35th Avenue SE Reconstruction

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Latest News
The 35th Avenue SE reconstruction project has reached the four-month mark and continues to progress. South of the bridge, pile driving is nearly complete, and rebar and concrete pouring are taking place. North of the bridge, more attention is needed to pile driving, which will be the focus in the next several weeks into at least mid-November.

The bridge work in the water is complete to align with the fish window. The creek bypass is no longer needed, and Penny Creek is flowing regularly.

Due to a combination of factors including pin pile methodology, obstructions found in the ground and a labor market shortage, the project is approximately a month behind schedule. At this time, the roadway is scheduled to be opened in early February 2019.


The construction sign has been placed at the project site Overview
35th Avenue SE is a three-lane minor arterial in Mill Creek that carries approximately 15,000 vehicles per day. The road was widened by Snohomish County in 2003 by using lightweight fill on top of a large peat deposit. The road has been continually settling since annexation by the City in 2005.

The rate of settlement has slowed, but portions of the road have settled over two inches in the past three years and two feet over the past 10 years.

Project location informationOne of the biggest areas of settlement is over the Penny Creek crossing between 144th Street SE and 141st Street SE, which also has the deepest deposit of peat material as a base. The water level in the surrounding wetlands has also increased due to several factors such as upstream development and downstream beaver activity. The rising water combined with a sinking roadway has resulted in several road closures over the past few years due to flooding.

Reconstruction Project
The reconstruction project will fix the road between 141st Street SE and 144th Street SE to eliminate flooding and associated road closures.

Work includes driving approximately 500 pin-piles through the peat into good bearing soil, constructing a concrete slab on top of the pilings, and then reconstructing and elevating the roadway on top of lightweight concrete fill. The project will raise the road elevation up to four feet above the existing roadway elevation.

In addition, the work includes treating stormwater from the roadway, which currently flows directly into the adjacent wetland without any treatment. Water quality and the method of distribution into the surrounding wetlands will be improved. Fish and wildlife will indirectly benefit from the improved water quality resulting from stormwater runoff treatment.

The width and alignment of the roadway will not change.

Timing
Reconstruction began on June 18, 2018 . The construction is slated to be substantially complete and open to the public in early February 2019.

Construction may occur between 7 a.m. and 9 p.m. Monday through Friday, or between 8 a.m. and 9 p.m. on weekends. Equipment is anticipated to run during normal working hours of 7 a.m. to 7 p.m. Monday through Friday for the majority of the project.

Detour Route
Traffic that normally utilizes 35th Avenue SE in Mill Creek will be detoured via 132nd Street SE and SR 527 (the Bothell-Everett Hwy). The City strongly discourages the use of side roads off 35th Avenue SE for unofficial detour routes, as these are residential neighborhoods not built for arterial traffic. The side roads should only be used by local access vehicles. Local access means you live in one of the neighborhoods adjacent to 35th Avenue SE, including Highland Trails, North Pointe, Silver Crest, Silver Glen and Webster's Pond.

Cost
The total cost is estimated at approximately $5,303,300. The State Department of Transportation office has included a $5.25 million funding package for this project by the City of Mill Creek. Snohomish County also provided a $50,000 small capital projects partnership grant.

Environmental Impacts
The project will require work over Penny Creek, where it crosses beneath the 35th Avenue SE roadway via two 54-inch culverts, and in the adjacent wetlands on the west side of the roadway and the east side of 35th Ave SE.

Raising the height of the roadway will require alteration of the existing stormwater discharge points into the adjacent wetland. The replacement storm drain lines will be placed a short distance into the wetland. A minimal amount wetland vegetation will be damaged or removed during excavation of the trenches to place the storm drain lines.

After the trenches have been backfilled and native soil placed where feasible, exposed soils and disturbed areas will be treated with native seed mix and willow stakes.

Groundwater encountered during construction will be discharged to an upland area or pumped into an above-ground tank and treated to meet state water quality standards.

There will be no discharge of waste materials to surface waters.

Frequently Asked Questions
Download and print a copy of the FAQs

Why are there no plans to widen the roadway to two lanes in each direction?
The roadway will not be expanded due to the associated environmental impacts to the surrounding wetlands and stream crossing. The peat bog surrounding 35th Avenue SE is a unique environmental asset, and is part of a large wetland and stream complex that provides wildlife habitat and flood mitigation. Thomas Lake is immediately to the east, and Penny Creek is a fish bearing stream that crosses underneath the roadway. Mosses in the peat can absorb and “lock up” excess carbon dioxide in the atmosphere, which can help mitigate global climate change since the acidic conditions in the bog results in slow organic decay.

Why is this project occurring in 2018 when other projects are happening?
The project timing is driven by two things: funding and functionality. The City is receiving a significant amount of funding from the state for this project. Some funds became available in 2017-2019, and all the funds must be used by 2019. Even though most of the work is occurring in 2018, it is possible some work might need to take place in 2019. By delaying a year, it could jeopardize the funds for project work running into 2020. Even if the City had waited until 2019, construction would still be occurring on the County’s 35th Avenue project and on the Swift Green Line project. In addition, by waiting, the City’s project costs would likely increase.

The functionality of the road also is an impetus for completing the project. Each year, the City currently is closing the road or diverting traffic into the center turn lane for extended periods of time due to water over the roadway. As part of the City’s commitment to preserving its infrastructure, timeliness is of the essence when scheduling this project.

Will this really fix the road? Will there be more flooding in the future?
The reconstructed roadway will be raised above the existing elevation. While flooding will no longer occur, since the roadway is a non-permeable surface, water may puddle during rain. However, following reconstruction, the roadway should not be closed due to impacts from water.

What kind of noise is expected?
The driving of 500 pin piles will be a noisy undertaking and is expected to last for 60 construction days. Pin piles are 6-inch-diameter “pipes” that are on average 60 feet long. They are pounded through the deep peat material into load-bearing soil. If you are at home during the daytime, plan ahead and take noise reduction precautions. Listen to the sound of the pin piles to understand sound impacts. https://www.youtube.com/watch?v=hxYI_YnUtH0 (sound starts about 2 minutes into this video).

Will the road be closed to traffic?
Yes, the road will be fully closed to traffic. Traffic will not be able to get by on 35th Avenue SE between 139th Street SE and 144th Street SE.

What is Mill Creek doing to mitigate traffic impacts in local neighborhoods?
The City is providing signage to inform people of the road closure at key points along the roadway outside and inside Mill Creek city limits. Electronic and static signage will be posted with detour routes. In addition, signage will be posted at the entrances to the Highland Trails, North Pointe, Silver Crest and Silver Glen neighborhoods that states “local access only” and “no outlet.” To help slow traffic down in the neighborhoods, temporary speed bumps will be installed. Digital speed feedback signs will be posted, and police will have presence throughout the neighborhoods and at stop signs to ensure drivers are behaving appropriately. In addition, the City is exploring the opportunity to partner with Waze to “block off” side roads in Mill Creek to deter people from being routed to them with the closure of 35th Avenue SE.

Why wasn’t there coordination about entities to ensure construction project timelines didn’t overlap?
The City coordinated with several other entities, including Washington Department of Transportation, Snohomish County, Community Transit, Puget Sound Energy, Snohomish County PUD, and the City of Everett. Because each entity has its own Capital Improvement Plan, projects will inevitably overlap at times. The City’s coordination effort with these other entities ensured that full road closures will not overlap and that one project’s detour route is not compromised by another project.

What are the implications of state funding for this project?
The state’s prioritization of funding for the 35th Avenue SE reconstruction project is a positive thing. In fact, state and federal funding is pouring into Snohomish County for many entities due to the tremendous growth in the area. This investment in growth management is positive for the area.

Historical Background Information
An MDNS was issued for the 35th Avenue SE reconstruction on September 23, 2015:

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