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Final Project Concept Report

Cabrito Paseo Walkway/Bike Path Proposition O Project November 3, 2006

Prepared for:

City of Los Angeles Department of Public Works

Bureau of Sanitation Watershed Protection Division

A 523 West 6th Street, Suite 400

Los Angeles, CA 90014

Source: CDM

i Final Cabrito Paseo Walkway-Bike Path.doc

Contents

Executive Summary .............................................................................................................. ES-1 ES.1 Project Overview ................................................................................................... ES-1 ES.2 Project Costs and Schedule................................................................................... ES-3 ES.3 Implementation Schedule..................................................................................... ES-5

Section 1 Introduction .................................................................................................. 1-1 1.1 Project Objectives......................................................................................................1-1 1.2 Overview of Project ..................................................................................................1-1

Section 2 Existing Project Site Characteristics ......................................................... 2-1 2.1 Land Use and Jurisdictional Boundaries...............................................................2-1

2.1.1 Community Plan and Zoning..................................................................2-3 2.2 Current Environmental Setting ..............................................................................2-5

2.2.1 Hydrology ..................................................................................................2-6 2.2.2 Geology and Hydrogeology ....................................................................2-6 2.2.3 Biology ........................................................................................................2-6 2.2.4 Recreations and Open Space....................................................................2-7 2.2.5 Environmental Studies .............................................................................2-7

Section 3 Description of Proposed Project ............................................................... 3-1 3.1 Overview of Proposed Project ................................................................................3-1

3.1.1 Proposition O Funded ..............................................................................3-1 3.1.2 Project Elements Not Funded by Proposition O...................................3-4 3.2 Water Quality Benefits.............................................................................................3-4 3.3 Additional Project Benefits......................................................................................3-5

Section 4 Proposed Project Siting............................................................................... 4-1 4.1 Siting Location and Construction Constraints ....................................................4-1 4.2 Environmental Feasibility .......................................................................................4-2

Section 5 Operations and Maintenance .................................................................... 5-1

Section 6 Regulatory Requirements........................................................................... 6-1 6.1 Environmental Review ............................................................................................6-1 6.2 Permit Requirements................................................................................................6-1

Section 7 Public Outreach Program ........................................................................... 7-1 7.1 Stakeholders ..............................................................................................................7-1

Section 8 Preliminary Cost Estimates ........................................................................ 8-1

Section 9 Implementation Schedule .......................................................................... 9-1

ii Final Cabrito Paseo Walkway-Bike Path.doc

Section 10 Project Recommendations........................................................................ 10-1

Appendices Appendix A References Appendix B Other Sources of Funding Documentation Appendix C Letters of Support Appendix D Pollutant Load Model Results

ES-1 Final Cabrito Paseo Walkway-Bike Path.doc

Executive Summary This report provides a conceptual overview and feasibility assessment of the potential to create the Cabrito Paseo Walkway/Bike Path (Walkway/Bike Path).

ES.1 Project Overview Storm water runoff from a site has the potential to contribute trash, oil and grease, suspended solids, metals, gasoline and pathogens to the storm water conveyance system. The Cabrito Paseo Walkway/Bike Path Stormwater Best Management Practices (BMP) project goal is to minimize, to the maximum extent practicable, the introduction of pollutants of concern that may result in significant impacts, generated from site runoff to the storm water conveyance system. Pollutants of concern consist of any pollutants that exhibit one or more of the following characteristics:

Current loadings or historic deposits of the pollutant impact the beneficial uses of receiving water bodies.

Elevated levels of the pollutant are found in sediments of receiving water and/or have the potential to bioaccumulate in organisms therein.

The detectable inputs of the pollutant are at concentrations or loads considered potentially toxic to humans and habitats.

Targeted pollutants include the following:

Oil and grease

Suspended solids

Metals

Nutrients This project is consistent with several water-related planning efforts underway in the vicinity of the project. Planning efforts include the City of Los Angeles Integrated Resources Plan, Integrated Regional Water Management Plan, Tujunga Watershed Project, Pacoima Wash Project, and Common Ground. These plans collectively aim to improve water quality, reduce potable water use, and enhance waterways and habitat

In meeting this specific requirement, “minimization of the pollutants of concern” will require the incorporation of a BMP or combination of BMPs best suited to maximize the reduction of pollutant loadings in runoff to the Maximum Extent Practicable.

Proposed stormwater best management practices along this project site include:

Installation of bioswales

Executive Summary


Installing a “smart” irrigation system to reduce runoff when compared to traditional irrigation systems

Installing trash screens at drain inlets within the site

Installing tree wells and landscaping to aid in filtration

Installation of a decomposed granite walkwaye

The subwatershed surrounding the Walkway/Bike Path is mostly urbanized and residential with very little open space. The City of Los Angeles, Bureau of Sanitation-Watershed Protection Division has indicated that the underlying storm drain system at the site serves an area of approximately 502 acres. A one-hour one year storm, using an impervious area of 73 percent and a runoff coefficient of 0.68, results in a runoff volume of 58.74 acre-feet.

Sheet flow to the site is contributed by approximately 16.29 acres. A one-hour one year storm, using an imperviousness of 41 percent and a runoff coefficient of 0.43, results in a sheet flow runoff volume of 1.19 acre-feet.

There is the potential for several water quality benefits at the Walkway/Bike Path site, including both dry weather and wet weather runoff management. These benefits will assist in complying with current and future TMDL regulations, as the project drainage area is tributary to the Los Angeles River. The total estimated pollutant removal percentages from the combination of bioswales and trash capture devices are shown in Table ES-1.

Table ES-1 Estimated BMP Pollutant Removal

Pollutant Percent Pollutant Removal

Total Suspended Solids 62

Heavy Metals 17-75

Oil and Grease 88

Total Kjeldahl Nitrogen 17

Refer to Appendix D and Section 3.2 for pollutant model results and discussion of water quality benefits.

This project is consistent with the City of Los Angeles Integrated Resources Plan goals of protecting public health and safety, effectively managing system capacity, protecting the environment, enhancing cost efficiency, protecting quality of life, and promoting education. The plan specifically encourages neighborhood solutions,

Executive Summary


promoting water self-sufficiency, enhancing public lands, and enhancing efficient use of natural resources.

Additionally, the plan is consistent with the goals of the Integrated Regional Water Management Plan (IRWMP) and Common Ground.

Proposed stormwater enhancements include a “smart” irrigation system, bioswales, trees wells and landscaping, a graded decomposed granite walkway which will direct flow to the bioswales, and trash screens at drain inlets within the project site. Figure ES-1 of this report shows the concept site design for a sample portion along the length of the project site.

Figure ES-1. Site Layout for the Proposed Cabrito Paseo Walkway/Bike Path

The proposed facilities will provide pre-treatment of stormwater prior to entering the storm drains by screening trash to prevent it from entering the storm drain as well as providing biofiltration of the flow. The “smart” irrigation system will reduce dry weather runoff volume and the use of potable water for irrigation of the landscaped areas at the site. The Walkway/Bike Path project will also provide an underserved community with a valuable community recreation facility.

ES.2 Project Costs Costs are broken down into two categories: Water Quality Improvement Costs and Other Beneficial Improvements Costs. Proposition O requested funds for Water Quality Improvements total $1,337,696.

Source: CDM

Executive Summary


Other secured funding sources to be used for non-water quality improvements or other beneficial improvements include $15,000 from Kaiser Permanente.

The following costs are raw total unit construction costs and are not marked-up. Total marked up costs are provided in Table 8-1.

Water Quality Improvements Costs

Construction Costs: Bioswales $151,000 Irrigation System $259,182 Smart Irrigation Controller $45,300 Trash Screen at Drain Inlets $1,500 Trees (15 gallon to 36 inch box) $67,950 Decomposed Granite Walkway $24,196 Landscaping $17,500 Water Quality Improvements Costs Subtotal $566,628 Other Beneficial Improvements Costs Bike Path (asphalt-concrete 4” depth with 6” aggregate base) $114,540 Wall $972,440 Lighting (bollard lights) $90,600 Security Gate $10,570 Other Beneficial Improvements Costs Subtotal $1,188,150

The estimated total project budget (request and other funds, excluding annual operations and maintenance) is approximately $4.46 million. Total requested Proposition O funding is approximately $1.3 million.

The incremental increase in O&M costs due to the proposed project is $140,000 per year based on the assumption that operation and maintenance costs will be approximately 8% of the total estimated raw capital costs (City of Los Angeles BOS-WPD). There is no existing O&M cost to the City of Los Angeles at this location, therefore the total O&M will be the incremental increase of $140,000 per year.

Executive Summary


ES.3 Implementation Schedule Based on the best information available during preparation of this Concept Report, the project design and construction will be completed by September 2009.

Figure ES-2. Implementation Schedule

J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J S O

CEQA/NEPA Preparation and Completion

Pre-Design

Project Design

Permitting Identification and Acquisition

Contract Bid and Award Process

Construction Duration Y Y Y Y

Post Implementation, Construction and Monitoring Efforts

2010Work Item

2007 2008 2009

1-1 Final Cabrito Paseo Walkway-Bike Path.doc

Section 1 Introduction The purpose of this concept report is to provide a conceptual overview and assessment of the proposed Cabrito Paseo Walkway/Bike Path (herein Walkway/Bike Path). The lead applicant is Los Angeles Neighborhood Land Trust, partnered with the Los Angeles Bureau of Sanitation, Watershed Protection Division.

1.1 Project Objectives The overall project goal is to reduce trash, heavy metals, total suspended solids, and nitrogen in order to aid the City in meeting the Total Maximum Daily Load (TMDL) requirements in the watershed. The project plans to accomplish this goal through:


Installation of a decomposed granite walkway.



Installation of trash screens at drain inlets within the site

Additional Benefits The Walkway/Bike Path Project is also intended to improve recreational opportunities in an underserved community. The project location currently promotes public safety issues and it is expected that the project will reduce crime in the area by preventing illegal dumping as well as providing recreational opportunities for local youth after-school and on weekends.

1.2 Overview of Project As described in greater detail below, the Walkway/Bike Path would improve water quality by creating bioswales that would receive sheet flow from the surrounding community and project site, as well as by eliminating an area that is often overrun with trash. Along the path, tree wells and landscaping will be installed to help with water management and filtration of stormwater. Trash screens would be installed at drain inlets within the project site. A smart irrigation system would reduce runoff and potable water demands as compared to a traditional irrigation system. The location is currently an unused stretch of right-of-way which is overgrown and used for illegal dumping, and therefore the existence of the Walkway/Bike Path will greatly improve the community and provide recreational opportunities in a neighborhood with limited open space.


Section 2 Existing Project Site Characteristics 2.1 Land Use and Jurisdictional Boundaries The proposed site for the Cabrito Paseo Walkway/Bike Path is located in the City of Los Angeles, less than ½ mile east of the 405 Freeway and approximately 4 miles north of the 101 Freeway. The neighborhood is considered Panorama City, which is a fairly urbanized, low income community, with limited community facilities. The location falls within the jurisdiction of the Sixth Council District. Figure 2-1 shows the neighborhood of the project location.

Figure 2-1. Neighborhood of the Cabrito Paseo Walkway/Bike Path.

Los Angeles River

Tujunga Wash

Tujunga Wash

Pacoima Wash

Bull Creek

East Canyon Channel

Cabrito Paseo Walkway / Bike

Path

2-2

Final Cabrito Paseo Walkway-Bike Path.doc

The site is a “paper” street approximately 2300 feet in length and 40 feet in width, bordered to the north by residences along Marson Street, to the south by the Union Pacific Railroad and a self-storage facility, to the west by the planned Marson Street Pocket Park and Sepulveda Boulevard, and to the east by the Pacoima Wash. Figure 2-2 shows the project location. The area available on the site for all structures incorporated into the Walkway/Bike Path is approximately 2 acres.

Figure 2-2. Proposed Location for the Cabrito Paseo Walkway/Bike Path.

Cabrito Paseo Walkway / Bike

Path

Pacoima Wash

2-3


The property is considered a street within the City of Los Angeles and therefore does not have associated County Assessor’s Parcel, Tract or Lot Numbers. The site had been historically paved with asphalt, and was essentially an extension of Cabrito Street to the west of Sepulveda Boulevard, but it is now overgrown with weeds and other vegetation.

2.1.1 Community Plan and Zoning Land use within the project drainage area is detailed in Figure 2-3 along with a breakdown of land use composition by percentage of total land use.

Figure 2-3. Land Use within the Project Drainage Area

2-4


Table 2-1 includes a breakdown of the pollutant loading by land use type.

Table 2-1 Pollutant Loading by Land Use Type

Pollutant Unit High Density

Residential

Light

Industrial Vacant Total Per Acre

Total Coliform MPN/10 15,845.03 1,175.92 4.53 17,025.48 1045.15

Fecal Coliform MPN/10 10,821.00 876.03 0.69 11,697.72 718.09

Fecal Enterococcus MPN/10 7,072.29 254.35 0.33 7,326.98 449.78

Total Suspended Solids mg/l 242.84 137.06 20.23 400.13 24.56

Oil & Grease mg/l 3.32 0.97 0.00 4.29 0.26

Total Aluminum ug/l 1.53 1.04 0.18 2.76 0.17

Total Copper ug/l 0.04 0.02 0.00 0.06 0.00

Total Lead ug/l 0.03 0.01 0.00 0.04 0.00

Total Nickel ug/l 0.00 0.01 0.00 0.01 0.00

Total Zinc ug/l 0.20 0.36 0.01 0.57 0.04

Dissolved Copper ug/l 0.02 0.01 0.00 0.03 0.00

Dissolved Zinc ug/l 0.11 0.23 0.00 0.34 0.02

Nitrate as N mg/l 2.20 0.50 0.11 2.81 0.17

Total Kjeldahl Nitrogen mg/l 7.41 1.71 0.09 9.21 0.57

The Mission Hills – Panorama City – North Hills Community Plan (Community Plan) is the document specifying the specific goals and objectives for the neighborhood in the future. It identifies current land use issues and identifies which direction the community has indicated it wants to go in the future. According to the Community Plan, the area has seen some inconsistent land use developments over the years that have created issues for the community. To resolve these issues, the Community Plan identifies goals and objectives which are summarized as follows:

Residential: Encourage appropriately scaled new housing in proximity to new transportation facilities, as well as residential and mixed uses along commercial corridors. Improve access and proximity to employment.

Commercial: Encourage development of shopping areas to serve the neighborhoods, as well as the Major Site of Opportunity, Panorama Regional Center. Ensure appropriate transitions between commercial (mixed use) and adjoining uses, especially residential. Create "shopper friendly" retail areas; incorporate street trees and landscape, benches, convenient parking /access, and maintain commercial frontage at ground level.

2-5


Industry: Generate employment for the local work force with the abundance of manufacturing use sites, particularly those that improve the economic and physical condition of the area. Attract industry with excellent access to regional freeways and rail services.

Open Space: Accelerate the addition, expansion and/or improvement of local parks throughout the Community. Establish a system of equestrian trails.

The site is located just north of the established boundaries for the Mission Hills – Panorama City – North Hills Community Plan Area. This area encompasses approximately 12 square miles of diversified uses in a historic part of Los Angeles. The population in this area, according to the 2000 census was 135,057 with a population density of approximately 11,555 people per square mile. The community is represented by the Panorama City Neighborhood Council.

Within the area, land use is primarily residential to the north, with commercial and industrial uses to the south, east, and west. Sepulveda Boulevard, a Major Highway Class II, and the 405 Freeway are the main north-south corridors accessible from the site. The eastern side of the site is bordered by the Pacoima Wash rather than a roadway, however, further east of the Wash, Van Nuys Boulevard is also a Major Highway Class II. The main east-west corridors near the site are Roscoe Boulevard, a Major Highway Class II to the north, and Saticoy Street, a Secondary Highway to the south.

The proposed Walkway/Bike Path site is not zoned under the City of Los Angeles’ General Plan, however the adjacent parcels are. To the north, the area is zoned consistent with the Residential (R1) Land Use and the area to the south is zoned consistent with the Manufacturing (M1) Land Use. The area around the Pacoima Wash to the east is designated as Open Space (OS) and the creation of the Walkway/ Bike Path facility would be consistent with this land use and would not conflict with current adjacent zoning designations.

2.2 Current Environmental Setting The proposed project site is an unused City of Los Angeles right-of-way, a paper street known as Cabrito Paseo. The site had been historically paved with asphalt but is now overgrown with weeds and other vegetation. Illegal dumping commonly occurs in the area. Three storm drain inlets owned by Los Angeles County Flood Control District are present on the site, which drain directly into the underlying storm drain that discharges to the Pacoima Wash and ultimately to the Los Angeles River. The site is graded to discharge runoff into these three inlets, and conditions currently mimic an unmaintained bio-swale. The largest of the three inlets receives surface water runoff from the adjacent Marson Street and Noble Avenue. Conditions at the site currently lead to the conveyance of sediment, trash, vegetative matter, bacteria, and other pollutants directly into the storm drain system.

2-6


2.2.1 Hydrology Watershed Description The storm drains at the project location drain directly to the Pacoima Wash, which is within the Tujunga Subwatershed, the largest subwatershed within the Los Angeles River Watershed. The headwaters of the Pacoima Wash are located in the Angeles National Forest in the San Gabriel Mountains. The Pacoima Wash drains into the Tujunga Wash both north of the project site and again south of the project site. South of the project location, the Pacoima Wash flows underground before it enters the Tujunga Wash. The Tujunga Wash, from the Hansen Dam to the Los Angeles River, is listed on the USEPA’s 303d list as impaired for multiple pollutants, however the Pacoima Wash is not listed as impaired. Ultimately, the Tujunga Wash drains into the Los Angeles River.

Subwatershed Tributary Area The subwatershed surrounding the Walkway/Bike Path is mostly urbanized and residential with very little open space. The City of Los Angeles, Bureau of Sanitation-Watershed Protection Division has indicated that the underlying storm drain system at the site serves an area of approximately 502 acres. A one-hour one year storm, using an impervious area of 73 percent and a runoff coefficient of 0.68, results in a runoff volume of 58.74 acre-feet.

Sheet flow to the site is contributed by approximately 16.29 acres. A one-hour one year storm, using an imperviousness of 41 percent and a runoff coefficient of 0.43, results in a sheet flow runoff volume of 1.19 acre-feet.

2.2.2 Geology and Hydrogeology A Phase One Environmental Assessment conducted at the site stated that no known or suspect environmental conditions are present. Surficial soils are described as urban land with variable properties. Quaternary Alluvium of the Cenzoic Era underlies the surficial soils. The soil would likely be amenable to infiltration, but further investigations are warranted to verify localized site conditions.

2.2.3 Biology The project location is an overgrown paper street adjacent to railroad tracks, manufacturing facilities, residences, major roadways, and the channelized Pacoima Wash. The majority of the surrounding area is urbanized. These disturbed habitats support a variety of species including non-native grasses and weeds, American crow, rock dove, Northern mockingbird, common sparrow and pigeon and Brewer’s blackbird. Other wildlife species potentially found within the area could include western fence lizard, feral dogs and cats, and various species of bats, ground squirrels, possums and raccoons.

2-7


2.2.4 Recreation and Open Space Parks The Mission Hills – Panorama City – North Hills Community Plan states that while the community parks within the Plan area meet the need of the existing population, the community is deficient in the number of neighborhood parks. The Community Plan establishes the goal of creating adequate recreation and park facilities that meet the needs of the community. A number of the policies established by the Community Plan for recreation and park space to achieve this goal include the following:

Preserve and improve existing recreational facilities and park space, by designating them Open Space (OS) Zones.

Consider utilizing existing public lands such as flood control channels, utility easements, or Department of Water and Power property, to provide facilities for specialized recreational needs.

Acquire and develop properties as small parks, on the order of ½ an acre, where there is not sufficient acreage for neighborhood parks.

In addition, the Community Plan identifies the Open Space policies as follows:

Preserve passive or visual open space.

Protect significant environmental resources from environmental hazards.

Accommodate active parklands and other open space uses in areas designated and zoned as Open Space.

Accessibility & Other Resources The community is well served by public transit services, with several bus lines along Sepulveda Boulevard, Roscoe Boulevard, and Saticoy Street, connecting to larger mass transit services including the Metro Orange and Red rail lines. In addition to public transportation, there are bike lanes in the area, including a commuter bikeway that is a part of Roscoe Boulevard. If in the future a bikeway is constructed adjacent to the Pacoima Wash, then the proposed bikeway could possible link to it.

2.2.5 Environmental Studies A Phase One Environmental Assessment has been conducted for the site; however no preliminary endangerment assessments (PEAs) have been conducted.

A 3-1


Section 3 Description of Proposed Project 3.1 Overview of Proposed Project The Walkway/Bike Path includes water quality elements that will be funded by Proposition O, as well as supporting elements that will be funded by other sources.

The project is expected to be completed in September 2009, with CEQA documentation filed by July 2007. Figure 3-2 below shows a representative site layout for a portion of the length of the Walkway/Bike Path.

3.1.1 Proposition O Funded The elements of the project that will be funded by Proposition O are those that are directly related to the improvement of water quality. Detailed design of each element will be conducted once grant funding is received and surveying is completed. Elements proposed for Proposition O funding include:



Installing trash screens at drain inlets within the site


Installation of a decomposed granite walkway

Bioswales Bioswales, also known as vegetated filter strips or biofilters, are engineered swales utilized to convey runoff and naturally pre-treat stormwater. Stormwater is conveyed through broad, shallow channels with dense vegetation covering the sides and bottom of the channel. These open channel systems are alternatives to impervious curb and gutter stormwater conveyance systems. These systems slow stormwater runoff, capture pollutants, and promote infiltration. Swales tend to be most effective when slopes are between two and six percent to increase the time for treatment, and when water depths do not exceed the vegetation height. Bioswales can either be dry, collecting runoff as it occurs, or wet, where the swale holds standing water and a wetland is

Section 3 Description of Proposed Project


established. Dry bioswales are proposed for this project. Collecting stormwater in dry bioswales provides pre-treatment of runoff, after which runoff can be diverted either for infiltration or to a stormdrain, reducing peak storm event discharges.

“Smart” Irrigation System The term “Smart” Irrigation refers to the use of irrigation controllers to monitor irrigation, based on actual weather data and soil moisture content. In addition to reducing the amount of water used by limiting irrigation (i.e. no irrigating after a storm event when the soil is already saturated), the units would also reduce or eliminate over-watering, a significant contributor to dry weather runoff. A “Smart” Irrigation device reduces the amount of over irrigation by anywhere from 20 to 80 percent and reduces the amount of runoff from over irrigation by 60 percent (CH: CDM, 2004).

Trash Screens To aid in meeting the existing trash TMDL for the LA River, trash capture devices will be installed on the three drain inlets within the project site. The Cities of Burbank, Glendale, La Canada Flintridge and Pasadena (Four-cities) submitted a request to the Regional Water Quality Control Board, Los Angeles Region for certification for an innovative trash capture method. The system proposed by the Four-cities is a two part system that includes (1) a brush material, similar to a mud flap used on large truck, installed over the catch basin opening, and (2) a metal mesh with slot size just smaller than 5-milimeters installed slightly above the opening of the outlet pipe. On May 4, 2005 the Four-cities received approval from the regional board. A similar system to that of the Four-cities is proposed for the drain inlets.

Site Landscaping Site landscaping, in the form of planting tree wells, will increase the biological uptake of pollutants. Additionally, the trees will provide habitat, shade and aesthetic appeal.

Graded Decomposed Granite Walkway A graded decomposed granite walkway will be built on the south side of the paper street and will be graded to direct flow to the bioswales. The walkway will be adjacent to the bike path (on the north side) and will be composed of decomposed granite. The walkway will be 4 ft. in width total.



3.1.2 Project Elements Not Funded by Proposition O Supporting elements of the project that will not be funded by Proposition O include a bike path and safety elements. Kaiser Permanente has pledged $15,000 in matching funding to improve the community by aiding in the completion of the project.

Asphalt-Concrete Bike Path The bike path will be composed of asphalt-concrete and will feature 4 foot wide lanes in each direction with a 2 foot wide shoulder to either side. The bike path will be strong enough to support police vehicles. The bike path will be adjacent to the decomposed granite pathway.

Safety Elements To ensure the proper use of and safety within the project location, several features are included within the project. A security gate will be installed at the main entrance on the west side of the Walkway/Bike Path to prevent vandalism and loitering at nighttime. A minimum 6 foot high concrete wall will be installed on the north side of the site to separate the project area from the adjacent residences and preserve the residential privacy and security. Bollard lighting will be installed along the trail every 40 feet so that the pathway is illuminated in the evening hours both for users of the pathway and to assure that the area is visible for police surveillance.

3.2 Water Quality Benefits Proposed Project BMPs There is the potential for several water quality benefits at the Walkway/Bike Path site, including both dry weather and wet weather runoff management. These benefits will assist in complying with current and future TMDL regulations. The total estimated pollutant removal percentages from the combination of bioswales and trash capture are shown in Table 3-1.

Table 3-1 Estimated BMP Pollutant Removal

Pollutant Percent Pollutant Removal

Total Suspended Solids 62

7Heavy Metals 17-75

Oil and Grease 88

Total Kjeldahl Nitrogen 17

Bioswales Bioswales trap particulate pollutants, such as suspended solids and trace metals, and provide filtration of flow through both the vegetation and the subsoil matrix.



Bioswales also promote infiltration of flow, reducing the total volume and peak of runoff reaching the storm drain, and promote infiltration.

Trash Screens Trash capture devices will prevent trash from entering the underlying storm drain system and traveling to the Los Angele River, which has an adopted TMDL for trash.

3.3 Additional Project Benefits The Walkway/Bike Path will provide a large benefit for a community that does not currently have sufficient neighborhood recreation facilities. The community will likely be involved in the operations and maintenance of the park as well, which will create job opportunities within the area. The Los Angeles Neighborhood Land Trust intends to pay a stipend to community members who rotate being in charge of locking and unlocking the security gate, as well as those that may take part in other maintenance activities.

This project also fits in with the goals of several water-related planning efforts underway in the vicinity of the project. The overall goals and efforts of these planning projects as they relate to the proposed project are described below:

Pacoima Wash Project – The project aims to develop recreational use along the portion of the wash in the City of San Fernando, in conjunction with habitat restoration and habitat connectivity.

Los Angeles Integrated Resources Plan – The plan is an integrated approach to wastewater, runoff management and recycled water with six main objectives: protect public health and safety, effectively manage system capacity, protect the environment, enhance cost efficiency, protect quality of life, and promote education. The Plan specifically encourages neighborhood solutions and the use of abandoned alleys and vacant lots in the east valley region for onsite percolation.

Integrated Regional Water Management Plan – A plan being developed to obtain Proposition 50 funding. It encourages integrated regional strategies for water resources management and the use of competitive grants to provide funding for projects that protect against drought, improve water quality, and reduce dependence on the potable water supply.

Tujunga Watershed Project – A watershed management plan aimed at maximizing groundwater recharge, optimizing water reuse, and improving water quality.

Common Ground – A plan for the San Gabriel and Los Angeles Rivers, with guiding principles of growing a greener southern California, enhancing water and waterways, and planning together to make it happen.


Section 4 Proposed Project Siting 4.1 Siting Location and Construction Constraints Design Criteria In order to design the proposed project, the existing site conditions need to be analyzed. The site will need to be graded so that the water slowly flows by gravity from the walkway/bike path area to the bioswales and ultimately the storm drains. Grading will also be required to direct flows to the bioswales from the northern side of the project location.

The bioswales must be planted with vegetation that can withstand periodic inundation with significantly drier conditions much of the time, particularly during the dry summers experienced in this region. The vegetation will act as a physical barrier to trash in the diverted runoff, and therefore periodic removal of trash from the bioswales, as well as the trash screen devices at drain inlets, will be required.

The bioswales should also be designed to maximize retention time in order to increase the pollution removal potential. They should be designed to treat a minimum of 1.19 acre-feet total. The bioswales will direct flow into the storm drain system and the capacity of the storm drains must be considered. The bioswale should be designed so that the water level does not exceed 2/3 of the height of the grass or 4 inches, whichever is less, at the design treatment rate. Longitudinal slopes should be a maximum of 2.5%.

Additionally, the design of the bioswales may need to include vector control. Early consultation with local vector control district experts will alleviate vector issues for the subject Stormwater Enhancements. Chemicals or biological controls should be used to control mosquitoes before they emerge as adults. Sources would be treated with either Bacillus thuringiensis var. israelensis (Bti) or methoprene (Altosid). Bti is a microbial agent formulated as crystalline bacterial spores. These spores are ingested by mosquito larvae and cause the cell walls of the larval digestive system to burst. Methoprene is a synthetic insect growth regulator that mimics naturally occurring hormones in the mosquito's body. Methoprene disrupts the mosquito's normal life cycle causing the adult mosquito to fail to emerge from the pupae. Both of these controls are safe to the environment and target specific. If the breeding source is active with pupae, the source can be initially treated with Agnique MMF. Agnique MMF is a mono molecular film which suffocates the mosquito pupae and larvae. Since pupae do not feed, they must be killed by suffocation.

Construction Constraints There are several construction constraints that need to be taken into consideration. Since the site is located in a residential area, adjacent to several backyards, construction scheduling needs to be done such that the surrounding neighborhoods are not drastically impacted by the construction activities. As one of the goals is to

Section 4 Proposed Project Siting


improve the neighborhood for its residents, the impact on the residents during construction is an important consideration, which will include noise, the frequency and duration of street closures, truck traffic, street sweeping, watering the site during grading activities to reduce dust, etc.

Also, as the location has experienced criminal activity in the past, something the project hopes to eliminate, it will be important to take precautions to avoid vandalism and theft of materials and equipment during the construction process. It is recommended that the staging area include covered and locked storage units to minimize these types of problems.

4.2 Environmental Feasibility Runoff that flows to the site arrives via the existing storm drain system as well as via sheet flow from Marson Street. Three storm drain inlets are located along the length of the proposed project site and convey sheet flow to the underlying storm drain. The largest inlet is located downstream of where Noble Avenue intersects Marson Street, which is an area where it is expected that the majority of surface flow will enter the site. Bioswales will be constructed to capture the maximum amount of flow possible given the size constraints of the site.

The “smart” irrigation system will be located throughout the site for watering the bioswales, tree wells and other landscaping during dry weather.

As the site currently has no existing recreational program elements, construction of the proposed facilities should not have an impact on recreational aspects of the site, although there may be temporary and intermittent noise and aesthetic impacts on the adjacent residents and the planned Marson Street Pocket Park.

Items that may need to be procured include the “smart” irrigation system, trash screens, plants, paving material, and security components, such as the gate and lighting fixtures.


Section 5 Operations and Maintenance Regular upkeep of the bioswales and pathway components will be necessary. The irrigation system will need to be periodically inspected to assure proper functioning. The vegetation in the bioswales will require maintenance including periodic mowing, weed control, reseeding, and clearing of debris, sediment and blockages. The landscaped tree well areas will also require upkeep. The decomposed granite and asphalt concrete utilized on the walkway and bike path will require inspection for damage and repair as necessary, and the security elements should be observed for any maintenance needs.


Section 6 Regulatory Requirements This section describes the environmental review process and appropriate regulatory requirements for the project. 6.1 Environmental Review For purposes of this Concept Report, it is assumed that a Mitigated Negative Declaration will be required for the proposed project.

The City of Los Angeles anticipates commencing with CEQA documentation in February 2007, following Proposition O funding approvals. Under the assumed Mitigated Negative Declaration schedule, CEQA should be complete approximately six months after the expected February 2007 start date or approximately July 2007.

6.2 Permit Requirements During construction, there are several state and local permits that will be required to be obtained by the contractor. The following is a preliminary list of these permits:

1. Construction General Permit issued by State Water Resources Control Board (SWRCB) which includes the Storm Water Pollution Prevention Plan (SWPPP)

2. Traffic Control Plan

3. Erosion Control Plan

4. Access Plan

5. Floodplain Mapping Review

6. National Pollutant Discharge Elimination System Permit


Section 7 Public Outreach Program 7.1 Stakeholders The Bureau of Sanitation will be responsible for the planning phase of the proposed project. The Bureau of Engineering and Bureau of Street Services will jointly be responsible for the design and implementation phases of the proposed project. Interested stakeholders include: Los Angeles Neighborhood Land Trust, Kaiser Permanente, Councilman Tony Cardenas – 6th Council District, and North East Trees.


Section 8 Preliminary Cost Estimate Table 8-1 below provides preliminary information regarding the costs associated with implementation of the wetland park. Cabrito Paseo Walkway/Bike Path Proposed Project Costs Costs are broken down into two categories: Water Quality Improvement Costs and Other Beneficial Improvements Costs. Proposition O requested funds for Water Quality Improvements total $1,337,696.

Other secured funding sources to be used for non-water quality improvements include $15,000 from Kaiser Permanente.

The following costs are raw total unit construction costs and are not marked-up. Total marked up costs are provided in Table 8-1.

Water Quality Improvements Costs

Construction Costs: Bioswales $151,000 Irrigation System $259,182 Smart Irrigation Controller $45,300 Trash Screen at Drain Inlets $1,500 Trees (15 gallon to 36 inch box) $67,950 Decomposed Granite Walkway $24,196 Landscaping $17,500 Water Quality Improvements Costs Subtotal $566,628 Other Beneficial Improvements Costs Bike Path (asphalt-concrete 4” depth with 6” aggregate base) $114,540 Wall $972,440 Lighting (bollard lights) $90,600 Security Gate $10,570 Other Beneficial Improvements Costs Subtotal $1,188,150

The estimated total project budget (request and other funds, excluding annual operations and maintenance) is approximately $4.46 million. Total requested Proposition O funding is approximately $1.3million.

The incremental increase in O&M costs due to the proposed project is $140,000 per year based on the assumption that operation and maintenance costs will be approximately 8% of the total estimated capital costs (City of Los Angeles BOS-WPD).

Section 8 Implementation Costs


There is no existing O&M cost to the City of Los Angeles at this location, therefore the total O&M will be the incremental increase of $140,000 per year.

Water Quality Benefits Cost

Other Project Benefits

(a)

Construction Cost (including estimating contingency, moblization, allowances,

construction contengency, and material cost escalation

$1,007,558 $2,400,607 $3,408,165

(b) Land Purchase/Right-of-Way acquisition $0 $0 $0

(c)Pre-Design and Design (including

environmental clearance, design project management)

$221,674 $499,432 $721,106

(d) Construction and Post-Construction management $108,464 $225,274 $333,738

(j) Grand Total [Sum (a) through (d) for each column] $0 $1,337,696 $3,125,313 $4,463,009

Table 8-1. Project Cost Estimate Table

Budget Category Non-Proposition O Funding (if applicable)

Sources of Non-Proposition O Funds

Total Requested Proposition O

Section 8 Implementation Costs


Basis of Estimate All cost mark-ups for items a-j were developed by the Bureau of Engineering. Assumptions include the following:

Mobilization – 7% of total construction unit costs

Permit Allowances – 3% of total construction unit costs

Other Allowances – 5% of total construction unit costs

Estimating Contingency – 20% of subtotal of mobilization, permit allowances, other allowances, and total construction unit costs

Escalation – 10% of subtotal of estimating contingency, mobilization, permit allowances, other allowances, and total construction unit costs; per year for three years

Construction contingency – 10% of subtotal of escalation, estimating contingency, mobilization, permit allowances, other allowances, and total construction unit costs.


Section 9 Implementation Schedule Based on the best information available during preparation of this Concept Report, the project design and construction will be completed by Spring 2009. No buildings exist at the site that will require demolition. A staging area for construction vehicles will be at the south of the intersection of Noble Avenue and Marson Street and traffic control measures, according to the approved traffic control plan, will be implemented along affected streets.

Figure 9-1. Implementation Schedule

J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J S O

CEQA/NEPA Preparation and Completion

Pre-Design

Project Design

Permitting Identification and Acquisition

Contract Bid and Award Process

Construction Duration Y Y Y Y

Post Implementation, Construction and Monitoring Efforts

2010Work Item

2007 2008 2009


Section 10 Project Recommendations In summary, the following project recommendation should be considered:

1. Tree and other vegetation selection should be done by a landscape architect familiar with vegetation that is subject to periodic inundation and flooding during the wet season.

2. Site investigation studies should be conducted prior to proceeding with the stormwater quality improvements proposed in this Concept Report.

3. The applicant should continue to work with the City and other stakeholders to seek further BMP options at additional locations.


Appendix A References California Resources Agency. “The California Environmental Quality Act.” 2005. http://ceres.ca.gov/topic/env_law/ceqa/stat/

California Stormwater Quality Association. “Stormwater Best Management Practice Handbook, New Development and Redevelopment.” January 2003. Available at: http://www.cabmphandbooks.com CH:CDM. “City of Los Angeles Integrated Resources Plan, Facilities Plan, Volume 3: Runoff Management.” July 2004. Prepared for City of Los Angeles Department of Public Works, Bureau of Sanitation and Department of Water and Power. City of Los Angeles. “City of Los Angeles General Plan, Transportation Element, Bicycle Plan, Bikeway Maps.” Accessed July 11, 2006. http://www.ci.la.ca.us/PLN/Cwd/GnlPln/TransElt/BikePlan/BikeMaps.htm City of Los Angeles. “City of Los Angeles General Plan, Transportation Element, Highways & Freeways.” Accessed July 10, 2006. http://www.ci.la.ca.us/PLN/Cwd/GnlPln/TransElt/TE/HwyFwy.htm City of Los Angeles. “Council District Map.” 2002. Available at: http://www.lacity.org/council/cd2/doc/City_Map.pdf City of Los Angeles. “Mission Hills – Panorama City – North Hills Community Plan.” May 2001. Available at: http://cityplanning.lacity.org/complan/pdf/msscptxt.pdf City of Los Angeles Department of City Planning. “Population & Housing Estimates, Summary Data by Community Plan Area.” Accessed June 19, 2006. http://cityplanning.lacity.org/DRU/Locl/LocRpt.cfm?geo=CP&sgo=CT City of Los Angeles Department of City Planning. “Zoning Information & Map Access System.” Accessed July 10, 2006. http://zimas.lacity.org/ Los Angeles County Office of the Assessor. “Parcel Viewer.” Accessed June 9, 2006. http://assessormap.co.la.ca.us/mapping/viewer.asp Los Angeles Neighborhood Land Trust. “Proposition O Project Submittal Form: Cabrito Paseo Walkway/Bike Path.” 2005. Proposition O Project Review Committee. “2005 Fall Funding Cycle Categorization of Projects: Recommendations of the Project Review Committee.” February 9, 2006.


Appendix B Other Sources of Funding Documentation


Appendix C Letters of Support


Appendix D Pollutant Load Model Results

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