KINGSTON LID STORMWATER RETROFIT

Transcription

1 KINGSTON LID STORMWATER RETROFIT LID RETROFIT IMPLEMENTATION PLAN Prepared for: Kitsap County Public Works Surface and Stormwater Management (SSWM) 614 Division Street (MS 26A) Port Orchard, WA December, 2012 Prepared by:

2

3 Table of Contents 1.0 Introduction Kingston Background Information Study Area Goals of Retrofit Study Methods Determine the Study Boundary Study the Existing Infrastructure within the Study Boundary Downtown Kingston Master Plan Miller Bay Road Corridor Project: Downtown Kingston Port of Kingston Master Plan Kitsap County s Low Impact Development (LID) Guidance Manual Identify Potential LID Best Management Practices (BMPs) Bioretention (raingardens) Pervious Pavement Skinny Streets Cisterns Amended Soil Evaluate Site Suitability in the Study Area through Field Investigation Compile Data Evaluate Potential Retrofits Approach for Preliminary Retrofit Designs Street Sections Parking Lot Retrofits Site Specific Retrofits Other Considerations Additional Site Evaluations Summary... 14

4 List of Figures Figure 1: Project Limits and Areas of Primary Interest (API)... 2 Figure 2: Preliminary Retrofit Locations Identified by Stakeholders Figure 3: Locations of Prioritized Retrofits Appendices Appendix A... Retrofit Project Sheets Appendix B... Preliminary Cost Estimates Appendix C... Site Assessment Field Notes Appendix D... Prioritization Matrices

5 1.0 Introduction Kitsap County is a unique area located between Puget Sound and Hood Canal. Over the years as more and more people have discovered this diverse area, growth in population, development, traffic, and industry have impacted the surrounding ecosystem. Kitsap County has prioritized stormwater management improvements as a critical path to restoring the County s valuable natural resources and habitat. 1.1 Kingston Background Information Located along the shores of Apple Tree Cove, Kingston was founded in 1853 by Benjamin Bannister as a lumber town. With passenger ferry service starting in the 1920 s, and vehicle ferry service as early as 1923, Kingston quickly became a sought after destination for Seattle residents among others. Today the Little City by the Sea has grown to a population of over 2000 full time residents. Kingston is one of the most urbanized town centers in Kitsap County with approximately 65% impervious surface area. A majority of the development is commercial and high density residential land use. The Kingston town center, along with a moderately developed shoreline, borders Puget Sound. Kingston also includes a major Washington State Ferry Terminal and associated traffic issues. The high average daily traffic (ADT) makes this a significant source of road runoff and stormwater pollution. The community values the natural resources and shoreline parks. Additionally, the business community has been responsive to the water quality and natural resource protection messages of the last few years, as demonstrated by their compliance with storm maintenance requests, and is receptive to changing management practices to reduce polluted runoff. Past Master Planning efforts for Kingston have worked to create a clear plan for future growth and revitalization, as well as identified needs for further study. This LID Stormwater Retrofit Study is intended to compliment past efforts with a focus on stormwater quality and quantity recommendations within the core of the Kingston area. 1.2 Study Area The area evaluated in this study is approximately 157 acres, as shown on Figure 1. The study area was broken into five areas of primary interest (API s) based on both location and land use. The five API s evaluated are listed below along with their main land use category: 1. Downtown Core Medium Density Mixed Use 2. Village Green Low Density Mixed Use 3. SR 104 Corridor Medium Density Commercial 4. Lindvog Road NE Low Density Commercial 5. East Side Medium Density Residential Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

6 Figure 1: Project Limits and Areas of Primary Interest (API) N Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

7 1.3 Goals of Retrofit Study This study is intended to compliment both the Kingston Downtown Master Plan, as well as the Kingston Commons planning and design processes which overlap this project timeline. This study is intended to identify, characterize, and prioritize Low Impact Development (LID) stormwater retrofit opportunities and needs on both public and private property. By developing concept level designs for the identified projects, this study will be used for property owner education and to pursue funding for future implementation of the identified projects. The results of this study may serve as guidelines for planning future projects, and to communicate project opportunities with the public and private commercial property owners. By including community stakeholders in the identification and prioritization process, those involved will have a better understanding of the local hydrology, and what can be done to improve the current conditions of the stormwater system that serves the Kingston area. This report is intended to serve as a guide for similar efforts in other areas of Kitsap County to aide in the process of studying, identifying, prioritizing, and designing stormwater retrofits. Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

8 2.0 Methods Following past efforts to develop the Downtown Kingston Master Plan, the LID Stormwater Retrofit Plan included engineering assessment, community and stakeholder involvement, and coordination between County departments, as well as coordination with other planning efforts such as the Miller Bay Road Corridor Project in order to identify, evaluate, and prioritize potential retrofits. Similar to other retrofit evaluations that have been undertaken throughout Western Washington, a step by step approach included: 1. Determine the Study Boundary a. Identify the geographic area, and determine boundaries based on topography, land use, and hydrology. 2. Study the existing stormwater infrastructure within the Study Boundary a. Identify areas without infrastructure improvements, or without adequate infrastructure through GIS mapping, aerial photography, as built drawings, and previous studies. 3. Identify potential LID best management practices (BMPs) 4. Evaluate site suitability in the Study Area through field investigation a. Identify areas of significant concern i. Erosion, flooding, critical areas ii. Extensive areas of impervious surfaces, or with high pollutant potential iii. Failing or inadequate infrastructure b. Identify areas of opportunity i. Drainage convergences ii. Areas planned for other infrastructure improvements (i.e. pavement replacement, water or sewer main replacement, bicycle lane or sidewalk improvements, etc.) iii. Public or private unplanned green space iv. Opportunities to restore vegetated buffers, habitat, soil, or other environmental constituents with dual purpose landscape features. c. Talk with community members i. Collect anecdotal data about historic hydrologic problems or concerns ii. Collect anecdotal data about the effects of changes in land use or topography iii. Review County complaints related to drainage, flooding, or erosion. 5. Compile data a. Create a list of potential locations for retrofits b. Match potential locations with potential BMPs c. Identify potential prioritization criteria including environmental, economic, and social components 6. Evaluate potential retrofits a. Involve community stakeholders and County staff to refine identified project locations, BMPs, and prioritization criteria b. Estimate potential costs Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

9 2.1 Determine the Study Boundary When evaluating a geographic area of study for stormwater management, the boundaries of the study area should be determined based on topography, land use, hydrology, environmental protection areas, and plans for future growth or development. 2.2 Study the Existing Infrastructure within the Study Boundary Review existing storm drain collection mapping to determine general stormwater flows, and identify areas of drainage convergence, areas with some of the oldest infrastructure, and areas that may have no formal drainage infrastructure at all. Review other studies and reports prepared for the area, and understand the objectives and findings in relation to stormwater. Proposed improvements in other studies may not appear to be directly stormwater related, but their location may lend well to improve stormwater management. For example, while bike lanes may be proposed for a variety of transportation or community planning reasons, their location alongside the vehicular lane of travel on the road and their relatively low traffic wear lends well to pervious pavement facilities. Sidewalk improvement projects are another convenient opportunity for stormwater management integration Downtown Kingston Master Plan The purpose of the Master Plan was to facilitate downtown revitalization, improving Kingston s overall quality of life through an improved built environment and economic development. Its scope intended to describe desired development, amend policies and development regulations, and facilitate financing mechanisms. County staff was directed to further analyze assumptions built into proposed policy amendments and incorporate a more holistic approach to streetscape improvements with respect to parking, stormwater management, and financing. It was discussed that Current stormwater management requirements stymies desired development due to lot configurations and expected development. The Master Plan identified the following LID Objectives: Streetscape Study, Community Stormwater Plan, Establishment of LID/CRID, and to pursue grant funding. The Downtown Master Plan provides the community s goals for the time frame extending to 2025 and is conceptual in nature. Information from this Master Plan was used to understand and learn from the economic development efforts and considerations, parking concerns, and overall community vision and priorities Miller Bay Road Corridor Project: Downtown Kingston The Miller Bay Road Corridor Project addresses the circulation component of the Downtown Master Plan in more detail, and establishes guidelines for a Complete Streets approach for the public rights of way in the downtown. This project also looks at the feasibility of specific circulation revisions in the downtown associated with traffic accessing the ferry including transit, bicycle and pedestrian access improvements. Information from this study was incorporated to envision what the future traffic (including vehicular, pedestrian, and bicycle) patterns may look like surrounding the ferry terminal and the intersection Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

10 where the current community center is located. This knowledge and understanding helped to identify areas for retrofit opportunities, as well as to plan for those areas that may soon be altered. The team working on this report is also working closely with the County Roads Department, and Washington State Department of Transportation in coordination for the traffic revisions planned for ferry traffic. With the knowledge of these future improvements, for the purposes of Kingston LID Stormwater Retrofit Plan it is assumed that Main Street will return to 2 way local traffic rather than the current 1 way ferry queue. It is also assumed that SR 104 will be modified to allow for all traffic loading and unloading from the ferry Port of Kingston Master Plan This study is a facilities plan, with documented goals and priorities to guide the future development of improved or new Port structures and other physical facilities. This plan identified the then current facilities of the Port along with facilities that would further enhance the value of the Port to the Community. The Port s Master Plan identified short, medium, and long term goals under the categories of park, marina, parking, and commercial development. Information from this study was used to understand the Port and community s priorities for parking improvements, future commercial development, marina improvements, etc Kitsap County s Low Impact Development (LID) Guidance Manual The purpose of the LID Guidance Manual is to make LID accessible for all designers, developers, and builders in Kitsap County. The LID goals are to protect water quality, preserve wetland and stream functions, encourage aquifer recharge where appropriate, and to provide cost effective stormwater management solutions. This Manual provides site assessment and planning guidance and procedures, guidance on integrated design, design and flow modeling guidance and standards for a variety of BMPs. Information from this manual was used for consistency between documents, as well as guidance for assessing the feasibility of potential sites for retrofits and design guidance for specific BMPs. 2.3 Identify Potential LID Best Management Practices (BMPs) Creating a menu of LID BMPs aids in determining which BMP may be most appropriate for a particular location or need. LID BMPs considered in this evaluation are summarized below Bioretention (raingardens): Bioretention cells can be use to detain, treat, and infiltrate stormwater from a variety of surfaces. Typically, a bioretention cell consists of a minimum of an 18 depth of compost amended soil over a drain rock reservoir for collection or infiltration of the treated stormwater. They are often planted with native, draught tolerant plants. Benefits of bioretention facilities include enhanced water quality treatment, flow attenuation, aesthetic and habitat benefits, and potentially groundwater recharge. Bioretention can take many forms: Raingarden Cell: A raingarden cell is a landscape depression, typically with planted natural side slopes fed by surface flow. Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

11 Raingarden Swale: Very similar to a raingarden cell, a raingarden swale is a longer, linear raingarden often located parallel to a roadway or other linear impervious surface. Due to the length and size of this type of facility, they often contain flow control weirs to allow for changes in grade. Raingarden Bulb out: Often existing stormwater flows are directed to street intersections. By taking advantage of existing infrastructure locations, and providing pedestrian improvements for street crossings, raingarden bulb outs are located at intersection corners to collect, and treat stormwater before it crosses the intersection. These bulb outs often fit in unused corners adjacent to angled street parking, or bookend parallel parking areas. Infiltration Flow through Planter: For more densely developed areas, space is at a premium. To maximize bioretention areas, infiltration flow through planters feature vertical sides. Due to available space this BMP may be sized to only treat the first flush of stormwater, and allow the larger storm flows to bypass the facility during a rain event. Street Tree Biofilters: For even more densely developed areas, biofilters offer an even smaller footprint for bioretention. Their compact treatment footprint and inconspicuous appearance as a stormwater facility lend well to fully built out rights of way. Biofilters can serve as treatment only facilities or in combination with an infiltration facility Pervious Pavement: Pervious pavements are similar to conventional concrete and asphalt pavements, but allow stormwater to flow downward through the pavement section. The pervious pavement section itself provides some filtration and sediment removal. It is typically underlain by a chipped rock reservoir for collection or infiltration of the stormwater as well as structural support. Common pervious pavements include: Porous Asphalt: A flexible pavement, often requiring a minimal pavement section thickness, with an expected lifecycle of approximately 20 years. Pervious Concrete: A rigid pavement offering significant durability, with an expected lifecycle of approximately 50 years. Permeable Pavers: An interlocking impermeable paver system with gaps between pavers that allow stormwater to flow through downward into the underlying subgrade. Grass or Gravel Pave Systems: Typically heavy duty plastic grid systems, both rigid and flexible, that can be filled with chipped gravel or soil with a grass seed mix. These systems are often used for fire lanes, overflow parking, or other areas with only occasional vehicular traffic use Skinny Streets: Skinny Streets are typical street sections minimizing the impervious surfaces needed for vehicular travel Cisterns: Rainwater harvesting typically uses cisterns for storing rainwater from roof areas. Cisterns can store rainwater for a variety of uses ranging from detention to reuse opportunities such as Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

12 irrigation, toilet flush, laundry, wash down, or even, potentially, potable uses. Cisterns can help to delay storm surges from entering the stormwater collection system by slowly releasing the collected water when an orifice device is installed on the cistern outlet Amended Soil: Compost amended soil helps to bring organic life and function back to heavily compacted or stripped soils. By tilling compost amended soil into the existing soils, it increases the stormwater holding capacity of the soil, provides a more nutrient rich and beneficial growing medium for plants, and thereby more closely mimics the hydrologic condition of the pre developed condition. 2.4 Evaluate Site Suitability in the Study Area through Field Investigation It is important to walk through the entire study area to observe existing drainage impacts and opportunities, and visually inspect existing drainage systems. Ideally, the study area should be evaluated during or immediately following a rain event, as well as during a dry period. During the site walkthroughs, note areas showing signs of erosion, sediment transport or accumulation, flooding, or failing or inadequate infrastructure. Also note expansive areas of impervious surfaces, and those with high pollutant potential. Areas where drainages converge should be documented and evaluated for potential retrofits. Landscape strips parallel to roadways, other linear impervious surfaces, and public or private green spaces that have not been specifically planned as recreation areas or critical areas should be evaluated as to how to maximize their potential. Note vegetated buffers or other natural areas that may need restoration. Often restoration activities can be opportunities for dual purposed improvements for stormwater management as well as habitat improvements, native vegetation enhancement. When walking through the study area, it is important to reach out to those most familiar with the historic drainage conditions. Community members often have the best anecdotal knowledge about what changes have occurred in the past to the surrounding hydrology, topography, land use, and infrastructure improvements even if they do not always know the cause of or reasons for those changes. It is also helpful to inquire about any past complaints or concerns submitted to the County by community members. Community stakeholders from the following sectors were included in the process of determining potential retrofit sites as well as overall drainage concerns: Kingston Citizen Advisory Council Port of Kingston Village Green Foundation Kitsap County, including representatives from Surface and Stormwater Management (SSWM) Division, Department of Community Development (DCD), Public Works, Roads, and County Council Members Community Members Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

13 While no formal complaints or concerns had been filed with the County in the Kingston area, several community members shared stories during public meetings and site reconnaissance walks of the study area. The vast majority of concerns were related to the area of lowest elevation across from the Village Green Park area where several drainage conveyances converge and discharge to the nearby shoreline. Some of the areas of concern identified during the community stakeholder meetings were addressed at the specific area identified (i.e. Thriftway Parking Lot, and Firehouse Theater), while others were addressed by proposed retrofits upstream of the specific area (i.e. low lying area south of Village Green) by recommending retrofits closer to the sources of high stormwater runoff volumes. Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

14 Figure 2: Preliminary Retrofit Locations Identified by Stakeholders N Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

15 2.5 Compile Data After all data has been collected from previous studies, site reconnaissance, anecdotal interviews, and available infrastructure data, potential retrofit sites should be listed and described based on specific need, opportunity, and/or constraint. Based on the described needs, opportunities, and/or constraints of each potential retrofit, BMPs should be evaluated to determine which may be most appropriate. Input from key community stakeholders is important in selecting specific BMPs. Potential retrofits can take different forms. A specific site with defined boundaries and a single BMP strategy is one option. Others may be more appropriate to be implemented as a development standard such as a typical street section incorporating several BMPs. Typical street sections can aid in a cohesive neighborhood look and feel, and can be implemented incrementally as development or redevelopment occurs. Based on engineering knowledge, community priorities, and criteria identified in related studies, a list of potential prioritization criteria should be developed. These criteria will be the basis for determining which potential retrofits should be prioritized for further pursuit. The prioritization criteria determined through this analysis process includes: Water Quality Treatment Benefits Flow Control Pedestrian Connectivity Public Safety Parking Public/Private Collaboration Aesthetics Increased Recreational Opportunity Reduced Maintenance Costs Educational Opportunity Community Plan Support 2.6 Evaluate Potential Retrofits Through a collaborative process with the community stakeholders, each identified retrofit was scored in the abovementioned prioritization categories. Stakeholders were also given the opportunity to include additional prioritization criteria. Because this is primarily a stormwater management retrofit project, some additional weight was given to those categories most critical to stormwater management: water quality treatment benefits, and flow control. This process identified the highest ranking retrofits within each Area of Primary Interest (API) as well as the overall highest ranking retrofits. Due to the age and nature of development in certain areas, some APIs were in more need of assistance than others. For example, the Lindvog Road Commercial Corridor was recently redeveloped with median plantings and bike lanes in the roadway, as well as sidewalks and a regional constructed wetland Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

16 treatment area. Because of the relatively new improvements in this area, identified retrofits were prioritized higher in other areas within the Study Boundary. Figure 3: Locations of Prioritized Retrofits The retrofit identification numbers reflect their prioritization. Retrofit #2 was identified by the County as a project that could be implemented almost immediately, and was constructed by Kitsap County crews during the summer of Retrofit #3 has been identified to be incorporated with SR 104 sidewalk improvement efforts by the County Roads department in coordination with WSDOT. Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

17 3.0 Approach for Preliminary Retrofit Designs 3.1 Street Sections A holistic and integrated approach is needed when evaluating the public rights of way. These transportation and utility conduits serve multiple purposes and needs, and should be efficiently utilized for stormwater management. When determining typical street sections for retrofits, it was first determined what each streetscape needed to be in support of previous and current planning efforts (i.e. sidewalks, bike lanes, parking, landscape, etc.) while also envisioning how each street would be used (i.e. a conduit to downtown, a local street, a connector from a commercial area to recreational areas, etc.). With those elements in mind, and with the intention of minimizing impervious surface, BMPs were selected that met the stormwater quality goals while supporting the other identified needs of each specific street and right of way. This type of retrofit can be installed incrementally as development and redevelopment occur. 3.2 Parking Lot Retrofits In addition to reviewing public areas, retrofit studies should also review potential private areas. Parking lots often offer significant opportunities for improvements. For this study, two parking lots were identified as potential retrofit opportunities. Each was evaluated differently one with pervious pavement, and the other with bioretention cells. These two examples stand alone as individual retrofits, while also serving as guides for potential improvements to other parking lots in the Study Area. It can be expensive to re grade or re pave an entire parking lot. Each parking lot s topography, use, and circulation were evaluated when determining an appropriate retrofit. For the retrofit including bioretention cells, low asphalt berms or channel drains may be installed to direct stormwater into existing planter areas. These planters could be enhanced into bioretention cells without disrupting traffic patterns. For the retrofit including permeable pavement, the layout of the parking stalls was rotated to be parallel with the contours allowing only the pavement in the stall areas to be replaced with permeable pavement in order to capture the sheet flow from the drive aisles in between each row of parking. 3.3 Site Specific Retrofits When evaluating a specific site to be retrofitted, it is important to keep in mind the source of the stormwater contributing to the site, the surrounding land uses, adjacent structures and infrastructure, as well as the prioritization criteria listed previously in this report. For example, if the stormwater tributary to a retrofit location contains a high concentration of fines or sediment, then a sump or catch basin may need to be installed upstream of the BMP. If a retrofit is adjacent to a steep slope or landslide area, infiltration should be avoided. After the site constraints and community plan elements have been adequately considered, BMPs should then be evaluated and designed based on their water quality, flow control, and aesthetic benefits. Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

18 4.0 Other Considerations 4.1 Additional Site Evaluations Additional geotechnical evaluations and survey information are needed for final design. Geotechnical work may include large and small scale infiltration testing, slope stability evaluation, cation exchange capacity testing, depth to groundwater (or other impermeable layer), and potentially a groundwater mounding analysis. 5.0 Summary The 47 retrofit projects identified during site reconnaissance and stakeholder meetings were identified based on stormwater management needs, stakeholder input, professional judgment, community need, and consistency throughout the Study Boundary. Of those 47 retrofit projects, the 13 that were prioritized for further consideration are described and illustrated in Appendix A of this report. Preliminary cost estimates for each of the retrofits are included in Appendix B. Notes and evaluation criteria from thorough site reconnaissance are included in Appendix C. The prioritization matrices are included in Appendix D. Kingston LID Stormwater Retrofit Plan Page ENGINEERING December 2012

19 Appendix A RETROFIT PROJECT SHEETS

20

21 KINGSTON LID RETROFIT KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

22 KINGSTON LID RETROFIT SITE INDEX AND PRIORITY LIST KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

23 KINGSTON LID RETROFIT SITE INDEX KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways LEGEND: STUDY BOUNDARY API 1 DOWNTOWN CORE API 2 VILLAGE GREEN API 3 SR104 CORRIDOR API 4 LINDVOG API 5 EAST SIDE

24

25 KINGSTON LID RETROFIT VILLAGE GREEN COMMUNITY PARK LAND USE TYPE: COUNTY RIGHT OF WAY 1 BEFORE Dulay Road NE NE West Kingston 1 AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways TYPICAL CROSS SECTION OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: The Village Green Community Park abuts NE West Kingston Road. This is one of the lowest areas in Kingston. Several drainages converge in this area before discharging to the Puget Sound. Improving the grassy swale along the frontage of the property into a raingarden will provide further treatment and flow attenuation for the tributary stormwater from the contributing roadways, landscapes, and pet exercise areas. This retrofit consists of a 4,500 s.f. raingarden with an overflow/collection structure which will connect to the existing storm drain beneath NE West Kingston Road Raingarden Swale - Water Quality improvement, flood control, aesthetics, public and private collaboration. 6 FLOOD DEPTH CATCH BASIN WITH ATRIUM GRATE 18 AMENDED SOIL 6 RIGID PERFORATED UNDERDRAIN PIPE 24 CLEAN PEA GRAVEL SCARIFIED SOILS

26 KINGSTON LID RETROFIT FIREHOUSE THEATRE LAND USE TYPE: COUNTY PROPERTY BEFORE 2 AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 1 TYPICAL CROSS SECTION 6 FLOOD DEPTH CATCH BASIN WITH ATRIUM 18 AMENDED SOIL 6 RIGID PERFORATED UNDERDRAIN PIPE 12 CLEAN PEA GRAVEL SCARIFIED SOILS OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: The Firehouse Theatre is located along SR 104 near the NE California Ave and SR 104 intersection. South of the Theatre lies the Kola Kole County Park. A steeply graded slope separates the two properties. Run-off from the Theatre parking lot, SR 104 and residential neighborhoods north-east of the site converge near the site causing significant accumulation in the northeast corner. Bank erosion could occur if continuous and sustained run-on volumes persist. A raingarden installed in the north-east corner will enhance water quality and flood control. A catch basin drop structure will be necessary to collect street level stormwater and safely convey it down to the raingarden area. A raingarden consisting of an 18 depth of amended soil over 12 (minimum) of pea gravel will provide treatment and flow attenuation for stormwater from SR104 corridor and the upper East Side Raingarden Cell- Water Quality, flood control, increased recreational opportunity, aesthetics, community plan support

27 KINGSTON LID RETROFIT KOLA KOLE PARK LAND USE TYPE: COUNTY RIGHT OF WAY BEFORE 3 AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 1 TYPICAL CROSS SECTION 6 FLOOD DEPTH CATCH BASIN WITH ATRIUM 18 AMENDED SOIL 6 RIGID PERFORATED UNDERDRAIN PIPE 12 CLEAN PEA GRAVEL SCARIFIED SOILS OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: A drainage ditch bordering NE Maine Ave directly south side of Kola Kole Park receives runoff from Maine Ave, SR 104, and the Park. Although it adequately collects water, installing a bioretention swale to detain and treat the runoff would benefit downstream properties and habitats. Additionally, the bioretention swale installation could serve as an environmental education tool for the neighboring pre-school and park. A raingarden swale consisting of 18 depth of compost amended soil over 12 (minimum) of pea gravel will provide treatment and flow attenuation for local runoff from the immediate surround area Raingarden Swale- Water Quality, flood control, aesthetics, education opportunity.

28 KINGSTON LID RETROFIT STATE ROUTE 104 LAND USE TYPE: STATE RIGHT OF WAY 4 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS PLAN VIEW AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways POTENTIAL LID STRATEGIES: SR 104 Corridor cross section includes three roadway segments from Washington Blvd NE to Lindvog Rd NE. The narrow roadway currently lacks pedestrian conduits and adequate stormwater management. The proposed road section will have two north-bound travel lanes for traffic exiting the ferry, and two southbound travel lanes. The sidewalks will be separated from the travel lanes by street tree biofilters, offering pedestrian security and pollution buffers, as well as sound buffers to the surrounding neighborhood Porous Sidewalk- Water Quality, pedestrian connectivity, increased recreational opportunity, community plan support 2. 2 Street Tree Biofilter- Water Quality, flood control, public private collaboration, aesthetics, community plan support 3 Porous Bike Lane - water quality, flood control, increased recreational opportunities, community plan support.

29 KINGSTON LID RETROFIT STATE ROUTE 104 LAND USE TYPE: STATE RIGHT OF WAY ` NE WEST KINGSTON RD. SR SECTION A 4 PERVIOUS CONCRETE 6 CHIPPED ROCK BIOFILTER SR SECTION B 4 PERVIOUS CONCRETE 6 CHIPPED ROCK BIOFILTER 6 PERVIOUS CONCRETE 6 CHIPPED ROCK SR 104 SECTION C AFTER TYPICAL SECTIONS KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 4 PERVIOUS CONCRETE 6 CHIPPED ROCK 6 PERVIOUS CONCRETE 6 CHIPPED ROCK PLAN VIEW

30 KINGSTON LID RETROFIT TYPICAL RESIDENTIAL CONNECTOR STREET LAND USE TYPE: COUNTY RIGHT OF WAY 5 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: Residential streets east of SR 104 and the downtown area will require upgrades as population and development increases. The sidewalks and bike lanes, which currently don t exist on many streets, encourage recreation and connect residents to their neighbors and community. Raingardens detain and filter stormwater runoff, simultaneously improving water quality and abating floods. Additionally, the optional parking creates beneficial space for residences. AFTER SECTION PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 4

31 KINGSTON LID RETROFIT TYPICAL RESIDENTIAL CONNECTOR STREET LAND USE TYPE: COUNTY RIGHT OF WAY PERVIOUS CONCRETE 6 CHIPPED ROCK 3 POROUS ASPHALT 6 CHIPPED ROCK 3 POROUS ASPHALT 6 CHIPPED ROCK 4 PERVIOUS CONCRETE 6 CHIPPED ROCK 18 COMPOST AMENDED SOIL TYPICAL SECTION EAST SIDE - CONNECTOR (OHIO, ILLINOIS, IOWA STREETS) AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 1. 1 Porous Sidewalk- Water Quality, flood control, pedestrian connectivity, public safety, increased recreational opportunity, community plan support Raingarden Swale- Water Quality, flood control, aesthetics, community plan support Optional parking- Parking Porous Bike Lane - water quality, flood control, increased recreational opportunities, community plan support.

32 KINGSTON LID RETROFIT N.E. WEST KINGSTON ROAD LAND USE TYPE: COUNTY RIGHT OF WAY 6 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways POTENTIAL LID STRATEGIES: NE West Kingston Rd lies on Kingston s south side near the Village Green Park. Kingston Rd is gently sloping towards a low point near the exit to the Village Green Park. Upstream storm system issues often converge in this low lying area, causing significant stormwater run-on and flooding that affects private properties. Stormwater accumulates at Lindvog Rd NE and the Village Green Park where runoff crosses over to the south side of the road and impacts private properties. Providing infiltration facilities to cut-off the flow of water such as porous sidewalks, bike lanes and raingardens would reduce run-on volumes to private properties as well as provide water quality treatment benefits.

33 KINGSTON LID RETROFIT N.E. WEST KINGSTON ROAD LAND USE TYPE: COUNTY RIGHT OF WAY KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 3 POROUS ASPHALT 6 CHIPPED ROCK 6 COMPOST AMENDED SOIL TILLED INTO TOP 12 EX. SOIL 18 COMPOST AMENDED SOIL 6 DIAMETER RIGID PERFORATED UNDERDRAIN 12 PEA GRAVEL TYPICAL SECTION NE WEST KINGSTON ROAD (LOOKING WEST) 6 COMPOST AMENDED SOIL TILLED INTO TOP 12 EX. SOIL Porous Sidewalk- Water Quality, flood control, community plan support Porous Bike Lane- Water Quality, flood control, community plan support Raingarden Planter - Water Quality, flood control, aesthetics, community plan support. *For future replacement, porous pavement should be used

34 KINGSTON LID RETROFIT THRIFTWAY GROCERY STORE PARKING LOT LAND USE TYPE: PRIVATE PROPERTY 7 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways POTENTIAL LID STRATEGIES: The Thriftyway Grocery Store is on the north side of SR 104 between Bannister St and Lindvog Rd NE. The large roof and impervious parking areas result in pooling water and contribute to downstream flooding. Similar to a roadway, automotive pollutants are deposited on the impervious area and washed to sensitive habitats downstream by stormwater. Installing raingarden cells (approximately 5% of the total parking lot area) to filter and infiltrate the stormwater decreases contributions to the County stormwater system by infiltrating the water at the point of origin, and allowing for evapotranspiration. Small berms or channel drains adjacent to the parking stalls direct the stormwater to the raingarden cells from the existing pavement surface with minimal cost and demolition.

35 KINGSTON LID RETROFIT THRIFTWAY GROCERY STORE PARKING LOT LAND USE TYPE: COUNTY RIGHT OF WAY COMPOST AMENDED SOIL 6 DIAMETER RIGID PERFORATED UNDERDRAIN TO STORM DRAIN 12 PEA GRAVEL TYPICAL SECTION THRIFTWAY PARKING LOT 1. 1 Raingarden Cell with Underdrain- Water Quality, flood control, public-private collaboration, aesthetics 2. 2 Berm or channel drain- Water quality, flood control, public-private collaboration KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

36 KINGSTON LID RETROFIT TYPICAL RESIDENTIAL LOCAL STREET LAND USE TYPE: COUNTY RIGHT OF WAY 8 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: Similar to the current connector streets, many East Side streets lack sidewalks, parking areas, and formal stormwater management facilities. Porous sidewalks and raingarden swales would help to infiltrate and filter any runoff from residential impervious surfaces. Since the local streets (NE E 2nd, 3rd, & 4th) run perpendicular to the steep embankment near Washington Blvd NE, infiltrating the East Side area stormwater at a safe setback distance (approximately 100, to be confirmed by geotechnical evaluation) prevents bank erosion and protects Puget Sound s water quality. The optional parking creates beneficial space for residences. PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

37 KINGSTON LID RETROFIT TYPICAL RESIDENTIAL LOCAL STREET LAND USE TYPE: COUNTY RIGHT OF WAY COMPOST AMENDED SOIL 6 DIAMETER RIGID PERFORATED UNDERDRAIN TO STORM DRAIN 12 PEA GRAVEL TYPICAL SECTION EAST SIDE - LOCAL (2 ND, 3 RD, 4 TH ) 4 PERVIOUS CONCRETE 6 CHIPPED ROCK 1. Porous Sidewalk- Water Quality, flood control, pedestrian connectivity, public safety, increased recreational opportunity, community plan support Raingarden Swale - Water Quality, flood control, aesthetics, community plan support Optional parking. KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

38 KINGSTON LID RETROFIT BANNISTER STREET LAND USE TYPE: COUNTY RIGHT OF WAY 9 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: Bannister Street (formerly W 1st St. NE) within the downtown sector connects two major thoroughfares, SR 104 and NE West Kingston Rd. Supported in the Community Plan, the new LID strategies include porous bike lanes, porous sidewalks, and bulbouts featuring raingarden cells. Water quality, flood control, recreational uses and pedestrian connectivity are just a few of the qualifiable benefits. PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

39 KINGSTON LID RETROFIT BANNISTER STREET LAND USE TYPE: COUNTY RIGHT OF WAY PERVIOUS CONCRETE 6 CHIPPED ROCK 3 POROUS ASPHALT 6 CHIPPED ROCK TYPICAL SECTION 18 COMPOST AMENDED SOIL 6 DIAMETER RIGID PERFORATED UNDERDRAIN 12 PEA GRAVEL BANNISTER STREET NE (FORMERLY W. 1 st STREET NE) KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 1. 1 Porous Bike Lane- Water Quality, flood control, increased recreational opportunities, community plan support Porous Sidewalk- Water Quality, flood control, pedestrian connectivity, increased recreational opportunities, community plan support Raingarden Bulb-Out Cells- Water Quality, flood control, parking, aesthetics. *For future replacement, porous pavement should be used

40 KINGSTON LID RETROFIT MAIN STREET LAND USE TYPE: COUNTY RIGHT OF WAY 10 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways POTENTIAL LID STRATEGIES: Main St. (currently the southbound lane of NE State Highway 104) is the heart of Kingston, WA. The heavy traffic results in pollution deposits on the impervious roadway surfaces. Porous pavement surfaces provide some treatment prior to infiltration (further geotechnical study needed to confirm infiltration and treatment capacity of insitu soils). Not only would porous bike lanes, parking and sidewalks allow infiltration to native soils and reduce contributions to the City s stormwater system, they also provide treatment prior to infiltration. Infiltration flow-through planters provide the enhanced treatment of a typical raingarden in an efficient, compact footprint to allow for maximum sidewalk width and parking stalls.

41 KINGSTON LID RETROFIT MAIN STREET LAND USE TYPE: COUNTY RIGHT OF WAY KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways TYPICAL SECTION MAIN STREET 1. 1 Center Planter- Maintains existing trees Porous Bike Lane- Local flood control, increased recreational use, community plan support Porous Parking- Water quality, local flood control, community plan support. 4 Porous sidewalk- Water Quality, flood control, pedestrian connectivity, public safety, increased recreational opportunity, community plan support. 5 Infiltration Flow-Through Planters - Water quality in small footprint, local flood control, aesthetics *For future replacement, porous pavement should be used

42 KINGSTON LID RETROFIT NE CALIFORNIA STREET RIGHT OF WAY LAND USE TYPE: COUNTY RIGHT OF WAY 11 OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: California St is currently partially developed. Connecting the existing dead end of Calfornia Street through to Lindvog Road would impact a sensitive wetland area. An elevated boardwalk extending over the native landscape connects pedestrians and cyclists from Bannister St and Lindvog Rd NE to the proposed Village Green Community Center with minimal impact. The multi-use boardwalk can accommodate both pedestrians and bicyclists safely without increasing impervious surface area. PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

43 KINGSTON LID RETROFIT NE CALIFORNIA STREET RIGHT OF WAY LAND USE TYPE: COUNTY RIGHT OF WAY 11 1 TYPICAL SECTION CALIFORNIA STREET ROW (ELEVATED BOARDWALK) 1. 1 Multi-use raised boardwalk- minimal wetland impact, pedestrian conductivity, increased recreational opportunities, public safety, public private collaboration, increased recreational opportunities, community plan support. KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways

44 KINGSTON LID RETROFIT PORT OF KINGSTON PARKING LOT LAND USE TYPE: PORT PROPERTY 12 PLAN VIEW KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: The Port of Kingston parking lot is a large impervious area bordering Appletree Cove. The elevation is low, the underlying soils are permeable, and it contains a vortex filter that removes some suspended solids prior to the stormwater reaching the final outfall in the Cove. Rotating the parking configuration 90 degrees allows the stalls to run parallel to the contours. The pavement in the parking stalls may then be replaced with porous pavement, allowing the runoff from the drive aisles to flow towards the porous stalls, and infiltrate into the sandy soils below. This reduces the performance demands on the vortex filter, and provides for better treatment and flow attenuation before the stormwater reaches the cove. If additional impervious surfaces are removed from the Port parking area, porous pavement should be placed in lieu impervious surfaces. A 12 chipped rock layer should also be installed under all porous surfaces to serve as an additional stormwater reservoir. A large sand filter could be installed beneath the pavement to treat and provide area for infiltration of contributing offsite stormwater flows as well.

45 KINGSTON LID RETROFIT PORT OF KINGSTON PARKING LOT LAND USE TYPE: PORT PROPERTY 12 1 FLOW FLOW TYPICAL SECTION PORT OF KINGSTON PARKING LOT DETAIL 1. 1 Porous Parking- Water quality, flood control, Kitsap County/Port of Kingston collaboration. KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways 3 POROUS ASPHALT 12 CHIPPED ROCK SCARIFIED SOILS TYPICAL CROSS SECTION

46 KINGSTON LID RETROFIT SR 104 AT ARCO LAND USE TYPE: STATE RIGHT OF WAY/ PRIVATE PROPERTY BEFORE 13 AFTER KITSAP COUNTY CLEAN STORMWATER Our Community, Our Waterways DETAIL 3:1 SLOPE OPPORTUNITIES AERIAL MAP POTENTIAL LID AREAS POTENTIAL LID STRATEGIES: A grassy swath in front of the Arco Gas Station would be a beneficial place for a raingarden cell. This site would filter and detain stormwater runoff from the gas station and neighboring businesses. It could also potentially filter and detain stormwater from the adjacent NE SR 104 and from the strip mall parking area across the street, benefitting downstream stormwater facilities and properties. A raingarden cell consisting of 18 depth of compost amended soil over 12 (minimum) of pea gravel will provide treatment and runoff flow attenuation Raingarden Cell- Water Quality, flood control, publicprivate collaboration, aesthetics. 6 FLOOD DEPTH 18 AMENDED SOIL CATCH BASIN WITH ATRIUM GRATE 6 RIGID PERFORATED UNDERDRAIN PIPE 12 CLEAN PEA GRAVEL SCARIFIED SOILS

47 Appendix B PRELIMINARY COST ESTIMATES

48

49 PRELIMINARY PROJECT COST ESTIMATES PROJECT NO. LOCATION INPUT QTY UNIT UNIT COST 1 4A 4B 4C VILLAGE GREEN COMMUNITY PARK SR104 CORRIDOR SECTION A SR104 CORRIDOR SECTION B SR104 CORRIDOR SECTION C 5 TYPICAL CONNECTOR STREET 6 N.E. WEST KINGSTON ROAD 7 THRIFTWAY GROCERY STORE PARKING LOT SUBTOTAL COST EXCAVATION 750 CY $9.93 $7,448 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 250 CY $30.83 $7,708 PLANTINGS (4500 SF) 2,000 PLANTS $4.90 $9,800 PEA GRAVEL (24") 333 CY $29.16 $9,720 CATCH BASIN WITH ATRIUM GRATE 1 EACH $2, $2,072 6" RIGID PERFORATED UNDERDRAIN PIPE 285 LF $13.83 $3,942 CONCRETE SIDEWALK REMOVAL 302 SY $17.15 $5,179 ASPHALT ROADWAY REMOVAL 1,293 SY $6.16 $7,964 EXCAVATION 456 CY $9.93 $4,528 CONCRETE CURB AND GUTTER 1,840 LF $23.57 $43,369 STREET TREE BIOFILTER 4 EACH $11, $44,000 SIDEWALK BASE COURSE 323 TON $21.44 $6,923 PERVIOUS CONCRETE SIDEWALK 11,636 SF $5.35 $62,253 EXCAVATION 624 CY $9.93 $6,192 ASPHALT ROADWAY REMOVAL 1,833 SY $6.16 $11,293 CONCRETE CURB AND GUTTER 731 LF $23.57 $17,230 TREE BOXES 2 EACH $11, $22,000 SIDEWALK AND BIKE LANE BASE COURSE 458 TON $21.59 $9,886 PERVIOUS CONCRETE SIDEWALK 9,334 SF $5.35 $49,937 PERVIOUS CONCRETE BIKE LANE 7,166 SF $5.35 $38,338 ASPHALT ROADWAY REMOVAL 2,611 SY $6.16 $16,084 SIDEWALK AND BIKE LANE BASE COURSE 1,306 TON $21.59 $28,187 PERVIOUS CONCRETE SIDEWALK 11,750 SF $5.35 $62,863 PERVIOUS CONCRETE BIKE LANE 11,750 SF $5.35 $62,863 EXCAVATION 4,204 CY $9.93 $41,741 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 2,211 CY $30.83 $68,169 PLANTINGS (39,800 SF) 17,689 PLANTS $4.90 $86,676 CATCH BASIN WITH ATRIUM GRATE 8 EACH $1, $13,864 6" RIGID PERFORATED UNDERDRAIN PIPE 2,587 LF $13.83 $3,942 POROUS PAVEMENT BASE COURSE 1,746 TON $21.59 $37,693 PERVIOUS CONCRETE SIDEWALK 26,437 SF $5.35 $141,438 POROUS ASPHALT PARKING 23,650 SF $2.15 $50,848 POROUS ASPHALT BIKE LANE 12,827 SF $2.15 $27,578 CONCRETE SIDEWALK REMOVAL 805 SY $17.15 $13,806 CONCRETE CURB 1,574 LF $35.45 $55,798 ASPHALT ROADWAY REMOVAL 1,667 SY $6.16 $10,268 EXCAVATION 1,244 CY $9.93 $12,353 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 733 CY $30.83 $22,598 PEA GRAVEL (12") 160 CY $29.16 $4,657 PLANTINGS (4,312 SF) 1,916 PLANTS $4.90 $9,388 6" RIGID PERFORATED UNDERDRAIN PIPE 1440 LF $13.83 $3,942 POROUS PAVEMENT BASE COURSE 617 TON $21.59 $13,329 PERVIOUS CONCRETE SIDEWALK 7,245 SF $5.35 $38,761 POROUS ASPHALT BIKE LANE 15,003 SF $2.15 $32,256 ASPHALT CONCRETE REMOVAL 704 SY $6.16 $4,337 EXCAVATION 821 CY $9.93 $8,152 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 352 CY $30.83 $10,847 PLANTINGS (6,333 SF) 2,815 PLANTS $4.90 $13,794 PEA GRAVEL (12") 235 CY $29.16 $6,840 CATCH BASIN WITH ATRIUM GRATE 11 EACH $2, $22,787 6" RIGID PERFORATED UNDERDRAIN PIPE 1,380 LF $13.83 $19,085 BERM 450 LF $10.08 $4,536 EXCAVATION 6,634 CY $9.93 $65,878 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 2,531 CY $30.83 $78,031 PEA GRAVEL (12") 1,676 CY $29.16 $48,870 PLANTINGS 20,111 PLANTS $4.90 $98,544 CATCH BASIN WITH ATRIUM GRATE 7 EACH $2, $14,501 6" RIGID PERFORATED UNDERDRAIN PIPE 930 LF $13.83 $12,862 SIDEWALK BASE COURSE 576 TON $21.59 $12,432 POROUS CONCRETE SIDEWALK 20,750 SF $5.35 $111,013 EXCAVATION 518 CY $9.93 $5,145 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 167 CY $30.83 $5,138 CATCH BASIN WITH ATRIUM GRATE 3 EACH $2, $6,215 6" RIGID PERFORATED UNDERDRAIN PIPE 368 LF $5,089 PLANTINGS (3,000 SF) 1,333 PLANTS $4.90 $6,532 PAVEMENT BASE COURSE 452 TON $21.59 $9,766 PERVIOUS CONCRETE SIDEWALK 5,500 SF $5.35 $29,425 POROUS ASPHALT PARKING 3,250 SF $2.15 $6,988 POROUS ASPHALT BIKE LANE 7,550 SF $2.15 $6,988 CONCRETE SIDEWALK REMOVAL 2,550 SY $17.15 $43,733 ASPHALT ROADWAY REMOVAL 2,429 SY $6.16 $14,962 EXCAVATION 1,702 CY $9.93 $16,903 PRECAST CONCRETE RAINGARDEN STRUCTURE 708 LF $ $77,880 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 105 CY $6.16 $647 PLANTINGS 1,333 PLANTS $4.90 $6,532 PEA GRAVEL (12") 70 CY $29.16 $2,041 PAVEMENT BASE COURSE 1,243 TON $21.59 $26,847 PERVIOUS CONCRETE SIDEWALK 22,950 SF $5.35 $66,126 POROUS ASPHALT PARKING 12,360 SF $2.15 $20,425 POROUS ASPHALT BIKE LANE 9,500 SF $2.15 $20,425 8 TYPICAL LOCAL CROSS STREET $442,130 9 BANNISTER STREET $81, MAIN STREET $296, CALIFORNIA STREET BOARDWALK 640 LF $ $330,000 $330,000 REMOVING ASPHALT PAVEMENT 5,878 SY $6.16 $36, PORT OF KINGSTON PARKING LOT EXCAVATION 2,606 CY $9.93 $25,876 PAVEMENT BASE COURSE 1,468 TON $21.59 $31,694 $226,026 POROUS ASPHALT PARKING 52,900 SF $2.50 $132,250 EXCAVATION 428 CY $9.93 $4,248 COMPOST AMENDED SOIL (TYPE 1 COMPOST) 183 CY $30.83 $5, SR 104 AT ARCO PLANTINGS (3,300 SF) 1,467 PLANTS $4.90 $7,188 CATCH BASIN WITH ATRIUM GRATE 1 EACH $2, $2,072 $24,757 6" RIGID PERFORATED UNDERDRAIN PIPE 147 LF $13.83 $2,033 PEA GRAVEL (12") 122 CY $29.16 $3,564 TOTAL $40,688 $174,216 $154,876 $169,996 $471,948 $217,158 $90,377