Stormwater project and streetlight replacements may cause traffic back-ups

Madison Parkers may experience a traffic set back or two this summer while traveling to and from the Park. Two unrelated City utility projects have the potential to slow progress on both Madison Street and Lake Washington Boulevard, though neither is expected to result in major congestion.

The biggest operation by far is Phase II of the Madison Valley Stormwater Project, which will be getting underway in July. As previously reported here, a pipeline will be constructed to collect stormwater from the northwest section of Madison Valley and channel it to a newly built mostly-below-ground tank located near the ball field in Washington Park. Bryan Nicholson, the project engineer for Phase II at Seattle Public Utilities, tells me that the project will begin next month with some excavation work related to the replacement of a major water main along Madison Street. No water outages are anticipated for Madison Park residents.

By late July we may see some traffic impact resulting from site work on the Washington Park end of the project. An access road will be created off of the north side of Madison Street, with the road’s entrance situated about halfway between the Madison Lofts Condos (2914 E. Madison) and Lake Washington Boulevard. On the site map above, which shows the landscape plan for the completed project, the “pedestrian entry” is also the location of the construction access road.

The pipeline itself will be an underground affair, with the impact of above-ground construction expected to be fairly limited—unless you happen to live in Madison Valley near the site of the staging area (shown in blue on the map below) or near one of the eight pipeline shafts. Construction of the pipeline will begin at the Washington Park end (shaft 8) in August.

There will be a lot of “spoil” removed from the pipeline route, which will have to be trucked out of the area. Originally, Lake Washington Boulevard through the Arboretum was designated as a possible truck route. According to Nicholson, it is much more likely that the trucks will exit the Valley by heading up Madison (travelling west) and approach the freeways by going north on 23rd Avenue. For one thing, it would be difficult for the double-long dump trucks to navigate the Arboretum, which is already over-burdened with traffic. A final route has yet to be approved by the City.

Phase II has an 18-month construction schedule, culminating in the fall of 2011. Nicholson reports that traffic along Madison Street should seldom need to be stopped during construction as there is enough width to allow two-way flow, even when construction is occurring along the side. For more information on the Madison Valley Stormwater Project, visit the City’s official site. Questions can be directed to a 24-hour hotline: (206) 455-5345.

The second City utility project with potential traffic impact is also long-term, but far more limited in scope. Over the course of the next year and a half crews will be replacing more than seventy Arboretum streetlights with new light-emitting diode (LED) lights. This project, which began last week, is focused on all of the streetlights along Lake Washington Boulevard, from the entrance at Madison Street on the south end to the entrance at Broadmoor at the north end. Unfortunately, the electrical cable for these lights is located underground and is deteriorating. For this reason, the cable will have to be replaced--in addition to the lights and the light poles--which means there will be boring and trenching operations. Because there is only a two lane road through the Arboretum, on occasion traffic will have to be stopped in one direction while work is underway. Flaggers will be in evidence during the project.

According to Seattle City Light spokesperson Mark VanOss, work will be scheduled to minimize disruption to rush-hour traffic on the Boulevard. This summer’s phase of the project will concentrate on 29 lights from the Broadmoor entrance at E. Foster Island Road to a point 500 feet south of the pedestrian bridge over Lake Washington Boulevard. These replacements should be completed by the end of October, with the work on the remaining 42 lights to begin sometime next year.

[Stormwater graphics courtesy of Seattle Public Utilities.]