Design Criteria Package for pocket park in NE Portland

1. 2013
Prepared By:
EGI (Group 11): Bruno DeToledo, Anndee
Huff, Eli Jefferson, Kate Petak, Joe Wendt
Submitted to:
Tom Szymoniak
CE 484
3/19/2013
DESIGN CRITERIA PACKAGE
Sabin Triangle

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Executive Summary
The Sabin community will stand to gain from the wide breadth of experience and expertise
offered by the diverse team of engineers at Engineering Gratis Inc. (EGI). Whether the project
involves transportation, environmental, or structural engineering, our inter-disciplinary team
has all of the qualifications necessary to provide cost-effective solutions.
The Sabin Community Association is interested in developing a pocket park on the southwest
corner of NE 15th and Prescott, referred to as Sabin Triangle, to showcase the historical
Irvington Trolley of the early 1900s, as well as to create a neighborhood gathering space. EGI
will lead the stormwater portion of the design process for Sabin Triangle. Through extensive
analysis of the existing site and subsequent communication with the city officials and the
project representatives, we will strive to design a modern solution that meets the city
requirements and achieves the clients’ goals of creating an attractive neighborhood pocket
park. EGI will provide specific technical assistance pertaining directly to the stormwater
drainage system currently operating in the Sabin Triangle as well as oversee the redesigning of
the system to meet the requirements of the city of Portland’s Stormwater Management
Manual (SWMM). We are a team of local engineers with the technical experience necessary to
provide both quality services and cost-effective methodologies to meet our clients’ goals and
deadlines.
This project has been in development since 2010, and preliminary designs have been made by
Architects Without Borders in conjunction with input from the neighborhood association. The
timeline for our involvement in the project is January 2013 through June 2013. By June, the
group plans to deliver 30% engineering plans to the neighborhood. The following information is
contained within this design criteria package:
• Project Goals and Objectives
• Existing Conditions
• Design Inputs
• Alternative Analysis with Recommended Alternative
• Implementation Challenges and Mitigation
• Final Design Workplan
• Appendix
This document will serve to outline the current state of the project and what EGI plans to
accomplish by June 2013.

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Table of Contents
Executive Summary.......................................................................................................................................1
Table of Contents..........................................................................................................................................2
Project Goals and Objectives ........................................................................................................................3
Existing Conditions .......................................................................................................................................4
Design Inputs…………………………………………………………………………………………………………………………………………..6
Alternative Analysis.......................................................................................................................................8
Implementation Challenges and Mitigation ...............................................................................................10
Final Design Workplan ................................................................................................................................11
Appendix………………………………………………………………………………………………………………………………………………17
Comments from Draft DCP……………………………………………………………………………………………………………………20

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Project Goals and Objectives
Problem Statement
The Sabin Community Association has raised money in order to create a pocket park on
a currently unused city-owned site at the southwest corner of NE Prescott St and NE
15th Avenue. With a preliminary conceptual design already developed by Architects
Without Borders, it is the role of EGI to determine the feasibility of their design as well
as aid in navigating city requirements for stormwater runoff, ADA accessibility,
maintenance of underground utilities on the site, and permits.
Summary of Previous Studies and Investigations
The Sabin Community Association met with the city of Portland in October 2011 to
discuss improvements to the site designed by Architects without Borders. Requirements
from the city were as follows:
• If existing sidewalks are damaged during construction, they must be rebuilt to new
specifications (0.5 ft curb, 4 ft planter area, 6 ft sidewalk, and 1.5 ft frontage zone)
• The proposed sign location is approved, but the content should be appropriate
• The adjacent property owners (1452 & 1460 NE Prescott, 4407 NE 15th Ave) and
the designers need to have an agreement about the driveway alignments
• The driveway design should not affect access to the adjacent private properties
• No bioswales should be built on top of the existing water line
• The existing street corner does not meet current ADA standards and will need to
be reconstructed
• The stormwater runoff must meet the requirements of the City of Portland’s
Stormwater Management Manual, and the stormwater hierarchy must be
addressed.
• A public works permit is required in order to construct in the public right-of-way.
• Stormwater calculations and a geotechnical report must be submitted to the city
• Site improvements must accommodate maintenance of the existing sewer line;
these will be determined during the Public Works Process
Stakeholder Involvement
The stakeholders involved are the Sabin Community Association and the City of
Portland. The Sabin Community Association has raised money in order to fund the
improvements to the site, but the city must make sure stormwater and ADA standards
are being met on the site because it is city-owned property.

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Sustainability Considerations
Sustainable design is being used wherever possible. For this site, the most applicable
element is stormwater management, where the goal is to maintain all runoff from the
site using bioswales so that there are minimal impacts on the sewer system.
Existing Conditions
The site is located on the southwest corner of the intersection of NE Prescott Street and NE
15th Avenue in Portland, OR. Referred to as Sabin Triangle, the parcel is city-owned property
that acted as the terminus of the historic Irvington Trolley in the early 1900s. In order to
showcase this history and create a neighborhood gathering space, the community has been
working with Architects Without Borders to develop a concept plan. Currently, the corner has a
6 foot sidewalk around the perimeter. The area of the site is approximately 5100 ft2. Most of
the area is paved, but there are a few trees in the planter zone as well as in the triangle area of
the site.
There are two driveways on the south side of the site: the northernmost is access to the market
located on Prescott just west of the site and the second is a private driveway leading to a
residence. There are large concrete blocks delineating the northernmost of the two driveways.
Additionally, there is a bus shelter and stop for Line 8, which is a frequent service line running
from NE Dekum Street to Marquam Hill in SW Portland. There are two cobrahead street lights
on the project site and two pay phones. Across the street on Prescott are several popular
businesses including Pok Pok Noi and Grain and Gristle. Nearby parks to the site include Sabin
HydroPark (0.16 miles), Roselawn City Park (0.41 miles), Two Plum City Park (0.47 miles), and
King School Park (0.50 miles).
The Sabin Community Association has been working with Architects Without Borders since
2010 in order to create a design for a pocket park on this site. Figure 1 shows the aerial view of
the intersection. Figure 2 is a street view of the project site, Figure 3 shows a pocket park in a
nearby neighborhood, and Figure 4 shows a design proposed by Architects Without Borders.

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Figure 1: Intersection of NE Presctt Street and NE 15th Avenue
Figure 2: Proposed Project Site
Figure 3: Pocket Park at NE Holman Street and NE 13th Avenue (Photo Credit: Greg Raisman)

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Figure 4: Proposed Design by Architects Without Borders
Design Inputs
The design and construction of Sabin Triangle Park is in effort to enhance and expand the
utilization and function of community space in the Sabin Neighborhood. To create a space that
has appropriate and safe function, EGI must consider the following items.
Design Standards (Code or other relevant and appropriate regulations)
The design services provided by EGI shall be in accordance with current editions of all
applicable codes, standards and regulations. Stormwater design shall be in compliance with the
City of Portland Stormwater Manual. This includes designing for a 25 year storm to be
contained on site. Other design components shall meet the following:
• ADA Standards (5% maximum grade)
• Public Works Permit
• City or Portland Zoning Code
• City of Portland Pedestrian Design Code
• Other Design Standards (such as wind load calculations for the sign using ASCE7
Chapter 26)
Review and approval will be through the City of Portland Department of Transportation, Water
Bureau and Bureau of Environmental Services.

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Environmental Factors (Geotechnical, stormwater, erosion and sediment)
• EGI will investigate the following environmental factors to be considered for design. Soil
type and water table levels are needed for stormwater design.
o Soil type
o Groundwater levels
o Soil contamination
Risk Management
Managing risks for change of project scope are important to the success of the project since
the scope significantly influences the cost, schedule and quality of the deliverables. There
is a low level of risk associated with potential changes in the scope of the current phase of
the project. There is a larger level of risk associated with later phases since they are
dependent on the results from the current phase.
Specifically, location of the waterline and sanitary line influence the design of the designed
graded center of the park and the location of stormwater facilities. Additionally, quality of
existing pipelines may influence project feasibility due to the associated costs and repair or
relocations. Soil contamination could also influence project feasibility due to associated
costs for necessary disposal. Other risks to scope include change of input from stakeholders.
This would likely affect cost or schedule depending on input type.
Issues or requests need to be clearly defined and communicated in a timely manner. Any
changes to scope must be approved with appropriate change to cost and schedule if
needed.
Permit and Land Use Requirements
The proposed Sabin Triangle Park location lies entirely in the public right-of-way. A revocable
(encroachment) Public Works Permit is required for development of this location. Additionally,
stormwater calculations and a geotechnical report are required to determine method of
stormwater disposal and to obtain a permit.
Other requirements include design of the site’s frontages to the recommended sidewalk
corridor width and configuration provided by the City. The design must also not conflict with
adjacent property access and current accessibility must be maintained. Finally, stormwater
features must not be located above existing water mains.

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Safety
This project design will comply with applicable safety standards and requirements. Appropriate
protective equipment and must be wore and utilized by personnel on site during the course of
construction.
Quality Control Requirements
The design firm will be responsible for periodic inspection of the project to ensure the quality
control and quality assurance standards of EGI are being met. The final quality requirements
must be accepted by the client after provided the certification of 100% completion and
required, agreed documents.
Alternative Analysis
Selection Criteria
This project will be implemented as a base project with optional alternatives. The base
project outlines the results and data that the group will produce while working on the
Sabin Triangle. Any alternatives will be designed by Architects Without Borders and
approved by the Sabin Community. Factors that may influence architects and the Sabin
Community include life cycle costs, aesthetics, and stakeholder acceptance.
o Survey of property; The survey will allow for key information such as
runoff to be calculated
o The location of utilities will be necessary in determining the cost of the
overall project
o Estimation of water level and runoff will be important in determining if
the use of bio swales is possible.
o Obtain any permits necessary to further the progress of the project
o Alternatives will be suggested to architects and the community.
Alternatives Evaluated
Alternatives must fit the requirements determined from the base scope of the project
and meet the criteria set forth by the City of Portland.
• Rain Gardens (in existing AWB design)

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• Retention Basin
o If bioswales are deemed unsuitable for the area, the use of a retention
basin may serve as a possible alternative.
• Traditional versus permeable paving
Cost Estimates and Comparisons
• The current estimate of the project is just over $200,000 (see budget) based on
the original estimate of the renovation by Architects Without Borders.
• Based on the results of the base project, revisions will be made to this estimate.
• According to protectedwithpride.org the long-term costs of the rain garden will be
minimal especially if taken care of by the community. Once plants are established
occasional inspection, weeding, and mulch replacing is all that is typically
necessary.
• The cost of a retention basin would be dependent on its size. For example, a
100,000 cubic foot retention basin is estimated to cost $250,000 for installation
and $3,000 a year for maintenance.
Constructability
Once the base project has been completed, the constructability of the project will be
evaluated. Items for consideration include how to build the rain garden without
affecting the existing water line. The retention basin would be significantly harder to
build and maintain, whereas once the rain garden is built, the yearly maintenance is
very low.
Recommended Alternative
Rain Gardens
o The rain garden will allow rainwater runoff from the impervious section
of the project to be absorbed into the ground. This reduces rain runoff
by allowing storm water to infiltrate into the ground (as opposed to
flowing into storm drains and surface waters which causes erosion, water
pollution, and diminished groundwater).
o Proximity of the proposed rain garden to the existing water line may
create a need to relocate either the rain garden or the water line.

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Relocation of Waterline
o If the water line is determined to be too shallow for construction, then
the water line will need to be relocated.
o Once the base project has been completed, the cost and life cycle
estimate for the relocation of the waterline can be determined.
Permeable Pavement
o Permeable pavement allows for the movement of storm water through
its surface allowing for the reduction of runoff and effectively trap
suspended solids and filter pollutants from the groundwater.
o Life Cycle Cost
• According to a 2009 EPA study, porous asphalt costs nearly twice
as much as regular hot mix asphalt. Also according to
rochesterstormwater.com porous asphalt is also more expensive
to maintain and is less durable than hot mix asphalt. Given the
communities already limited financial situation for the project, the
use of permeable pavement is not a realistic option.
Implementation Challenges and Mitigation
Constructability
Constructability issues for the project will be identified and documented by EGI.
Strategies for resolving anticipated issues will also be devised and included in the
estimated costs.
Operation and Maintenance Considerations
Operations and maintenance will be the responsibility of the clients and
ultimately the Sabin Neighborhood. Design features that will require routine
maintenance includes stormwater facilities and vegetated areas.
Environmental
All construction projects must follow stormwater standards in the Stormwater
Management Manual.

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Permit and Property
All projects are to be conducted in accordance with the City of Portland and the
Public Works Permit requirements. There is the potential for road closure and
impact of traffic on NE 15th
and NE Prescott during construction.
Stakeholder Acceptance
Throughout design, interaction with stakeholders through charettes and
community meetings will ensure stakeholder approval and acceptance. Final
quality requirements will be approved by client.
Final Design Workplan
Scope
The scope of services can be divided into two phases:
Phase 1:
• Survey the property to identify additional factors such as runoff
• Locate utilities to determine where bioswales can be placed on the site. The depth
and location of these utilities is essential to ensure that they are preserved in their
existing condition
• Determine the water level, soil type, infiltration rate
• Estimate the storm water runoff in order to determine the appropriate type of
bioswale to be used, as well as to approximate the storm water runoff for the area
to ensure that city mandated requirements are adhered to
• Obtain necessary permits.
Phase 2:
• Deliver 30% engineering plans. Considerations include re-constructing the sidewalk
to meet ADA standards if the existing sidewalks are damaged and determining
alignment for the driveway from NE 15th
. Plan sheets will tentatively include:
oDetails of bioswales
oSection of Site
oSite Plan
oLandscape Plan
oTopographic Survey
oTemporary Traffic Control Plan

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• Feasibility Report, which will include the following:
oExecutive Summary
Outline the problem to be addressed
Identify the scope of the project
Give a preliminary indication of any areas within the scope which may
be desirable but not essential
Section should state the recommended solution, including the reasons
for this choice, and should refer to the details in the alternatives section.
oProject Summary
Project Background
Problems
Scope, Schedule, and Budget
oMethodology and Alternatives Analysis
Advantages and disadvantages of solutions, cost/benefit comparisons
Description of solution’s impact on existing systems
Expected benefits
Feasibility
o Final Recommendation and Conclusion
• Present plans to neighborhood and build consensus
The survey has already been completed by the other capstone group. Additionally, the water
level, soil type, and infiltration rate has been identified. From this point forward, EGI is
responsible for:
• Developing the stormwater management plan for the site
• Determining how the existing utilities will affect project design. Two possible
designs can ensue going forward; either the design will need to be altered due to
the water line or the water line can be relocated in order to accommodate the
existing design.
• Researching the history of land use on the site and possibly testing the soil for
contamination
• Obtaining permits (jointly with other team)
• Developing 30% engineering plans (jointly with other team)

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Schedule
The schedule below shows the time frame allotted for each task.
Feb
11
Feb
25
March
11
March
25
April
1
April
15
April
29
May
13
May
27
Community Engagement
Pipeline Location Data
Collection
Pipeline Location Survey
Stormwater Calculations
Permit Obtainment
Project Delivery
This project has been in development since 2010, and preliminary designs have been made by
Architects Without Borders in conjunction with input from the neighborhood association. The
timeline for our involvement in the project is January 2013 through June 2013. By June, the
group plans to deliver 30% engineering plans to the neighborhood.
Budget
The proposed budget for the project is estimated to be $203,562 for all essential and
discretionary items. This estimate was put together by the City of Portland in 2010. See the
table developed by the City of Portland below for the breakdown of costs.

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Approach to Procurement
In modern organizations and design, procurement is a team exercise. Generally, the larger the
project, the larger the team needs to be to ensure that individuals are properly allocated to
tasks that meet their qualifications. Such is the case with the Sabin Triangle. Each of our team
members will play a key role in the project; tailored to their specific skill set. Having a team of
individuals that each bring unique, as well as necessary skills, to a project not only mitigates risk
by limiting the ability of any one individual to dominate in the decision making process, but it
also allows the decision-making process to be more or less equal across the team.
In Phase 1, our group will be responsible for locating the utilities and estimating the stormwater
runoff. Both of the groups involved in the project will share the responsibility of obtaining all
necessary permits.

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Design Deliverables
The first task of the project is to determine the location and depth of the water and sewer lines
that run directly under the proposed improvements location at the corner of NE 15th Ave and
NE Prescott St. Methods available to locate these pipelines include accessing maps and data
from the City of Portland, surveying, and physical determination via vactor truck. A document
describing location details and pipe conditions will be submitted by the Project Manager and
Project Engineer to the Sabin Neighborhood Board.
Design and Stakeholder Team
The stakeholders involved are the Sabin Community Association and the City of Portland. The
Sabin Community Association has raised money in order to fund the improvements to the site,
but the city must make sure storm water and ADA standards are being met on the site because
it is city-owned property.
Appendix
Design Computations
Rough estimates from Google Earth show that the site is approximately 7500 ft2 as a
conservative value. From the City of Portland’s Stormwater Management Manual, our site will
require a public works permit, so we will use their Presumptive Approach in evaluating the
facility. This will require infiltration testing. The City of Portland requires analysis of flow rate
based on a 25 year storm event using the rational method. The calculation using the rational
method follows:
Q=CiA
where C=0.9 for paved surface
i=3.32 inches/hr
A=5100 ft2
Q=(0.9)*(3.32 in/hr)*(5100 ft2)*(1 ft/12 in)*(1 hr/3600 s)
Q=0.35 ft3/s
Soils Report
The factors to note in the report below are:
• Slope is 5-8%

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• Infiltration rate: the most limiting layer transmits water at 0.57-1.98 in/hr
• Soil is well drained
• Depth to water table is 80 feet
• No flooding or ponding on the site
• Loam to 56 inches deep; Very gravelly sandy loam 56-66 inches deep

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Comments from Draft DCP

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