The King County Road Services Division is advising residents and motorists that a section of Novelty Hill Road between 243^rd Avenue Northeast and West Snoqualmie Valley Road will close for a four-week period beginning Monday, July 12 to allow for the construction of safety improvements. The county is requiring the Quadrant Corporation, developer of the Redmond Ridge and Trilogy communities, to construct the project, which will provide added safety for motorists while helping to stabilize the slide-prone hillside.

During the construction period, the project developer will construct a five to eight-foot shoulder along the north side of the busy, winding roadway. Given this stretch of Novelty Hill Road is considered a high-accident corridor, the addition of a one-half mile road shoulder will provide more maneuverability while enhancing sight distance and visibility.

The county is also requiring the developer to install a drainage system to help stabilize Novelty Hill Road and prevent local road flooding during the fall and winter months. The work responds to a 2003 geotechnical review that confirmed the potential for a major slide capable of severely damaging the roadway, which is an important east-west arterial serving the developments and other communities in the lower Snoqualmie Valley. The hillside is particularly vulnerable to sliding, given the presence of underground springs running through the various soil layers and the potential for saturation during prolonged heavy rain.

Construction of the road shoulder and drainage system will involve the installation of rockery at the west end of the project near 243^rd Avenue Northeast. In addition to creating safety benefits for motorists, the shoulder will accommodate a drainage pipe that will draw water away from a ditch along the upper side of the roadway. The water will then be diverted through a catch basin and into a bypass pipe carrying flow from Unnamed Creek, which is located west of the intersection of Novelty Hill Road and West Snoqualmie Valley Road. Pipes will then carry both the hillside runoff and creek bypass flow to the bottom of the hill and into the Snoqualmie River, which will help reduce saturation of the roadbed and hillside.

In an effort to fulfill the county’s requirement to minimize traffic impacts, the developer will work extended hours and weekends to complete the project as quickly as possible during the driest period of the year, a necessity given the type of work that will be performed. Due to the steep and winding configuration of Novelty Hill Road, it was determined that work could not safely be performed if the road had remained open to one lane of traffic. Night work was also ruled out because it would not be possible to provide enough light for the length of the work zone to ensure the safety of construction workers.

Uniformed officers will be used as necessary, and traffic engineers will work to synchronize traffic signals at certain locations to improve traffic flow. King County will also defer small-scale maintenance projects it had planned to construct in the lower Snoqualmie Valley until after the completion of this project to further minimize disruptions. Motorists are additionally encouraged to visit the county’s My Commute Website to view selected traffic cameras in the Snoqualmie Valley to plan their commute.

During the construction period, motorists should use State Route 203 and Woodinville-Duvall Road as a detour route. Alternate routes include Trilogy Parkway, Northeast 133^rd Street, Redmond Ridge Drive and Union Hill Road. Duvall-area businesses will remain open throughout the construction period.

The road closure will run from 5 a.m., Monday, July 12 through midnight, Friday, Aug. 6. As a follow-up, intermittent closures lasting up to 15 minutes may be necessary during non-peak travel periods through Sept. 1 to accommodate clean-up work.