Chapter 2 Description of Preferred Alternative 2.1 Introduction This chapter of the programmatic Sammamish Town Center Sub-area Plan Final EIS provides a more detailed description of the Preferred Alternative as adopted by the City Council and further developed in the Draft Town Center Plan. This chapter outlines, in specific terms the land use assumptions and proposed actions that are the subject of this evaluation. Refer to the Draft Town Center Plan for complete Plan details. The Preferred Alternative as adopted by Resolution No. R2007-271 includes a generalized conceptual land use map of the Town Center area (Figure 2-1) along with ranges of housing units, commercial (retail and office) space, and a list of possible civic facilities. Based on the generalized land use map and use parameters, a more detailed conceptual land use scenario (including transportation infrastructure and conceptual open spaces) was developed for the purposes of analysis in this Final EIS (Figure 2-2). In order to capture a conservative range of potential environmental impacts, the more detailed concept was developed using the upper limits of the parameters established by the City Council. Figure 2-2 illustrates a reasonable development scenario for the Town Center that allows for a programmatic evaluation of impacts. It is not meant as a final land use plan. Ultimately, the land use pattern in the Town Center will be determined by future City investments, council actions, and private development decisions. 2.1.1 Land Use Pattern Under the Preferred Alternative, as adopted by the City Council, the Town Center would include a variety of civic and community elements (recreational, cultural and educational activities), retail and office opportunities, and residential choices (3-6 story mixed-use and multi-family, town houses, cottages, and low-intensity single family). Development under the Preferred Alternative (directed by implementing regulations) would be required to maintain and, where possible, improve environmental functions and values of the area s natural resources (through habitat protection and enhancement, comprehensive stormwater management, and low impact development techniques). October 2007 page 2-1 City of Sammamish Town Center Sub-Area Plan FEIS
FILE NAME: Fig02-1_conceptual.ai CREATED BY: JAB / DATE LAST UPDATED: 08/22/07 N 0 200 400 800 Scale in Feet Figure 2-1 Town Center Preferred Alternative Planning Concept
Neighborhood Scale Mixed Use Area (NMU) NE Quadrant SE 4th St Core Mixed Use Area (CMU) Neighborhood Scale Mixed Use Area (NMU) SE Quadrant 228th Avenue SE FILE NAME: Fig02-2_prefalt.ai CREATED BY: JAB / DATE LAST UPDATED: 09/26/07 Neighborhood Scale Mixed Use Area (NMU) SW Quadrant 0 N 200 400 800 Scale in Feet Figure 2-2 Town Center Preferred Alternative Development Concept
Description of Preferred Alternatives As shown in Figure 2-2, the Preferred Alternative would create a core mixed-use area (CMU) on the west side of 228th Avenue SE, north of the Sammamish Commons, with development intensities gradually decreasing towards the Town Center boundary and surrounding neighborhoods. The Plan map follows a wedding cake approach with civic and mixed-use buildings concentrated around a centralized plaza or green space, low and medium intensity multi-family uses ringing the core area, and townhouses and cottages transitioning to nearby single-family neighborhoods. The Draft Town Center Plan also includes three neighborhood-scale mixed use areas (NMU); one north of City Hall in the SW quadrant and one in both the NE and SE quadrants (Figure 2-2). Residential units would be planned around these neighborhood core areas and transition outward following the same wedding cake approach described for the CMU. In total, the Preferred Alternative is estimated to add up to 164,000 square feet of civic amenities; 272,500 square feet of retail space; and 127,500 square feet of office space in the Town Center. The Preferred Alternative would include up to 2,000 new housing units spread throughout the Town Center area. New housing would be a mix of housing types that could include detached single-family homes, town houses, cottages, accessory dwelling units (ADUs), and mid-rise mixed-use and multi-family buildings (3 6 stories depending on location). A summary of potential land uses by quadrant is shown in Table 2-1. Land Uses Table 2-1 Draft Town Center Plan Development Assumptions NW NE SW SE Total Retail (sq. ft.) 115,000 20,000 117,500 20,000 272,500 Office (sq. ft.) 35,000 30,000 32,500 30,000 127,500 Total Commercial (sq. ft.) 150,000 50,000 150,000 50,000 400,000 Civic (sq. ft.) 0 0 164,000 0 164,000 Public Parking Public Parking (sq. ft.) 170,000 0 275,000 0 445,000 Parks and Open Space Public Parks (acres) 0.70 0.25 33 1.3 36 Housing (dwelling units) Low Intensity Single-family 67 0 11 0 78 Town houses, cottages, ADUs 22 90 40 166 318 Medium Intensity Mid-rise Multi-family and Mixed-use Multifamily 611 404 392 196 1,603 Total Housing Units 700 482 455 362 1,999 October 2007 page 2-4 City of Sammamish Town Center Sub-Area Plan FEIS
Description of Preferred Alternatives 2.1.2 Transportation and Parking 2.1.2.1 Circulation A range of new roads would be needed to serve new development and mitigate congestion. The Preferred Alternative would include both improvements to existing roads (including widening and grading) and creation of new roads. The road network proposed for the Preferred Alternative is similar to the alignment proposed under Draft EIS Alternative 1. Primary access from 228th Avenue SE to the CMU would be provided by SE 4th Street. A new road would intersect with SE 4th Street at approximately 222nd Place SE and form a loop connecting 228th Avenue SE at E Main Street. East Main Street would then continue east and turn south, connecting with SE 4th Street. A second new road would head southeast from SE 4th Street and travel to SE 8th Street. The Preferred Alternative would also include a system of non-motorized trails connecting all areas of the Town Center and connecting the Town Center to surrounding neighborhoods. Figure 2-3 shows the conceptual Town Center street layout including proposed roadway widths. Figure 2-4 shows the conceptual street cross-sections of the proposed roadways. While the exact location and configuration of Town Center roads may vary from the conceptual layouts and cross-sections presented in the Draft Plan, they were designed to fit with the topography of the area and provide appropriate connections to arterial and connector streets. The transportation implementation actions proposed for the Preferred Alternative are listed below: 1. Improve SE 4th Street by increasing the right-of-way and substantially grading the slopes between 228th Avenue and the core area to enhance access, visibility, and safety. 2. Convert Eastside Catholic s access road from 228th Avenue to a public street (extension of SE 4th Street). This action would require acquisition of a 72 foot right-of-way, lane configuration changes, a bicycle lane, planting strips, and sidewalk improvements. 3. Develop connector roads serving the northeast, southeast, and southwest quadrants of the Town Center. These roads would likely be built in phases coinciding with development activity in the Town Center. 4. Extend 232nd Avenue SE. This connection would provide access to other development sites just to the east of the Town Center and provide more circulation options. 5. Develop local access roads. The addition of public and private streets would be necessary to facilitate the planned Town Center development. 2.1.2.2 Parking Under the Preferred Alternative, parking would be accommodated by a combination of off- and on-street parking spaces and lots. Mixed-use developments in the CMU and NMUs would provide shared parking facilities. Such facilities may be shared between public and private uses and between different private uses. Most of the required off-street parking would be underground or within structures. See Figure 2-2 for conceptual parking structure locations in the CMU. City of Sammamish Town Center Sub-Area Plan FEIS October 2007 page 2-5
FILE NAME: Fig02-3_street-layout.ai CREATED BY: JAB / DATE LAST UPDATED: 08/22/07 Figure 2-3 Town Center Conceptual Roadway Network
FILE NAME: Fig02-4_street-cross.ai CREATED BY: JAB / DATE LAST UPDATED: 08/22/07 Figure 2-4 Conceptual Street Cross Sections
Description of Preferred Alternatives 2.1.3 Parks, Trails and Open Space The Preferred Alternative proposes a system of park, trail and open spaces throughout the Town Center with the intent of providing multiple benefits including recreation opportunities, ecological enhancement, and aesthetic improvements. As planned, the Town Center s open spaces would include, approximately 30-40 acres of public parks, 1.7 acres of privately developed public open space, five miles of trails, and approximately 60 acres of streams, wetlands, buffers, or other undeveloped forested area. The elements of the park, trail, and open space system are described briefly below and shown in Figure 2-5. Refer to the Draft Town Center Plan for complete details. The proposed system elements include the following: 1. Sammamish Commons. The Plan recommends possible enhancements to the complex that could include additional storm water treatment facilities, enhancements to the City Hall plaza with active edges such as heavily frequented retail shops or cafes, or creation of terraces that enhance the visual and pedestrian connection between the plaza and the panoramic views to the west. 2. Green Spine Northern Extension of the Commons. The Preferred Alternative recommends creation of a linear open space or spine about 60 feet to 120 feet wide extending north of the Commons for at least two blocks north of SE 4th Street. The purpose of this feature would be to provide an organizing structure for new development, add a visual and recreational amenity, and treat storm water runoff. The green spine could also serve as a public gathering space or setting for fairs, markets, and celebrations. 3. Plazas and Open Spaces in the Northeast and Southeast Sectors. The preferred Alternative includes smaller plazas, greens, or squares to serve the NMUs in the NE and SE quadrants (see Figure 2-5). These would be privately developed and maintained as part of the mixed-use centers and could range from one-third to one acre in size. 4. Residential Courts, Greens, and Gardens. Under the Preferred Alternative, the multifamily and townhouse developments in the Town Center would include common open space (directed by Town Center design guidelines). These open spaces may be a combination of active recreation, passive recreation, and natural areas and would ideally provide storm water management and other ecological functions. 5. Trails and Pedestrian Walkways. A network of pedestrian and bicycle trails are proposed throughout the Town Center. The conceptual trail network is shown in Figure 2-5. 6. Natural Areas. The Town Center site includes large vegetated corridors along streams and wetlands. Like all of the Draft EIS action alternatives, the Preferred Alternative directs development away from these areas. The Preferred Alternative also considers purchase of at least some of these areas for trail construction, storm water management facilities, and environmental enhancement. Details of such acquisitions would be developed at a later stage of the planning process. October 2007 page 2-8 City of Sammamish Town Center Sub-Area Plan FEIS
SE 4th St Green Spine City Hall FILE NAME: Fig02-5_parks.ai CREATED BY: JAB / DATE LAST UPDATED: 09/26/07 228th Avenue SE Protected wetland critical area N 0 200 400 800 Scale in Feet Figure 2-5 Town Center Parks, Open Space and Trails Conceptual Map