Today I’m attending a meeting of the 520 Legislative Workgroup, trying to work out an agreed upon design for west end of the 520 bridge and a financing plan. You can look at the official documents at the website the state maintains for the project. I’ll provide some links to interesting ones in the middle of the post, but the basic website is www.wsdot.wa.gov/partners/sr520legislativeworkgroup/.
We heard community presentations from groups representing the proponents of each of the three alternatives we’re looking at for the Westside design. These were largely focused on specific details of the proposals and were somewhat dense. I have difficulty figuring out the politics of who each of these groups represent; it seems very complex.
Option A is a fairly straightforward expansion of the current bridge profile to 6 lanes, with similar entrances and exits. There is an additional drawbridge over the cut on Montlake, which improves north-south capacity. The main Westside exit remains at Montlake. Watch video: YouTube
Option K replaces the Montlake exit with a tunnel from Foster island to the South parking lot of Husky Stadium. The tunnel is wildly expensive and has huge environmental impacts. It also blocks us from adding additional transit capacity in the future, one of our original criteria for the project. Watch video: YouTube
Option L is similar to K but replaces the tunnel with a drawbridge. Watch video: YouTube
This was followed by presentations from the various permitting groups: Federal Highway Administration, US Environmental Protection Agency (EPA), US Army Corps of Engineers, WA Dept. of Ecology, National Marine Fisheries Service, WA Dept. of Fish and Wildlife, and the Department of Archaeology and Historic Preservation.
My conclusion from listening to these is that Option K is the most environmentally damaging option, and for a variety of reasons is unlikely to be permitted by the Army Corps of Engineers or the EPA because it provides the same function as the other options and is much more environmentally damaging. Federal Law seems to block them from permitting it.
Option K was described as having 18 times the impact on wetlands, and 5 times the amount of fill, and 5 times the amount of piling of the other options.
Some of the design elements of the various alternatives have impacts on the treaty tribes. In particular, they care (a lot) about the unimpeded flow of salmon through the Montlake cut and about any serious disturbance of Foster Island which was a burial ground historically.
Then we got into financing.
First we heard from the expert review panel about the various options. Their overall conclusion was that DOT did a reasonable job costing out the alternatives. They had some quibbles, but they thought it was reasonable.
They identified some serious risks in the various designs.
The “boat section” is the ramp from the bridge into the tunnel under option K. There are several acres of bridge that are underwater. This is incredibly hard to permit and is expensive to build.
The preferred method for digging the tunnel in option K (sequential excavation method) requires freezing the mud as you dig the tunnel. It would be the first time in the world that this method was used for a tunnel with both vertical and horizontal curves. Again, doing something for the first time is more risky.
The drawbridge in option L would be the longest such bridge in the world at this time. This might result in some problems. J
After their analysis we heard from DOT about the overall cost models for the bridge. I’ll write more about this later.
My interest is in getting a bridge design and funding plan agreed to this year. If we postpone the decision it will delay the construction of the bridge. My criteria:
Cost: It should cost less than $4.65 billion as we stated in the enabling legislation. Adding more cost raises the tolls significantly and uses money that we could use on other transportation projects in the region.
Permits: We must be able to get permits from federal agencies for the construction.
Function: We’re building a bridge, and we need to have both automobile and transit functionality.
Expansion: We should not preclude future generations from adding additional high-capacity transit to the bridge. This could be light rail, bus rapid transit, or something we do not yet envision. Our agreement is that the design will not preclude this in the future.
This will be fascinating to follow.