Streets and Storm

Streets and Pedestrian

Traffic Impact Fee Program Implementation, City of Carnation

Roth Hill is currently assisting the City to put in place a traffic impact fee to assess development for its impacts on City transportation facilities. Our current task involves seeking out funding to set up the program and presenting the conceptual program to City leaders.

NE 24th Street Improvements, City of Medina

Roth Hill provided surveying, public involvement, design, permitting, and construction observation/administration services for this street and pedestrian improvement project. This street is one of the City’s main arterials and the main link to the Evergreen Point community north of SR 520. A 2,600-linear-foot section of street was improved to provide better pedestrian access and to provide traffic calming in response to the specific needs of the community. Several public meetings with both the neighbors and the City Council’s input assisted to define and finalize the overall project scope. A deteriorating curb and gutter and a 4-foot sidewalk along the north side was replaced with a 5-foot sidewalk separated from the curb and gutter by a 4-foot landscape strip. A sidewalk, curb and gutter were also added to the south side for half the length of the project. The overall pavement width including the shoulder was reduced, although two 11-foot lanes were maintained. The scope also included additional storm drain crossings and catch basins, reconstruction of the vertical alignment to improve drainage and to minimize grade change impacts at the back of the sidewalks and the full replacement of the City of Bellevue’s existing 6-inch AC watermain with 8-inch ductile iron pipe. A final asphalt concrete pavement surface and striping completed the work.

Overlake Drive West Phase 2 Improvements, City of Medina

Roth Hill provided surveying, public involvement, design, permitting, and construction observation/administration services for this project. This road runs along the southerly edge of this lakeshore community where children walk to the local elementary school and the nearby beach park. In order to provide a safe, attractive and low maintenance walking corridor on this 1,900-linear-foot section of 2-lane paved road with very narrow shoulders, a 5-foot sidewalk, curb and gutter was added to one side. This required a series of existing ditches and driveway culverts to be piped and covered. As a result, over 1,600 linear feet of 8- to 18-inch storm drain pipe and catch basins was installed. Other improvements included reconstructing the entire vertical alignment to improve drainage and to minimize grade change impacts, road subgrade reconstruction in several locations and a new asphalt concrete pavement surface and striping. Mailbox locations were grouped, where possible, with new custom-made wooden mailbox stands. Several public meetings with both the neighbors and the City Council’s input defined the overall project scope.

Storm Drainage System Projects

Park Place North Storm Drain Project, City of Renton

Roth Hill is assisting the City with the design of a new storm drain system along a steep slope on the east shores of Lake Washington. The project consists of installing approximately 160 feet of 12-inch HDPE pipe down a steep slope. We are providing the City with topographic surveying and geotechnical services in addition to the design of the steep slope portion of the storm drain system. We are preparing a design report in which we recommend design details and construction procedures to account for flow, the pipe weight, overland construction, and thermal expansion of the pipe. The majority of the steep slope portion of the pipe will be installed above ground to allow for easier construction and less disturbance of the existing slope.

Peters Creek Culvert Replacement, City of Redmond

The City of Redmond identified the need to replace the existing twin corrugated metal pipe culverts at NE 87th Street with a fish-passable culvert as part of a comprehensive plan to improve Peters Creek, a tributary to the Sammamish River. Roth Hill was hired to provide topographic surveying, design, permitting, and easement preparation for the proposed culvert replacement project that will consist of a single concrete box culvert sized according to the required fish passable criteria per the Washington Department of Fish and Wildlife. Roth Hill teamed with a local stream biologist and geotechnical engineer to prepare design documents which will include stream enhancements.

NE 28th Street to 80th Avenue NE Storm Drainage Improvements, City of Medina

This project involved the replacement (upsizing) of 500 linear feet of existing 15-inch concrete storm drain pipe and the addition of 1,000 linear feet of 18- and 24-inch corrugated polyethylene pipe (CPEP) storm drain pipe to upgrade the drainage system to handle higher future flows at the downstream end of one of the City’s main drainage basins. A key element of the project involved the bypass of high flows around a natural drainage ravine through the Fairweather Nature Preserve. This ravine experienced severe erosion. Low flows, controlled by an outlet control structure, continue through the ravine to maintain the aesthetic nature of the preserve. A sediment control vault located at the downstream end of the ravine traps sediment before runoff enters the lake at the outfall. The project was constructed on City and WSDOT right-of-way and on Bellevue School District property. This involved the procurement of a Utility Franchise Permit, temporary easements, and permanent easements.

Medina Creek Restoration Study, City of Medina

Roth Hill, working with a team of consultants, studied the feasibility of restoring Medina Creek, a degraded urban channel, to a fish-friendly stream. The project focused on: drainage basin mapping; Flo-Tote™ stream flow monitoring in culverts, upstream and downstream of existing detention; rainfall records review; calibrating the Stormshed ™ model to flow monitoring data; and predicting stream velocities and water surfaces. Roth Hill performed a hydraulic analysis, using Stormshed™ to identify and recommend future stream improvements. Other team members addressed biological and landscaping issues. Design and construction are planned.

NE 12th Street, Evergreen Point Road Phase II, City of Medina

This project involved replacement (upsizing) of 2,300 linear feet of existing 8- to 15-inch concrete storm drain pipe with 8- to 24-inch CPEP storm drain pipe and replacement of existing catch basins with Type 2 catch basins. The project was especially challenging due to the presence of several existing utility crossings over and under the proposed alignment, and the need to maintain two-way traffic during non-working hours since the affected streets adjoined primarily residential property.

77th Avenue NE and Evergreen Point Road, City of Medina

This project involved the installation of approximately 1,000 linear feet of 4-inch perforated and 6-inch solid CPEP to pick up both subsurface and surface drainage from several existing residential properties. Several existing roof and yard drains were discharging through the existing curb and gutter into the street, which was causing the gutter to erode in addition to not conforming to current drainage standards. Also, the properties all slope down to the street, which meant that any subsurface water from irrigation systems and natural groundwater seeped over the curb creating a constant wet condition year-round. Several hundred feet of damaged curb and gutter were also replaced as part of the project.

2.0 MG Water Storage Reservoir Drainage/Detention Pond System, King County Water District No. 111

1,000 linear feet of 8- and 12-inch CPEP storm drain pipe, catch basins, and a storm detention pond were constructed to handle drainage for a site with two existing water storage tanks and a new 100-foot-diameter concrete reservoir. The drainage system included provisions for emergency overflow and drainage of the reservoir when needed. The detention pond was constructed prior to the excavation for the reservoir in order to serve in the interim as a sediment control pond. The completed pond divided into two cells, with a quarry spall barrier, functioned to settle out solids before entering the downstream drainage system. The design included the preparation of a drainage report for review and approval by King County.