes that made people take note. A new highway near the Oregon Coast had bents moving out of plumb, causing engineers to head back to the drawing board to figure out why. Contractors and school officials in Seattle had headaches—literally—when a brand-new school’s carpet adhesive and moisture reacted to give off an annoyingly powerful odor. Contractors and owners again squabbled in Seattle when a 25-story apartment complex was ruled unsafe and announced it would be demolished. But the most intriguing of the 2010 mistakes came in Tacoma when crews actually built a highway off ramp in the wrong place. Blamed on a change in plans not communicated properly, the fix was demolished and redone and called “unfortunate and embarrassing.”

9. With tunnels already on the minds of folks in Seattle, crews had to fill in voids leftover from a 2-mile tunneling job through Beacon Hill for a light rail line. With sinkholes forming in neighborhoods, emergency filling took place in the first quarter of 2010.           

8. For the first time, Victoria, B.C., plans a secondary treatment of wastewater before sending it into the waters between Vancouver Island and the United States. Not only will a new wastewater treatment plant be good news for the neighboring residents, but also the construction of the facility will be a milestone for Victoria.

7. As you will soon see, pontoons played as a major theme in Washington. A pontoon-testing project gave engineers ample research to share with the world on the best practices in terms of building pontoons for floating bridges. As the owner of the most floating bridges in the world, Washington knew that finding out how to keep the pontoons working well in the long term was definitely in their best interest. Plenty of in-depth engineering helped create desired results.

6. Nature wreaked havoc across the world, but one nature-takes-charge story had a happy ending in Oregon. While work on demolition of an outdated dam near Medford took place, the river blew through a sand spit, changed course and then ran freely through a demolished portion of the dam. The river ran free for the first time in more than a century. The sudden change left some equipment stranded for a time, but nobody was hurt and the river’s eventual course fell in line with engineered plans.

5. In what appears to be a first for North America, Vancouver, B.C., had a temporary 27,500-seat stadium built to house two professional sports franchises while it works on a new roof for BC Place. The new Empire Field used 15,000 reusable parts shipped from Switzerland in 70 containers for construction and will now play host to football and soccer well into 2011. Once BC Place is complete, Empire Fields will be deconstructed and the parts shipped around the world for reuse in other similar stadiums.

4. One of the world’s longest floating bridges enjoyed a rebuild. The 1.5-mile crossing that connects the Olympic and Kitsap peninsulas in Washington underwent a total overhaul and portions of entirely new bridge. Functional testing was credited for catching glitches in the hydraulic system (designed to retract pontoons to allow ship passage), which saved engineers and owners massive problems down the road.

3. The Vancouver Olympics in February capped years of infrastructure replacement. From highways to new facilities, an Olympics always brings with it a wealth of construction projects. While not showy or flashy, the Vancouver games provided solid new facilities that remain in use nearly a year later and showcased sustainability Vancouver-style. Plus, a new light rail line and road improvements will serve all residents of Vancouver. This could easily have been the top story, but with most of the work done before 2010, it slipped to third on the list.

2. Ongoing and contentious helps describe the $4.65-billion 12.8-mile State Route 520 corridor improvement project in Seattle, which also includes the world’s largest floating pontoon bridge. Planning work continued in some areas of the project and bids were finalized in others, turning this east-west connector into reality, at least partially. Construction on this project, which is broken up into sections for bidding and funding, will continue for years and may remain a perennial top-10 story.

1. To tunnel or not to tunnel? While little actual construction work has happened on the replacement of Seattle’s Alaskan Way Viaduct, the planned nearly $2 billion bored tunnel is going forward, with a bid awarded in December. If you think the 520 project is ripe with contention, you haven’t read up on the viaduct process. This will be a world-class tunnel, which also means that one like it hasn’t been tried before. The ongoing arguing, bickering and uncertainty surrounding this project kept it in the headlines throughout 2010. Don’t expect 2011 to be any different.